Innovative Construction and Building Materials

Topic Information

Recent research in construction and building materials has focused on the development and characterization of innovative materials to improve the quality of the overall infrastructure and lower the environmental impact. This leads to environmentally friendly (and sustainable) processes and circular economy.

Physicochemical studies have facilitated the recognition, definition, and assessment of several initiatives in this regard, leading to the identification of technologies, techniques, materials, and approaches with several benefits for the construction industry and its processes.

It is our pleasure to invite you to submit papers for this Topic on “Innovative Construction and Building Materials”. Papers describing experimental results, applying techniques, and proposing models and analytical approaches for developments in the field of construction and building materials, as well as reviews, opinions, commentaries, and comments and reports, are welcome.

Research topics include but are not limited to:

• Functional innovative materials;
• Sustainable processes;
• Composites;
• New materials from wastes;
• Synthesis of novel materials;
• Characterization techniques;
• New aspects in constructions and building materials.

We look forward to receiving your contributions to this Topic which will provide an overview of the high-quality research going on in the physico-chemistry (synthesis and development) of innovative materials for application in the construction industry.

Regards,

Prof. Dr. Cesare Oliviero Rossi
Dr. Pietro Calandra
Dr. Paolino Caputo
Prof. Dr. Bagdat Teltayev
Dr. Valeria Loise
Dr. Michele Porto
Topic Editors

Keywords

Participating Journals

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Applied Sciences applsci	2.5	5.3	2011	17.8 Days	CHF 2400
Buildings buildings	3.1	3.4	2011	17.2 Days	CHF 2600
Infrastructures infrastructures	2.7	5.2	2016	16.8 Days	CHF 1800
Materials materials	3.1	5.8	2008	15.5 Days	CHF 2600
Polymers polymers	4.7	8.0	2009	14.5 Days	CHF 2700

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Published Papers (57 papers)

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8 pages, 2009 KiB  

Open AccessArticle

Dissolution of Magnesia in Silicate Melts and Diffusivity Determination from CLSM Studies

by Burhanuddin and Harald Harmuth

Appl. Sci. 2023, 13(14), 8458; https://doi.org/10.3390/app13148458 - 21 Jul 2023

Cited by 1 | Viewed by 768

Abstract

Magnesia is one of the vital and extensively used refractory components. In this study, the dissolution of magnesia is investigated at 1450, 1500, and 1550 °C in three silicate slags in the CaO–Al₂O₃–SiO₂–MgO system using high-temperature confocal [...] Read more.

Magnesia is one of the vital and extensively used refractory components. In this study, the dissolution of magnesia is investigated at 1450, 1500, and 1550 °C in three silicate slags in the CaO–Al₂O₃–SiO₂–MgO system using high-temperature confocal laser scanning microscopy to determine its effective binary diffusivity. The pore-free fragments of single-crystal fused magnesia particles were used, and the effects of experimental parameters and slag properties on the dissolution of magnesia were assessed. The ranking of dissolution times in the three slags at the three temperatures did not agree with the trend expected from the CaO/SiO₂ ratio of each slag. Instead, several quotients serving as reference numbers were tested. The effective binary diffusivities were calculated considering all the impacting phenomena and parameters. The diffusivities of magnesia at 1500 °C in the slags with CaO/SiO₂ weight ratios of 0.65, 0.93, and 1.17 are 2.67 × 10⁻¹⁰, 1.81 × 10⁻¹⁰, and 3.20 × 10⁻¹⁰ m²/s, respectively. The diffusivity of magnesia in one of the three slags was compared with rotating finger test results, which showed good agreement. The plausibility of diffusivity was checked using an Arrhenius plot. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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12 pages, 1362 KiB  

Open AccessArticle

Numerical Simulation of the Performance of Self-Healing Concrete in Beam Elements

by Khalid Alkhuzai, Luigi Di Sarno, Abdullah Haredy, Raed Alahmadi and Danah Albuhairi

Buildings 2023, 13(3), 809; https://doi.org/10.3390/buildings13030809 - 19 Mar 2023

Viewed by 2045

Abstract

The formation of cracks in concrete structures occurs due to a multitude of causes ranging from shrinkage to external loading and environmental exposure. This phenomenon can significantly affect the lifecycle of concrete structures. Self-healing concrete (SHC) is considered a promoted innovation capable of [...] Read more.

The formation of cracks in concrete structures occurs due to a multitude of causes ranging from shrinkage to external loading and environmental exposure. This phenomenon can significantly affect the lifecycle of concrete structures. Self-healing concrete (SHC) is considered a promoted innovation capable of overcoming this inevitable occurrence. In accordance with current SHC development processes, this paper utilizes the numerical simulation approach to test the performance of reinforced SHC beam specimens modeled using the commercial software ABAQUS 6.14 (Vélizy-Villacoublay, France). This paper aims to contribute to the scarce literature on SHC models by utilizing the overlooked dicyclopentadiene (DCPD) agent and ambiguous variability of crystalline admixtures. The SHC is introduced to the beam models at various depths and analyzed using load against displacement curves compared with a reference model of ordinary concrete. The effects of SHC on the mechanical properties of structural elements were determined. The results show a distinct improvement of the load-carrying capacity of SHC beams, indicating an efficient contribution of SHC in structural applications. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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12 pages, 3493 KiB  

Open AccessArticle

Economic Integrated Structural Framing for BIM-Based Prefabricated Mechanical, Electrical, and Plumbing Racks

by Seungchan Baek, Jongsung Won and Sejun Jang

Appl. Sci. 2023, 13(6), 3677; https://doi.org/10.3390/app13063677 - 14 Mar 2023

Cited by 1 | Viewed by 1978

Abstract

Prefabrication, one of the methods to increase productivity by moving construction activity to factory work, has evolved into multi-trade prefabrication. Although previous studies have introduced the merits and directions of multi-trade prefabrication technology, various design and installation techniques must be developed for the [...] Read more.

Prefabrication, one of the methods to increase productivity by moving construction activity to factory work, has evolved into multi-trade prefabrication. Although previous studies have introduced the merits and directions of multi-trade prefabrication technology, various design and installation techniques must be developed for the economical application of multi-trade prefabrication. This study aims to provide an economical design for prefabricated mechanical, electrical, and plumbing (MEP) rack (PMR) structural framing. We proposed five types of PMR structural framing techniques and analyzed their required channel material and labor inputs through a pilot test. The efficiency of PMR structural frames was examined by adjusting the supporting interval, moving the duct outside, and removing the upper framing. Economics and productivity analysis revealed that removing the upper framing method was the most effective when the coordination period was secured. Adjusting the supporting intervals is also an economical design option. The findings of this study can help enhance the economic feasibility of prefabrication and modularization of construction and their widespread utilization. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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16 pages, 4452 KiB  

Open AccessArticle

Physical and Chemical Effects in Blended Cement Pastes Elaborated with Calcined Clay and Nanosilica

by Divino Gabriel Lima Pinheiro, Matheus Ian Castro Sousa, Fernando Pelisser, João Henrique da Silva Rêgo, Amparo Moragues Terrades and Moisés Frías Rojas

Materials 2023, 16(5), 1837; https://doi.org/10.3390/ma16051837 - 23 Feb 2023

Cited by 4 | Viewed by 1629

Abstract

Supplementary cementitious materials (SCMs) are commonly used in the manufacture of commercial cements with lower clinker content and carbon footprints, enabling environmental and performance improvements. The present article evaluated a ternary cement combining 23% calcined clay (CC) and 2% nanosilica (NS) to replace [...] Read more.

Supplementary cementitious materials (SCMs) are commonly used in the manufacture of commercial cements with lower clinker content and carbon footprints, enabling environmental and performance improvements. The present article evaluated a ternary cement combining 23% calcined clay (CC) and 2% nanosilica (NS) to replace 25% of the Ordinary Portland Cement (OPC) content. For this purpose, a series of tests were performed, such as compressive strength, isothermal calorimetry, thermogravimetry (TG/DTG), X-ray diffraction (XDR), and mercury intrusion porosimetry (MIP). The ternary cement studied, 23CC2NS, presents a very high surface area, which influences hydration kinetics by accelerating silicate formation and causes an undersulfated condition. The pozzolanic reaction is potentialized by the synergy between the CC and NS, resulting in a lower portlandite content at 28 days in the 23CC2NS paste (6%) compared with the 25CC paste (12%) and 2NS paste (13%). A significant reduction in total porosity and conversion of macropores in mesopores was observed. For example, 70% of pores in OPC paste were macropores that were converted in the 23CC2NS paste into mesopores and gel pores. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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15 pages, 14248 KiB  

Open AccessArticle

Experimental and Numerical Investigation on the Triaxial Compressive Behavior of Steamed Recycled Aggregate Concrete

by Yuzhi Chen, Yingjie Ning, Xudong Chen, Weihong Xuan and Xiangyi Zhu

Buildings 2023, 13(2), 334; https://doi.org/10.3390/buildings13020334 - 23 Jan 2023

Cited by 1 | Viewed by 1148

Abstract

The use of recycled aggregates to produce precast concrete products is conductive to the green development of construction industrialization. This paper aimed to study the effects of curing regimes and confining pressures on the triaxial compression behavior of recycled aggregate concrete (RAC). Triaxial [...] Read more.

The use of recycled aggregates to produce precast concrete products is conductive to the green development of construction industrialization. This paper aimed to study the effects of curing regimes and confining pressures on the triaxial compression behavior of recycled aggregate concrete (RAC). Triaxial compression tests were carried out on RAC under different curing regimes (standard curing, 60 °C—12 h and 80 °C—9 h), and the designed confining pressures were 0 MPa, 2.5 MPa, 5 MPa, and 10 MPa. The results show that the increase of confining pressure limits the expansion of cracks, causing the failure mode to change from vertical splitting to oblique shearing, and the triaxial compressive strength is doubled at most. Compared with standard curing, steam curing significantly weakened the triaxial compressive strength of RAC, which was related to the reduction of RAC cohesion, and the cohesion of RAC steam cured at 80 °C was reduced by 30%. The triaxial compression failure of RAC closely follows the Mohr–Coulomb criterion. Based on the discrete element method and test results, an RAC triaxial compression numerical model considering the shape of the actual coarse aggregate was established, and the propagation of cracks was discussed at the mesoscopic level. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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17 pages, 5999 KiB  

Open AccessArticle

The Influence of Alkali Content on the Hydration of the Slag-Based Geopolymer: Relationships between Resistivity, Setting, and Strength Development

by Yuan Fang, Kunde Zhuang, Dapeng Zheng and Weitao Guo

Polymers 2023, 15(3), 518; https://doi.org/10.3390/polym15030518 - 18 Jan 2023

Cited by 2 | Viewed by 1416

Abstract

This study investigated the influence of alkali content on the early-age hydration process of slag-based geopolymer and the feasibility of non-destructive resistivity. Results showed that there existed a threshold of alkali content in adjusting the early-age hydration. Initially, increasing the alkali content tended [...] Read more.

This study investigated the influence of alkali content on the early-age hydration process of slag-based geopolymer and the feasibility of non-destructive resistivity. Results showed that there existed a threshold of alkali content in adjusting the early-age hydration. Initially, increasing the alkali content tended to accelerate the dissolution period (detected by resistivity and heat release rate) and resulted in a denser microstructure (detected by TEM). When the alkali content surpassed 6 wt%, the increasing alkali content mitigated the structural development of a slag-based geopolymer, as it lowered the liquid water content and caused local precipitation, which trapped the early-age ions transmission and, therefore, the later-age mechanical development was inhibited. It was proven that the resistivity acted as a linkage among the reaction degree, workability, and strength development. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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12 pages, 3988 KiB  

Open AccessArticle

Shrinkage of Micro-Synthetic Fiber-Reinforced Mortar

by Endah Safitri, Ridan Adi Kusworo and Stefanus Adi Kristiawan

Infrastructures 2023, 8(1), 7; https://doi.org/10.3390/infrastructures8010007 - 31 Dec 2022

Cited by 3 | Viewed by 2378

Abstract

Repair materials have been developed in this research by adding micro-synthetic fibers in cement-based mortar. In addition, accelerator is incorporated in the mortar to obtain high early strength of the repair materials. Their shrinkage behavior is of interest. This study aims to determine [...] Read more.

Repair materials have been developed in this research by adding micro-synthetic fibers in cement-based mortar. In addition, accelerator is incorporated in the mortar to obtain high early strength of the repair materials. Their shrinkage behavior is of interest. This study aims to determine the shrinkage of the micro-synthetic fiber-reinforced mortar and propose models to reflect their shrinkage behavior. The results show that rapid developments of shrinkage are observed at an early age where the 3-day shrinkage already attains about 40–50% of the 84-day shrinkage value. Moreover, after 14 days of age the shrinkage curves tend to approach the asymptotic value. The ACI 209.2R-08 and CEB-MC 90-99 models do not reflect the shape of the shrinkage curves of the micro-synthetic fiber-reinforced mortar. Therefore, this research proposes a modified ACI 209.2R-08 and CEB-MC 90-99 that can describe the shrinkage behavior of the micro-synthetic fiber-reinforced mortar. The accuracy of the modified models has been confirmed quantitatively using the method of best fit line, residual analysis, and coefficient of error. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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16 pages, 4049 KiB  

Open AccessArticle

Mechanical Feasibility of Asphalt Materials for Pavement Solar Collectors: Small-Scale Laboratory Characterization

by Marco Pasetto, Andrea Baliello, Giovanni Giacomello and Emiliano Pasquini

Appl. Sci. 2023, 13(1), 358; https://doi.org/10.3390/app13010358 - 27 Dec 2022

Cited by 6 | Viewed by 1161

Abstract

Rutting (i.e., depressions along the wheel path) is a distress exhibited by flexible asphalt pavements at high in-service temperatures negatively affecting ride comfort and safety. In this regard, the fine asphalt mortar (i.e., bitumen filler and fine sand) plays a key role in [...] Read more.

Rutting (i.e., depressions along the wheel path) is a distress exhibited by flexible asphalt pavements at high in-service temperatures negatively affecting ride comfort and safety. In this regard, the fine asphalt mortar (i.e., bitumen filler and fine sand) plays a key role in the rutting potential of the asphalt mixtures. Given this background, this manuscript presents a small-scale laboratory experimentation aimed at assessing the rutting-related performance of a plain bitumen combined with natural (limestone) or manufactured (steel slag) fine aggregates (size up to 0.18 mm) through advanced experimental and theoretical approaches. Specific rheological tests through dynamic shear were carried out to achieve this goal. The investigated asphalt blends came from a wider research project focused on the implementation of a pavement solar collector (a road system to harvest the solar energy irradiating the pavement). In particular, the present paper aimed at verifying the mechanical suitability of the produced asphalt mixes with respect to permanent deformation resistance. Such a small-scale investigation mainly showed that the previously selected constituent materials did not imply criticisms in terms of rutting response. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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19 pages, 4109 KiB  

Open AccessArticle

Vegetal-FRCM Failure under Partial Interaction Mechanism

by Virginia Mendizabal, Borja Martínez, Luis Mercedes, Ernest Bernat-Maso and Lluis Gil

Appl. Sci. 2022, 12(24), 12964; https://doi.org/10.3390/app122412964 - 16 Dec 2022

Cited by 4 | Viewed by 1324

Abstract

FRCM is a strengthening system based on composite material made of a cementitious matrix and fabrics. This strengthening system has been studied and researched, obtaining analytical predictive models where it is common to assume full composite action between components. Through using non-typical materials [...] Read more.

FRCM is a strengthening system based on composite material made of a cementitious matrix and fabrics. This strengthening system has been studied and researched, obtaining analytical predictive models where it is common to assume full composite action between components. Through using non-typical materials for these composites, it has been seen that, in some cases, the previous assumption cannot be taken. In this situation, traditional analytical models such as ACK or tri-linear ones do not offer a reasonable prediction. This work researches the behavior of synthetic and naturally coated vegetal-FRCM with partial interaction through the characterization of the materials through tensile tests. Yarns, meshes and different FRCM coupons were manufactured and mechanically tested using different types of coatings and fabrics. The use of colophony and Arabic gum as natural coatings provided similar mechanical properties to the cotton and hemp yarns and meshes conformed. Partial interaction was found when using epoxy as a natural resin to coat the reinforcement while maintaining the mechanical properties in the same order of magnitude. A new two-stage model is proposed to fit stress–strain mechanical test, and it is reliable and accurate for cotton specimens. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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14 pages, 7794 KiB  

Open AccessArticle

Development and Application of Similar Materials for Foundation Pit Excavation Model Test of Metro Station

by Zeyao Zhang, Yang Gao, Xinyu Zheng, Jiarui Cao and Yong Chen

Appl. Sci. 2022, 12(24), 12880; https://doi.org/10.3390/app122412880 - 15 Dec 2022

Viewed by 1996

Abstract

Geomechanical model tests provide an intuitive and convenient method for observing physical phenomenon due to their easy implementation compared to in situ tests and prototype tests. The success of model tests depends heavily on the appropriate selection of model materials and proportions. Therefore, [...] Read more.

Geomechanical model tests provide an intuitive and convenient method for observing physical phenomenon due to their easy implementation compared to in situ tests and prototype tests. The success of model tests depends heavily on the appropriate selection of model materials and proportions. Therefore, a new similar material is developed by utilizing the orthogonal experimental design method to conduct a series of proportioning tests. The new material is mixed with barite powder, iron ore powder, quartz sand, liquid paraffin, rosin, gypsum powder, and water. The physical and mechanical properties are studied through uniaxial compressive tests, Brazilian splitting tests, and direct shear tests. The influences of various raw material factors on the parameters of the similar material are systematically studied through range analysis. The results demonstrate that the mechanical parameters of similar materials have wide variation ranges; the adjustment range is 42.0–279.0 MPa for the elastic modulus, 0.37–5.37 MPa for the uniaxial compressive strength and 2.23–2.65 g/cm³ for the density. The new similar material has illustrated advantages in terms of performance stability, low price, and convenient production, which can simulate the similar relationship with different geomechanical model tests. The similar material is applied to a 3D geomechanical model test of the foundation pit excavation of Shenzhen metro station, which proves that the similar material can realistically reflect the change of earth pressure in the excavation process. With the deepening of excavation, the earth pressure curve shows significant fluctuations, and as the retaining structure is displaced, the parts with large earth pressure changes should be strengthened. The research methods and results can provide reference for further geological engineering research. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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13 pages, 2607 KiB  

Open AccessArticle

Quantification of Magnesia Dissolution in Silicate Melts and Diffusivity Determination Using Rotating Finger Test

by Burhanuddin, Harald Harmuth and Sandra Vollmann

Appl. Sci. 2022, 12(24), 12791; https://doi.org/10.3390/app122412791 - 13 Dec 2022

Cited by 4 | Viewed by 1085

Abstract

Refractories exposed to corrosive melts at high temperatures experience wear due to dissolution. The presented work deals with the dynamic corrosion of magnesia fine ceramics in a CaO–Al₂O₃–SiO₂–MgO silicate slag with a CaO/SiO₂ weight ratio of [...] Read more.

Refractories exposed to corrosive melts at high temperatures experience wear due to dissolution. The presented work deals with the dynamic corrosion of magnesia fine ceramics in a CaO–Al₂O₃–SiO₂–MgO silicate slag with a CaO/SiO₂ weight ratio of 0.65. Finger tests at 200 rpm at three different temperatures, 1450, 1500, and 1550 °C, were performed. A contemporary rotary finger test (RFT) device with in-situ wear profile measurement using a laser device was used. The precise dimension measurements with high-resolution facilitate the determination of total mass flux densities, which allow for determination of effective binary diffusivities. Thereby, two methods based on Sherwood relations were applied. The comparison shows the benefit to better consider deviations from pure cylinder shape. The use of contemporary RFT devices and magnesia fine ceramics allows reliable determination of the effective binary diffusivity. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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16 pages, 7170 KiB  

Open AccessArticle

Optimizing the Composition Design of Cement-Based Expanded-Polystyrene (EPS) Exterior Wall Based on Thermal Insulation and Flame Retardance

by Jicun Shi, Lei Zhao, Yao Zhang, Hongxing Han, Lihuang Zhou and Chenxi Wang

Polymers 2022, 14(23), 5229; https://doi.org/10.3390/polym14235229 - 1 Dec 2022

Cited by 5 | Viewed by 4196

Abstract

The use of thermal insulated decorative panel materials with low thermal conductivity and high flame retardance is a key step toward energy-saving buildings. However, traditional thermal insulation materials are always highly conductive and inflammable, which restricts their application for new buildings. This study [...] Read more.

The use of thermal insulated decorative panel materials with low thermal conductivity and high flame retardance is a key step toward energy-saving buildings. However, traditional thermal insulation materials are always highly conductive and inflammable, which restricts their application for new buildings. This study aims to prepare the non-combustible, cement-based EPS mixtures with thermal conductivity lower than 0.045 and density less than 140 kg/m³ and characterize it with mechanical, thermal, and flame retardant properties. The effect of particle size, Silica coated and content of EPS on the physical, mechanical, thermal, and combustion performance are conducted in this paper. The comprehensive indoor tests including density, water absorbing, softening coefficient, compressive strength, tensile strength, moisture susceptibility, thermal conductivity, and scanning electron microscopy (SEM) along with combustion performance are reported to evaluate the effects of several variables on the investigated cement-based nonflammable EPS (CEPS)mixtures. The results show that small and gradation EPS particles significantly improve the comprehensive performance of mixtures. In addition, Silica coated ESP significantly improve the flame retardance of mixtures while reduce the mechanical characteristics slightly. These results contribute to the selection of appropriate materials to enhance the thermal insulation, flame retardance and mechanical properties of CEPS. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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26 pages, 7652 KiB  

Open AccessArticle

Macroscopic Properties and Pore Structure Fractal Characteristics of Alkali-Activated Metakaolin–Slag Composite Cementitious Materials

by Jianghuai Zhan, Bo Fu and Zhenyun Cheng

Polymers 2022, 14(23), 5217; https://doi.org/10.3390/polym14235217 - 30 Nov 2022

Cited by 7 | Viewed by 1475

Abstract

To investigate the effects of slag and Na₂O content on the macroscopic properties and pore structure characteristics of alkali-activated metakaolin–slag (AAMS) composite cementitious materials, this study used X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM-EDS), and mercury-pressure [...] Read more.

To investigate the effects of slag and Na₂O content on the macroscopic properties and pore structure characteristics of alkali-activated metakaolin–slag (AAMS) composite cementitious materials, this study used X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM-EDS), and mercury-pressure (MIP) tests for characterization and analyzed the hydration product compositions, microstructures, and pore structure characteristics of AAMS composite cementitious materials. The relationships between the fractal dimension and the pore structure parameters, compressive strengths, and drying shrinkage rates of AAMS composite cementitious materials were investigated with the thermodynamic fractal model. The results showed that at the age of 28 d, the compressive strength and drying shrinkage of the AAMS composite binder increased by 20.57% and 215.11%, respectively, when the slag content increased from 0 to 50%. When the Na₂O content increased from 8% to 12%, the compressive strength and drying shrinkage of the AAMS composite increased by 24.37% and 129.40%, respectively. The compressive strengths of AAMS composite cementitious materials increased with increasing slag content and Na₂O content, but the drying shrinkage of the system increased, and the volume stability worsened. Microscopic analyses showed that with increases in the slag and Na₂O contents, the hydration products of AAMS composite cementitious materials increased, and C-A-S-H and N-A-S-H filled each other so that the internal structures of AAMS composite cementitious materials were denser, and the porosities were significantly reduced. By comparing and analyzing the Menger sponge model and the fractal model based on the thermodynamic relationships, it was found that the fractal model based on the thermodynamic relationship better reflected the pore size distribution over the whole pore size determination range, and the correlation coefficients R² were above 0.99, indicating that the fractal dimension calculated by the fractal model based on the thermodynamic relationship provided a comprehensive evaluation index for the pore structure characteristics of AAMS composite cementitious materials, and the fractal dimension correlated well with the pore structure parameters, compressive strengths, and drying shrinkage rates of cementitious materials. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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12 pages, 3695 KiB  

Open AccessArticle

Freezing and Thawing Processes of Highways in Kazakhstan

by Bagdat Teltayev, Cesare Oliviero Rossi, Koblanbek Aitbayev, Elena Suppes, Aidos Yelshibayev and Assel Nugmanova

Appl. Sci. 2022, 12(23), 11938; https://doi.org/10.3390/app122311938 - 23 Nov 2022

Cited by 3 | Viewed by 1648

Abstract

This paper presents the results of an experimental study of freezing and thawing patterns of highways in Kazakhstan. Special sensors measure temperature and moisture change every hour in automatic mode. The purpose of this work is to develop a methodology for determining the [...] Read more.

This paper presents the results of an experimental study of freezing and thawing patterns of highways in Kazakhstan. Special sensors measure temperature and moisture change every hour in automatic mode. The purpose of this work is to develop a methodology for determining the depth of freezing of subgrade soils of roads of Kazakhstan, and the task is to establish the pattern of cold temperature change (temperature “0 °C”) through certain points (sensors) at any time. In the upper part of the pavement (up to 30–40 cm), the temperature changes in annual and daily cycles. As the depth increases, the daily temperature fluctuations disappear, leaving only the annual fluctuation. At a depth of 180 cm and below, temperature fluctuations occur only in the annual cycle. The freezing rate varied from 14 cm/day to 0.33 cm/day. The maximum freezing depth was 227 cm. The descending branch of thawing occurs almost uniformly, with an average rate of 6.25 cm/day to a depth of 220 cm; the average rate of the ascending branch of thawing is 0.9 cm/day. Asphalt–concrete layers of the pavement and the upper part of the subgrade were in a frozen state for 151 and 166 days, respectively. In the subgrade at the beginning and end of the cold period, there are abrupt changes in moisture, which are explained by phase transitions of the second order: the transition from the liquid state to the solid (ice) at the beginning of the cold period and the transition of moisture from the solid state to liquid at the end of the cold period. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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13 pages, 5062 KiB  

Open AccessArticle

Novel Slow-Release Defoamers for Concrete Using Porous Nanoparticles as Carriers

by Guangcheng Shan, Min Qiao, Jian Chen, Nanxiao Gao, Fei Shen and Qianping Ran

Materials 2022, 15(22), 7993; https://doi.org/10.3390/ma15227993 - 12 Nov 2022

Cited by 4 | Viewed by 1540

Abstract

Excess large and unstable air bubbles can reduce the compressive strength of hardened concrete, and traditional defoamers always fail because of adsorption and encapsulation on cement with the progress of cement hydration in later stages. It is necessary to develop a novel defoamer [...] Read more.

Excess large and unstable air bubbles can reduce the compressive strength of hardened concrete, and traditional defoamers always fail because of adsorption and encapsulation on cement with the progress of cement hydration in later stages. It is necessary to develop a novel defoamer that shows a sustained defoaming ability in fresh concrete. A novel slow-release defoamer for concrete using porous nanoparticles as carriers is reported for the first time. The porous nanoparticles/polyether defoamer composite (SiO₂-Def) was prepared via sol-gel method. SiO₂-Def is a spherical composite nanoparticle with a size range of 160–200 nm and a uniform pore size distribution. SiO₂-Def shows a high load rate of about 16.4% and an excellent release under an alkali and salt environment. It has a weak initial defoaming ability but shows a sustained defoaming ability with time, so that it can avoid the failures of defoamers and eliminate harmful bubbles entrained during the processes of pumping and transportation. Moreover, SiO₂-Def produced a higher compressive strength of the hardened cement mortars. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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14 pages, 13297 KiB  

Open AccessArticle

Long-Term Deformations and Mechanical Properties of Fine Recycled Aggregate Earth Concrete

by Hassan Fardoun, Jacqueline Saliba, Jean-Luc Coureau, Alain Cointe and Nadia Saiyouri

Appl. Sci. 2022, 12(22), 11489; https://doi.org/10.3390/app122211489 - 12 Nov 2022

Cited by 5 | Viewed by 1717

Abstract

Earth-based materials are currently receiving high attention, as they are considered as sustainable. In addition, the reuse of waste materials and more particularly recycled aggregates can boost circular economy while reducing landfilling and mineral resource depletion. Incorporating recycled aggregates in earth concrete can [...] Read more.

Earth-based materials are currently receiving high attention, as they are considered as sustainable. In addition, the reuse of waste materials and more particularly recycled aggregates can boost circular economy while reducing landfilling and mineral resource depletion. Incorporating recycled aggregates in earth concrete can be an innovative way to valorize them. However, investigations are required concerning their long-term behavior. Such an aspect is more important when fine recycled aggregates are considered. In this paper, the vulnerability to long term deformations of natural sand (NS) and recycled sand (RS) earth concrete mixtures is examined under real exposure conditions. Autogenous shrinkage, drying shrinkage, basic creep and drying creep of the different mixtures were monitored for a period of two months. Specimens were then subjected to compressive tests in order to evaluate their residual strength. Furthermore, the destructive tests were monitored in parallel with the acoustic emission (AE) technique. The results show an increase in the rate of drying creep and shrinkage for RS earth concrete mixtures. In addition, NS and RS earth concrete mixtures subjected to drying, with and without loading, reported a strength development in comparison to the reference mixtures. However, the Young’s modulus reported its lowest value for drying shrinkage of both mixtures. Regarding the AE technique, the distribution of its activity reflected the higher rate of damage of dried specimens in the pre-peak region. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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9 pages, 2749 KiB  

Open AccessArticle

The Analysis of Materials Strength Used in the Construction of the Flexible Underwater Bell—Batychron

by Grzegorz Rutkowski, Paweł Kołakowski and Katarzyna Panasiuk

Materials 2022, 15(21), 7768; https://doi.org/10.3390/ma15217768 - 3 Nov 2022

Viewed by 1349

Abstract

Batychron is a flexible underwater bell patented by the Gdynia Maritime University as a device used in hydro-technics engineering for underwater transport and diving while maintaining the safety of human life. This study aims to present the methods and results of strength tests [...] Read more.

Batychron is a flexible underwater bell patented by the Gdynia Maritime University as a device used in hydro-technics engineering for underwater transport and diving while maintaining the safety of human life. This study aims to present the methods and results of strength tests and the conducted analysis of the selection of the most appropriate method of joining thermoplastic polyurethane film (TPU) and polypropylene belts for underwater use to obtain a device with a specific buoyancy force. A universal testing machine with a hydraulic drive was used for the tests. Various methods of joining polypropylene belts were tested to select the most favourable in terms of strength properties. For this purpose, two types of materials were selected: the TE324 polyester belt and the TS501_50 style belt. Various connection methods have been used: without seams; zig-zag stitch, straight cross; cross stitch, straight longitudinal; cross stitch, straight transverse, in order to select a joint with the highest strength parameters. In addition, the tensile strength of individual types of belts was tested. The methods of joining the TPU film were verified. The obtained results allowed us to determine that the strongest bond of TE324 material is a straight, longitudinal cross stitch. This is related to the load distribution in the belts tested in laboratory conditions, but also reflected in their practical application. Thanks to the results obtained, it was possible to select the optimal methods of joining (connection) and the construction of Batychron. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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48 pages, 2980 KiB  

Open AccessReview

A Comprehensive Overview on Corrosion in RCC and Its Prevention Using Various Green Corrosion Inhibitors

by Junaid Ahmed E S and G. Mohan Ganesh

Buildings 2022, 12(10), 1682; https://doi.org/10.3390/buildings12101682 - 13 Oct 2022

Cited by 18 | Viewed by 4890

Abstract

Reinforced cement concrete (RCC) is a versatile material that deteriorates over time due to corrosion when exposed to any surrounding aggressive environment. In order to avoid this ramification, many researchers have carried out different work to find the most feasible way to reduce [...] Read more.

Reinforced cement concrete (RCC) is a versatile material that deteriorates over time due to corrosion when exposed to any surrounding aggressive environment. In order to avoid this ramification, many researchers have carried out different work to find the most feasible way to reduce corrosion. To tackle this at the initial stage itself, one such convenient method is through the application of inhibitors. These inhibitors have most applications in their use as an admixture. This review paper mainly focuses on the inhibitor and its types, the drawbacks of inorganic, commercial organic, and hybrid inhibitors, and application to RCC, and also provides detailed information on green corrosion inhibitors (GCI). In recent years, widespread attention has been paid towards the utilization of different natural plant components/parts in concrete structures. This review paper consolidates the work done by various researchers using different GCIs with the main focus on plant extracts as an additive to concrete or RCC specimens which will be significant to sustainable progress in the field of corrosion. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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11 pages, 3759 KiB  

Open AccessArticle

The Effect of Seawater on Mortar Matrix Coated with Hybrid Nano-Silica-Modified Surface Protection Materials

by Yue Gu, Ruyan Fan, Kailun Xia, Kai Lyu, Zhenhua Wei and Mingzhi Guo

Polymers 2022, 14(19), 4080; https://doi.org/10.3390/polym14194080 - 29 Sep 2022

Viewed by 1531

Abstract

Surface treatment technology is an effective method to reinforce the durability of concrete. In this study, cement-based materials containing industrial solid wastes were modified by hybrid nano-silica (HN), then applied as a novel surface protection material (SPM-HN). The effect of SPM-HN on surface [...] Read more.

Surface treatment technology is an effective method to reinforce the durability of concrete. In this study, cement-based materials containing industrial solid wastes were modified by hybrid nano-silica (HN), then applied as a novel surface protection material (SPM-HN). The effect of SPM-HN on surface hardness of mortar matrix exposed to seawater was investigated. Further, the microstructure was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and mercury intrusion porosimetry (MIP). The results show SPM-HN could significantly enhance the surface hardness of matrix in seawater curing, and the rebound number is increased by 94%.The microstructure analysis demonstrates that the incorporation of HN inhibits the formation of ettringite, thaumasite, and Friedel’s salt. In addition, thermodynamic modeling shows the incorporation of hybrid nano-silica could generate more C-S-H, and decrease the maximum volume of Friedel’s salt when SPM is exposed to seawater. This research indicates SPM-HN can be applied as a concrete protective layer in the marine environment. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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18 pages, 2522 KiB  

Open AccessArticle

Study on Early Shrinkage and Mechanical Properties of Concrete with Various Cementitious Materials

by Peng Wang, Ming Xie and Lei Liu

Buildings 2022, 12(10), 1543; https://doi.org/10.3390/buildings12101543 - 27 Sep 2022

Cited by 2 | Viewed by 2014

Abstract

Due to the rapid development of industrialization, the recycling and utilization of industrial by-products have received extensive attention. In this paper, binary, ternary, and quaternary composite cementitious materials were prepared using steel slag, blast furnace slag, and fly ash, and the effects of [...] Read more.

Due to the rapid development of industrialization, the recycling and utilization of industrial by-products have received extensive attention. In this paper, binary, ternary, and quaternary composite cementitious materials were prepared using steel slag, blast furnace slag, and fly ash, and the effects of different cementitious materials on concrete properties were explored. A variety of solid wastes were mixed, and batches of concrete with high mechanical properties and durability were prepared by adjusting the type and amount of cementitious materials used. A total of 15 batches of concrete were prepared and tested for compressive strength, splitting tensile strength, axial compressive strength, elastic modulus, and drying shrinkage. The test results show that a fly ash, blast furnace slag powder, and steel slag powder ratio of 1:1:2 produces a concrete with the best mechanical properties. Among them, the cube compressive strength can reach 62.9 MPa, the splitting tensile strength is 5.7 MPa, the axial compressive strength and elastic modulus are increased, the early shrinkage is small, the growth rate is slow, and the 28d concrete shrinkage rate is 4.87 × 10⁻⁴. This new type of green mixed concrete can not only control production costs, but can also reduce environmental impact and decrease carbon dioxide emissions. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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10 pages, 848 KiB  

Open AccessArticle

Application of the Hot Wire Method to Measure the Thermal Conductivity Coefficient of a Gypsum Composite

by Krzysztof Powała, Andrzej Obraniak, Dariusz Heim and Andrzej Mrowiec

Materials 2022, 15(19), 6564; https://doi.org/10.3390/ma15196564 - 22 Sep 2022

Cited by 2 | Viewed by 1566

Abstract

Currently, there is much discussion about modern technologies and solutions in construction. There are new solutions that save electricity or heat, usually in buildings additionally equipped with intelligent management systems. High hopes are placed on building materials. Every investment begins with them. The [...] Read more.

Currently, there is much discussion about modern technologies and solutions in construction. There are new solutions that save electricity or heat, usually in buildings additionally equipped with intelligent management systems. High hopes are placed on building materials. Every investment begins with them. The basic building materials include materials such as cement, bricks, hollow bricks or plasterboard, and their modification and the use of admixtures ensure the greatest changes in the parameters of the building. This article focuses on the preparation and testing of gypsum mortar consisting of gypsum, phase change material and polymer. The idea was to replace the proven method of adding microencapsulated phase change material by direct binding. This article presents the study of thermal conductivity by the hot wire method. Using this method, tests of temperature changes during plaster hardening were also carried out. Compressive strength tests were also carried out on the 14th, 21st, 28th, 35th and 105th day from the date of making the samples. For each of these tests, three types of samples with different polymer content were used. After a series of tests, the best results were obtained by a series of samples with 0.1% polymer. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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17 pages, 2801 KiB  

Open AccessArticle

Predicting Dynamic Properties of Asphalt Mastic Considering Asphalt–Filler Interaction Based on 2S2P1D Model

by Xiaoyan Ma, Xingyu Zhang, Junpeng Hou, Shanglin Song, Huaxin Chen and Dongliang Kuang

Materials 2022, 15(16), 5688; https://doi.org/10.3390/ma15165688 - 18 Aug 2022

Cited by 3 | Viewed by 1501

Abstract

The relationship between the various phases of asphalt materials, from asphalt binder to mastic and mixture, has received great attention over the years, with efforts being made to establish linkages among these phases. Many methods for predicting the rheology properties of asphalt mastics [...] Read more.

The relationship between the various phases of asphalt materials, from asphalt binder to mastic and mixture, has received great attention over the years, with efforts being made to establish linkages among these phases. Many methods for predicting the rheology properties of asphalt mastics from those of asphalt and filler volume fractions exist. However, most prediction methods are based on an empirical formula and on the micromechanical model. Very few research studies focus on the constitutive model. In addition, relatively little research has explored the influence of asphalt–filler interaction on mastic’s rheology properties, which is believed to be an important factor. In this study, the 2S2P1D (two springs, two parabolic elements, and one dashpot) model was applied to link the behavior of asphalt binder, filler volume fraction, asphalt–filler interaction and asphalt mastic. First, the interaction between asphalt and filler was evaluated, and the interaction parameter C of the Palierne model was used as an assessment indicator to calculate the effective filler volume fraction of asphalt mastic. Then, the relation between the 2S2P1D model parameters of asphalt mastic and those of asphalt binder and the effective filler volume fraction was analyzed. Finally, a simple relationship associating the 2S2P1D model parameters $h$, $\log ({\tau }_0)$ of mastic and that of asphalt binder and the effective filler volume fraction was developed. The proposed expression was validated, and the result showed that it was an efficient model for the shear complex modulus prediction of virgin asphalt mastic. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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11 pages, 5973 KiB  

Open AccessArticle

Ultraviolet-Assisted Modified Delignified Wood with High Transparency

by Xiaoli Chen, Shangjie Ge-Zhang, Yu Han, Hong Yang, Wenao Ou-Yang, Haotong Zhu, Junyi Hao and Jinxin Wang

Appl. Sci. 2022, 12(15), 7406; https://doi.org/10.3390/app12157406 - 23 Jul 2022

Cited by 7 | Viewed by 2607

Abstract

The substrate of solar cells with high haze, transparent, flexible, green and low coatings will be needed in the future. This paper reports a method for ultraviolet-assisted delignification of wood in an alkaline solution environment to improve the transmittance of “transparent wood”. Scanning [...] Read more.

The substrate of solar cells with high haze, transparent, flexible, green and low coatings will be needed in the future. This paper reports a method for ultraviolet-assisted delignification of wood in an alkaline solution environment to improve the transmittance of “transparent wood”. Scanning electron microscope (SEM), X-ray diffraction image (XRD), Fourier transform infrared (FTIR) spectroscopy and transmittance-haze and chemical composition analysis were used to explore the mechanisms underlying the effect of ultraviolet-assisted lignin modification on the optical properties of “transparent wood”. The results show that UV-assisted delignification accelerates the rate of removal of lignin and chromogenic groups, which in turn improves the optical properties of the “transparent wood”, with UV-assisted lignin modification for 2 h increasing the light transmission of the “transparent wood” by 20%. UV-assisted delignification for 4 h and impregnation resulted in “transparent wood” with a transparency of 71% and a haze of 90%. This report provides a rapid and easy method to prepare high-quality “transparent wood”. The “transparent wood” with high transmittance and high haze is a potential candidate for transparent solar substrates. Meanwhile, this method is enlightening for high quality, fast and green preparation of other derived functional materials based on lignin wood. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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22 pages, 9464 KiB  

Open AccessArticle

Study on Static and Fatigue Behaviors of Steel-UHPFRC Composite Deck Structure

by Jun Luo, Chenzi Huai, Xudong Shao, Jun Zhao and Ling Wang

Polymers 2022, 14(14), 2796; https://doi.org/10.3390/polym14142796 - 8 Jul 2022

Cited by 3 | Viewed by 1631

Abstract

Ultra-high-performance fiber-reinforced cementitious composite (UHPFRC) is used in orthotropic steel deck (OSD) to form a lightweight composite deck structure (LWCD), which is expected to solve the problems of fatigue cracking of traditional steel deck and pavement damage. This paper aims to study the [...] Read more.

Ultra-high-performance fiber-reinforced cementitious composite (UHPFRC) is used in orthotropic steel deck (OSD) to form a lightweight composite deck structure (LWCD), which is expected to solve the problems of fatigue cracking of traditional steel deck and pavement damage. This paper aims to study the influence of key design parameters on longitudinal bending and transverse fatigue performance, as well as the ultimate bearing capacity calculation theory of the LWCD. A local finite-element (FE) model was built to evaluate the vehicle-induced stress ranges of six typical fatigue-prone details. In total, eight negative bending tests on steel-UHPFRC composite beams and one fatigue test on a steel-UHPFRC composite plate were conducted to investigate the longitudinal bending performance and the transverse flexural fatigue behavior of the LWCD, respectively. The results show that adding a 60-mm UHPFRC layer can significantly reduce the stress amplitude of six typical fatigue details by 44.8% to 90%. The failure mode of the longitudinal bending tests is the U-rib buckle and all UHPFRC layers exhibit multiple cracking behaviors when the specimens failed. The longitudinal cracking stresses of the specimens are between 20.0 MPa to 27.3 MPa. The reinforcement ratio and cover thickness have a great influence on the cracking stress. While the ultimate bearing capacity of specimens with different parameters has little difference. The calculation method of the ultimate bearing capacity of a steel-UHPFRC composite structure is proposed. When the strain at the bottom of the u-rib is taken as 1.2 times the design yield strain, the calculated results are in good agreement with the experimental results. No fatigue failure was observed after 66.12 million fatigue cycles under the design load, highlighting the favorable fatigue resistance of the proposed LWCD. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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11 pages, 6120 KiB  

Open AccessArticle

Influence of Paste Strength on the Strength of Expanded Polystyrene (EPS) Concrete with Different Densities

by Diyang He, Wukui Zheng, Zili Chen, Yongle Qi, Dawang Zhang and Hui Li

Polymers 2022, 14(13), 2529; https://doi.org/10.3390/polym14132529 - 21 Jun 2022

Cited by 4 | Viewed by 1812

Abstract

Concrete in which EPS (expanded polystyrene) particles partially or completely replace concrete aggregates is called EPS concrete. Compared to traditional concrete, EPS concrete has a controllable low density and good thermal-insulation performance, which make it promising for prospective applications. At present, research on [...] Read more.

Concrete in which EPS (expanded polystyrene) particles partially or completely replace concrete aggregates is called EPS concrete. Compared to traditional concrete, EPS concrete has a controllable low density and good thermal-insulation performance, which make it promising for prospective applications. At present, research on EPS concrete mostly focuses on increasing its strength and EPS surface modifications. Few researchers have studied the influence of cementitious material strength and EPS-concrete density on the strength of EPS concrete. In this research, cement was used as the main material, and fly ash, silica fumes, and blast furnace slag were selected as admixtures. By changing the mixing proportions of the admixtures, the basic properties, such as the paste strength, change. Based on the mix proportions of the above different raw materials, EPS concrete with different density levels was prepared to explore the influence of the density of EPS concrete and the strength of cementitious materials on the strength of EPS concrete. The influence of the slurry strength on EPS-concrete strength was weaker than that of the density of EPS concrete. When the strength range of the cementitious materials is 35.7~70.5 MPa, the compressive strength range of 1000 kg/m³, 1200 kg/m³, and 1400 kg/m³ EPS concrete is 8.8~17.6 MPa, 11.4~18.0 MPa, and 15.7~26.6 MPa, respectively. Based on the experiments, the fitting equation to determine the EPS-concrete strength–EPS-concrete density–cementitious material strength is z = 69.00087 + 0.0244x − 0.1746y − 0.00189x² + 0.0000504706y² + 0.00028401xy. Additionally, a strength-increasing design method for EPS concrete with different densities prepared by conventional Portland cement is clarified. This study can guide the preparation of EPS concrete. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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13 pages, 4114 KiB  

Open AccessArticle

Properties Evolution of Some Hydraulic Mortars Incorporating Graphene Oxides

by Popa Dorin, Prodan Doina, Varvara Simona, Popa Maria, Cuc Stanca, Sarosi Codruta, Moldovan Marioara, Ivan Raluca and Ene Razvan

Buildings 2022, 12(6), 864; https://doi.org/10.3390/buildings12060864 - 20 Jun 2022

Cited by 4 | Viewed by 1927

Abstract

In this experimental study, the mechanical and adhesion properties of several hydraulic lime mortars incorporating graphene oxide (GO)-based nanomaterials were evaluated. Four different composite mortar samples were prepared by adding different percentages of GO-based powders (functionalized), i.e., 1 wt.% GO, 5 wt.% GO, [...] Read more.

In this experimental study, the mechanical and adhesion properties of several hydraulic lime mortars incorporating graphene oxide (GO)-based nanomaterials were evaluated. Four different composite mortar samples were prepared by adding different percentages of GO-based powders (functionalized), i.e., 1 wt.% GO, 5 wt.% GO, 5wt.% GO-Ag-GO-Fly ash, and 5 wt.% GO-ZnO-GO-TiO₂ into the reference mortar sample. The mortar specimens were analyzed through mechanical tests, FT-IR, and SEM. The behavior of selected mortars exposed to chemical attacks was also investigated. The results indicate that the addition of the functionalized GO-based powders leads to a significant improvement in the mortar’s adhesion to the brick substrate (up to 80%) compared to the reference sample, especially in the case of the hydraulic lime mortar incorporating the mixture of GO-Ag and GO-Fly ash, which also showed good resistance to chemical attacks. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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17 pages, 3194 KiB  

Open AccessArticle

Manufacture and Characterization of Polypropylene (PP) and High-Density Polyethylene (HDPE) Blocks for Potential Use as Masonry Component in Civil Construction

by Taiza Ferreira, Gleisson Amaral Mendes, Andrielli Morais de Oliveira and Carmen Gilda Barroso Tavares Dias

Polymers 2022, 14(12), 2463; https://doi.org/10.3390/polym14122463 - 17 Jun 2022

Cited by 7 | Viewed by 3858

Abstract

The lack of suitable destinations for plastics materials can be a global environmental problem. The alternative use of materials for sustainable construction encourages the standardization of waste and promotes effective social, environmental and economic gains at the local level and ensures savings and [...] Read more.

The lack of suitable destinations for plastics materials can be a global environmental problem. The alternative use of materials for sustainable construction encourages the standardization of waste and promotes effective social, environmental and economic gains at the local level and ensures savings and income for communities. The aim of this paper is the development, manufacture, and characterization of PP and HDPE recycled polyolefin blocks as masonry components in civil construction. These blocks were manufactured by the rotational molding process. Besides this, the mechanical, physical, impact and flammability properties of the blocks were studied. In conclusion, HDPE showed better behavior than PP in tests realized. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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24 pages, 9660 KiB  

Open AccessArticle

The Effects of Graphene Oxide-Silica Nano-Hybrid Materials on the Rheological Properties, Mechanical Properties, and Microstructure of Cement-Based Materials

by Zizhi Long, Youzhi Chen, Weisong Yin, Xiuqi Wu and Yun Wang

Materials 2022, 15(12), 4207; https://doi.org/10.3390/ma15124207 - 14 Jun 2022

Cited by 6 | Viewed by 1896

Abstract

Despite their excellent performance, two-dimension nanomaterials have certain limitations in improving the performance of cement-based materials due to their poor dispersity in the alkaline environment. This paper has synthesized a new two-dimension stacked GO-SiO₂ (GOS) hybrid through the sol-gel method. Nano-SiO₂ [...] Read more.

Despite their excellent performance, two-dimension nanomaterials have certain limitations in improving the performance of cement-based materials due to their poor dispersity in the alkaline environment. This paper has synthesized a new two-dimension stacked GO-SiO₂ (GOS) hybrid through the sol-gel method. Nano-SiO₂ is coated on the surface of GO with wrinkling characteristics, and the atomic ratio of C, O, and Si in GOS is 1:1.69:0.57. The paper discusses the impacts on the spreading, Marsh cone flow time, rheological properties, mechanical properties, and microstructure of cement-based materials for the GOS at different mixing quantities. Furthermore, with the same mixing quantity of 0.01%, the influences on the dispersity, flow properties, rheological parameters, and mechanical properties of GOS and graphene oxide (GO) are compared. Lastly, fuzzy matrix analysis has been adopted to analyze the comprehensive performance of cement-based materials containing GOS. The research results indicate that, compared with the reference sample, the spreading for the GOS cement mortar with 0.01% mixing quantity was reduced by 4.76%, the yield shear stress increased by 37.43%, and the equivalent plastic viscosity was elevated by 2.62%. In terms of the 28 d cement pastes, the compressive and flexural strength were boosted by 27.17% and 42.86%, respectively. According to the optical observation, GOS shows better dispersion stability in the saturated calcium hydroxide solution and simulated pore solution than GO. Compared with the cement-based materials with the same mixing quantity (0.01%), GOS has higher spreading, lower shear yield stress, and higher compressive and flexural strength than GO. Finally, according to the results of fuzzy matrix analysis, when the concentration of GOS is 0.01%, it presents a more excellent comprehensive performance with the highest score. Among the performance indicators, the most significant improvement was in the flexural properties of cement-based materials, which increased from 8.6 MPa to 12.3 MPa on the 28 d. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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22 pages, 9631 KiB  

Open AccessArticle

Simple Compressive Strength Results of Sodium-Hydroxide- and Sodium-Silicate-Activated Copper Flotation Tailing Geopolymers

by Hengels Castillo, Thomas Droguett, Mario Vesely, Pamela Garrido and Sergio Palma

Appl. Sci. 2022, 12(12), 5876; https://doi.org/10.3390/app12125876 - 9 Jun 2022

Cited by 4 | Viewed by 1896

Abstract

Geopolymers are created by mixing a source of aluminosilicates, which can be natural or by-products of other industries, with an alkaline solution, which dissolves the aluminates and silicates present in this source, where after a polymerization process, an N-A-S-H gel is formed, which [...] Read more.

Geopolymers are created by mixing a source of aluminosilicates, which can be natural or by-products of other industries, with an alkaline solution, which dissolves the aluminates and silicates present in this source, where after a polymerization process, an N-A-S-H gel is formed, which is responsible for providing the properties that characterize geopolymers. Among the variety of existing geopolymers, those based on by-products from other industries stand out since they were demonstrated to be a less-polluting alternative for concrete production than ordinary Portland cement (OPC). Due to the above, it is essential to study copper flotation tailings as raw material to generate geopolymers. The excessive amounts of existing tailing deposits also produce different risks for the nearby communities. Therefore, using this industrial waste as a construction material would provide several environmental and economic benefits. This article reports on the experimental work carried out in the laboratory of the Sustainable Mining Research Center CIMS of the Engineering Consulting Company JRI, where the effect of the alkaline activator type on the compressive strength of geopolymers based on copper flotation tailings was analyzed. For this purpose, two geopolymeric mixtures were made with different kinds of alkaline activators; one activated using 100% NaOH and the other activated with 100% sodium silicate (SS). From the results, it was found that the geopolymers activated with 100% SS obtained the highest compressive strength, reaching 36.46 MPa with 7 days of curing at 90 °C, followed by the geopolymers activated with 100% NaOH, where a compressive strength of 22.98 MPa was obtained under the same curing conditions. On the other hand, it was found that both geopolymers created were not leachable according to the TCLP test performed, and thus, these geopolymers were classified as non-toxic materials. In addition, it was found that both geopolymers presented a high infiltration value, making them practically impermeable. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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11 pages, 1447 KiB  

Open AccessArticle

The Effect of Pore Structure on Impact Behavior of Concrete Hollow Brick, Autoclaved Aerated Concrete and Foamed Concrete

by Jian Liu, Yuzhe Ren, Rui Chen, Yuedong Wu and Weidong Lei

Materials 2022, 15(12), 4075; https://doi.org/10.3390/ma15124075 - 8 Jun 2022

Cited by 6 | Viewed by 1816

Abstract

Porous concrete is an energy absorption material, which has been widely used in civil engineering, traffic engineering and disaster reduction engineering. However, the effect of pore structure on the impact behavior of the porous concrete is lacked. In this study, a series of [...] Read more.

Porous concrete is an energy absorption material, which has been widely used in civil engineering, traffic engineering and disaster reduction engineering. However, the effect of pore structure on the impact behavior of the porous concrete is lacked. In this study, a series of drop-weight impact tests were carried out on three typical types of porous concrete, i.e., concrete hollow brick (CHB), autoclaved aerated concrete (AAC) and foamed concrete (FC), to investigate the effect of pore structures on their impact behavior. For comparison, static load tests were also conducted as references. According to the damage to the samples, the developments of impact force, strain, contact stress–strain relationship and absorbed energy during drop-weight during the impact test were measured and analyzed. The results show that the ratio between the peak impact stress and compressive strength of CHB was 0.44, while that of AAC and FC increased to about 0.6, indicating that the small and uniform pore structure in AAC and FC had a higher resistance against impact load than the hollow cavity of CHB. In addition, the elastic recovery strain in AAC increased by about 0.2% and its strain at peak contact stress increased by about 160% for a comparison of CHB, implying that a small open pore structure could enhance ductility. Besides, the peak contact stress of FC was close to that of AAC during impact loading, while the strain at peak contact stress of FC increased by about 36% compared with AAC, revealing that the closed-pore structure could further enhance the deformation potential. Correspondingly, the energy absorption rates of CHB, AAC and FC were 85.9 kJ/s, 54.4 kJ/s and 49.7 kJ/s, respectively, where AAC decreased by about 58% compared with CHB, and FC decreased by about 10% compared with AAC. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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14 pages, 3525 KiB  

Open AccessArticle

Retardation Effects of Filter Mud in Molasses on Composite Silicate Cement

by Xun He, Hui Jiang, Xin Wan, Kequan Chen and Pingkai Ouyang

Materials 2022, 15(11), 3989; https://doi.org/10.3390/ma15113989 - 3 Jun 2022

Cited by 1 | Viewed by 1527

Abstract

The filter mud in molasses has a significant inhibitory effect on biological activity and cannot be utilised by organisms; therefore, before molasses are biotransformed, the filter mud will be separated and directly discarded in the environment. In this study, the filter mud was [...] Read more.

The filter mud in molasses has a significant inhibitory effect on biological activity and cannot be utilised by organisms; therefore, before molasses are biotransformed, the filter mud will be separated and directly discarded in the environment. In this study, the filter mud was used as the retarder of cement concrete OPC 42.5 for the first time. It was found that when 0.2–0.8% filter mud was added to fresh cement concrete OPC PC 42.5, the hardening time of cement slurry was significantly prolonged due to the synergistic retarding effect of sugar, colloid and total cellulose in the filter mud. In addition, the compressive strength of cement concrete mixed with the filter mud in the early stage (<10 days), middle stage (10–100 days) and later stage (180 days) was significantly higher than that of cement concrete and cement concrete mixed with commercial asphalt lignosulfonate. These results showed that the filter mud in molasses could realise harmless and resource utilisation, which could promote the comprehensive utilisation of molasses. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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19 pages, 4997 KiB  

Open AccessArticle

Behaviour of Hybrid Fibre-Reinforced Ternary Blend Geopolymer Concrete Beam-Column Joints under Reverse Cyclic Loading

by Veerappan Sathish Kumar, Namasivayam Ganesan, Pookattu Vattarambath Indira, Gunasekaran Murali and Nikolai Ivanovich Vatin

Polymers 2022, 14(11), 2239; https://doi.org/10.3390/polym14112239 - 31 May 2022

Cited by 9 | Viewed by 2024

Abstract

Beam–column joints are extremely vulnerable to lateral and vertical loads in reinforced concrete (RC) structures. This insufficiency in joint performance can lead to the failure of the whole structure in the event of unforeseen seismic and wind loads. This experimental work was conducted [...] Read more.

Beam–column joints are extremely vulnerable to lateral and vertical loads in reinforced concrete (RC) structures. This insufficiency in joint performance can lead to the failure of the whole structure in the event of unforeseen seismic and wind loads. This experimental work was conducted to study the behaviour of ternary blend geopolymer concrete (TGPC) beam-column joints with the addition of hybrid fibres, viz., steel and polypropylene fibres, under reverse cyclic loads. Nine RC beam-column joints were prepared and tested under reverse cyclic loading to recreate the conditions during an earthquake. M55 grade TGPC was designed and used in this present study. The primary parameters studied in this experimental investigation were the volume fractions of steel fibres (0.5% and 1.0%) and polypropylene fibres, viz., 0.1 to 0.25%, with an increment of 0.05%. In this study, the properties of hybrid fibre-reinforced ternary blend geopolymer concrete (HTGPC) beam-column joints, such as their ductility, energy absorption capacity, initial crack load and peak load carrying capacity, were investigated. The test results imply that the hybridisation of fibres effectively enhances the joint performance of TGPC. Also, an effort was made to compare the shear strength of HTGPC beam-column connections with existing equations from the literature. As the available models did not match the actual test results, a method was performed to obtain the shear strength of HTGPC beam-column connections. The developed equation was found to compare convincingly with the experimental test results. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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19 pages, 4966 KiB  

Open AccessArticle

A New Creep–Fatigue Interaction Model for Predicting Deformation of Coarse-Grained Soil

by Jie Zhang, Qiuhua Rao and Wei Yi

Materials 2022, 15(11), 3904; https://doi.org/10.3390/ma15113904 - 30 May 2022

Cited by 1 | Viewed by 1575

Abstract

Studying the creep–fatigue interaction of the coarse-grained soil (CGS) is very important for safety assessment and disaster prevention in subgrade engineering. Current research work is mainly focused on single creep or fatigue deformation. In this paper, a new creep–fatigue interaction model is established [...] Read more.

Studying the creep–fatigue interaction of the coarse-grained soil (CGS) is very important for safety assessment and disaster prevention in subgrade engineering. Current research work is mainly focused on single creep or fatigue deformation. In this paper, a new creep–fatigue interaction model is established to predict the creep–fatigue interaction deformation of different gradation CGS based on the rheological mechanics and the interactive relationship between creep and fatigue complex compliance method. Triaxial creep–fatigue interaction tests of different gradations CGS under different average stresses and frequencies were conducted to verify the new creep–fatigue interaction model. Research results show that for the creep–fatigue and fatigue–creep interaction, the fatigue deformation is always larger than the creep deformation under the same stress level. For the creep–fatigue multi-interaction, the second creep and fatigue deformation are always smaller than the first creep and fatigue deformation. The results of the triaxial creep–fatigue interaction tests verify the validity of this new model. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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Supplementary material:
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11 pages, 884 KiB  

Open AccessArticle

Ecotoxicity and Biodegradation of Sustainable Environment-Friendly Bone-Glue-Based Adhesive Suitable for Insulation Materials

by Klára Kobetičová, Martin Böhm, Miloš Jerman, Jaroslav Dušek and Robert Černý

Polymers 2022, 14(11), 2209; https://doi.org/10.3390/polym14112209 - 29 May 2022

Cited by 5 | Viewed by 2481

Abstract

Bone glue with sodium lignosulfonate is a protein-based adhesive. Their combination leads to strong binding necessary for the achievement of adhesive properties. However, biodegradation and ecotoxicity of materials composed of bone glue and sodium lignosulfonate has never been studied before. In this paper, [...] Read more.

Bone glue with sodium lignosulfonate is a protein-based adhesive. Their combination leads to strong binding necessary for the achievement of adhesive properties. However, biodegradation and ecotoxicity of materials composed of bone glue and sodium lignosulfonate has never been studied before. In this paper, the biodegradation potential of the mixture of bone glue, lignosulfonate and rape straw modified by water or NaOH on an agar test with aerial molds and in acute aquatic tests with mustard, yeasts, algae and crustaceans was analyzed. Epoxy resin as an ecologically unfriendly binder was used as a negative control and pure rape straw as a background. The results indicated that all samples were covered by molds, but the samples containing straw treated by NaOH showed lower biodegradability. The ecotoxicological effects varied among the applied model organisms. Artemia salina was not able to survive and S. alba could not prolong roots in the eluates of all samples (100% inhibition). Freshwater algae (D. subspicatus) were not significantly affected by the samples (max. 12% inhibition, max. 16% stimulation). The biomass of yeasts (S. cerevisae) was strongly stimulated in the presence of eluates in a comparison to control (max. 38% stimulation). Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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17 pages, 5316 KiB  

Open AccessArticle

Application of Iron Tailings-Based Composite Supplementary Cementitious Materials (SCMs) in Green Concrete

by Yannian Zhang, Daokui Yang, Xiaowei Gu, Hao Chen and Zhijun Li

Materials 2022, 15(11), 3866; https://doi.org/10.3390/ma15113866 - 28 May 2022

Cited by 7 | Viewed by 1923

Abstract

How to treat the iron tailings of mining solid waste with high value is an urgent problem on a global scale. In recent years, the application of iron tailings in the building materials industry has attracted the attention of many scholars. The conversion [...] Read more.

How to treat the iron tailings of mining solid waste with high value is an urgent problem on a global scale. In recent years, the application of iron tailings in the building materials industry has attracted the attention of many scholars. The conversion of iron tailings into green building materials helps achieve carbon neutrality and high-value utilization of solid waste, and promotes sustainable development. Although iron tailings have been extensively studied as supplementary cementitious materials, the performance of concrete is not ideal due to its low activity. In this study, the hybrid supplementary cementitious materials system was prepared by iron tailings, phosphorus slag, and steel slag, and the effects of supplementary cementitious materials type, iron tailings content, iron tailings grinding time, and supplementary cementitious materials content on concrete performance were studied. The compressive properties, iron tailings properties, pore structure, interfacial transition zone, and element distribution of hydration products of concrete were tested by compressive strength tests, X-ray Diffractometer (XRD), X-ray Photoelectron Spectroscopy (XPS), Mercury Intrusion Porosimetry (MIP), Backscattering Electron Tests (BSE), and Energy Dispersive Spectrometer (EDS). The results show that further grinding improves the iron tailings activity. There is a synergistic mechanism between steel slag and phosphorus slag in the composite supplementary cementitious materials, which overcomes the low activity defect of iron tailings and produces concrete with a compressive strength exceeding 40 MPa. The composite supplementary cementitious materials can optimize the interfacial transition zone of the concrete interface and reduce the calcium–silicon ratio of the hydration products. However, it will deteriorate the pore structure of the concrete matrix, cause part of the concrete matrix to be damaged and lead to a loss of compressive strength, and the loss is acceptable. This work broadens the methods of comprehensive utilization of iron tailings and also provides a reference for a more detailed understanding of the properties of iron tailings-based concrete. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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24 pages, 32783 KiB  

Open AccessArticle

Effect of Wood Properties and Building Construction on Thermal Performance of Radiant Floor Heating Worldwide

by Enrique Ángel Rodríguez Jara, Álvaro Ruiz-Pardo, Marta Conde García and José Antonio Tenorio Ríos

Appl. Sci. 2022, 12(11), 5427; https://doi.org/10.3390/app12115427 - 27 May 2022

Cited by 4 | Viewed by 2578

Abstract

Due to its relatively lower thermal conductivity, the suitability of wood is called into question when selecting the flooring material best suited to radiant heating systems. The European standard EN 1264 considers floorings with a thermal resistance over 0.15 m² K/W to [...] Read more.

Due to its relatively lower thermal conductivity, the suitability of wood is called into question when selecting the flooring material best suited to radiant heating systems. The European standard EN 1264 considers floorings with a thermal resistance over 0.15 m² K/W to be out of scope. This belief was partially disproved in a previous article that studied wooden floors for Madrid’s climate. However, the effect of climate still needs to be addressed. The present study extends the previous research to worldwide climates and aimed to answer the following questions: (1) Do the lowest thermal conductivity woods present good thermal performance when used in radiant floors? (2) Should the flooring have a maximum thermal resistance value? (3) Is the standard thermal resistance limit of 0.15 m² K/W objectively justified? And (4) Do the answers of the preceding questions depend on the climate and the construction characteristics? To answer these questions, 28 cities were selected according to the Köppen–Geiger climate classification. In each city, 216 different dwellings were simulated with 60 wood floorings and one of low thermal resistance as a reference, comprising a total of 368,928 cases. Thermal performance was evaluated in terms of three parameters: energy demand, thermal comfort, and start-up lag time. Consequently, the answers to the previous questions were: (1) The lowest thermal conductivity woods can be used efficiently worldwide in radiant floor heating systems with start-up lag times close to that of the reference flooring; (2) There is no limit value for thermal resistance for floorings that can be applied to all dwellings and climates; (3) No objective justification was found for establishing a thermal resistance limit for flooring of 0.15 m² K/W; and (4) Climate and construction characteristics can play an important role in the correct selection of flooring properties, especially in severe winters and dwellings with the greatest outdoor-exposed envelope and the worst insulation. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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12 pages, 2330 KiB  

Open AccessArticle

Study on Properties and Optimization of Ternary Auxiliary Cementing Materials for IOTs

by Yannian Zhang, Xiangkun Zhang, Xiaowei Gu, Ting Wang and Bonan Liu

Materials 2022, 15(11), 3851; https://doi.org/10.3390/ma15113851 - 27 May 2022

Cited by 2 | Viewed by 1359

Abstract

In order to control energy consumption and reduce pollution, the use of supplementary cementitious materials (SCMs) instead of cement to produce green cementitious materials can save energy, reduce emissions and achieve sustainable development. This study demonstrates the possibility of developing SCMs with iron [...] Read more.

In order to control energy consumption and reduce pollution, the use of supplementary cementitious materials (SCMs) instead of cement to produce green cementitious materials can save energy, reduce emissions and achieve sustainable development. This study demonstrates the possibility of developing SCMs with iron tailings (IOTs), fly ash (FA) and ceramic powder (CP) ternary system, as well as the optimization and improvement scheme of gelation activation. The effects of activator dosage, mix ratio and substitution rate on mechanical properties of ternary SCMs system were investigated. The formation and evolution of hydration products were analyzed by differential thermogravimetric analysis (DTA) and scanning electron microscopy (SEM). The results of the study show that there is synergy in the system. The results show that there is synergy in the system and the hydration reaction is sufficient. At the substitution rate of 30%, the doping ratio of IOTs, CP and FA is 1:2:2 and the Ca(OH)₂ is 0.6%, the strength reaches 39.9 MPa and the activity index is 91.5%, which can provide a basis for the application and more in-depth study of IOTs multi SCMs. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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15 pages, 3554 KiB  

Open AccessArticle

Macroencapsulation of Paraffin in a Polymer–Gypsum Composite Using Granulation Technique

by Krzysztof Powała, Andrzej Obraniak, Dariusz Heim and Andrzej Mrowiec

Materials 2022, 15(11), 3783; https://doi.org/10.3390/ma15113783 - 25 May 2022

Cited by 3 | Viewed by 1548

Abstract

This article shows research confirming the thesis on the use of a new material in the form of gypsum, paraffin, and polymer. The article presents an innovative method of preparing plaster with PCM and polymer. Using a special wheel, it was possible to [...] Read more.

This article shows research confirming the thesis on the use of a new material in the form of gypsum, paraffin, and polymer. The article presents an innovative method of preparing plaster with PCM and polymer. Using a special wheel, it was possible to produce a granulate consisting of a mixture of gypsum and paraffin and then spray it with various preparations in order to select the best substance for encapsulation. The article covers strength tests of the obtained granulate depending on the encapsulated material, as well as screening and separation tests depending on the diameter of the granulate. Then, samples consisting of each type of granulate were prepared and poured with gypsum. Studies of the heat conductivity coefficient, the volumetric heat capacity, and thermal diffusivity were carried out. After obtaining the test results, the development of temperature changes was examined for two gypsum boards, one made of raw gypsum and one containing granules, which achieved the best results. The test was carried out using special lamps that were supposed to emit a total of 1000 W of power. The temperature in front of and behind the plates was examined and appropriate conclusions were drawn. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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16 pages, 4069 KiB  

Open AccessArticle

Effect of Processed Oil on Asphalt Binder Properties

by Navid Hemmati, Jihyeon Yun, Hyunhwan Kim, Moon-Sup Lee and Soon-Jae Lee

Materials 2022, 15(11), 3739; https://doi.org/10.3390/ma15113739 - 24 May 2022

Cited by 3 | Viewed by 1470

Abstract

This study investigates the effectiveness of processed oil in the modification of PG 64-22 and PG 76-22 by assessing their physical and rheological properties, and multiple comparison was conducted between the two binders. The base binders PG 64-22 and PG 76-22 were blended [...] Read more.

This study investigates the effectiveness of processed oil in the modification of PG 64-22 and PG 76-22 by assessing their physical and rheological properties, and multiple comparison was conducted between the two binders. The base binders PG 64-22 and PG 76-22 were blended with processed oil at four different percentages of contents (3%, 6%, 9% and 12% by the weight of the binder) and compared with the control binder in each test. The base and modified binders were artificially short-term and long-term aged using a rolling thin film oven (RTFO) and pressure aging vessel (PAV) procedures. Superpave binder tests were performed on the modified binders by applying a rotational viscometer (RV), dynamic shear rheometer (DSR), and bending beam rheometer (BBR). The comparisons and results presented in this study indicate that (1) the processed oil has a significant effect on the binders’ viscosity, which changes with respect to the increment of processed oil content. The viscosity of both modified binders decreased with the addition of 3, 6, 9 and 12% processed oil; (2) the performed DSR test showed that the addition of processed oil had a negative effect on the rutting resistance for both binders, since in PG 64-22, G*/Sin δ values decreased by 55, 65, 75 and 83% with the addition of 3, 6, 9 and 12% processed oil, respectively, while a decrement of G*/Sin δ of 24, 45, 58 and 65% with the addition of 3, 6, 9 and 12% processed oil was observed in PG 76-22; meanwhile, the fatigue cracking performance was improved and was found to be effective, while G* Sin δ in PG76-22 decreased by 9, 30, 36, and 52% and in PG 64-22 by 27, 44, 53, and 67% with the addition of 3, 6, 9 and 12% processed oil; (3) the results from the BBR test indicate significant improvement in the thermal cracking properties of the binders. The addition of 3, 6, 9 and 12% processed oil resulted in a decrease in the stiffness of both the PG 64-22 and PG 76-22 binders, with a positive effect consequently being observed on the m-values of the binders. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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9 pages, 5086 KiB  

Open AccessArticle

Strength and Microstructure of Geopolymer Based on Fly Ash and Metakaolin

by Salim Barbhuiya and Edmund Pang

Materials 2022, 15(10), 3732; https://doi.org/10.3390/ma15103732 - 23 May 2022

Cited by 13 | Viewed by 2341

Abstract

The production of Portland cement is widely regarded as a major source of greenhouse gas emissions. This contributes to 6–7% of total CO₂ emissions, according to the International Energy Agency. As a result, several efforts have been made in recent decades to [...] Read more.

The production of Portland cement is widely regarded as a major source of greenhouse gas emissions. This contributes to 6–7% of total CO₂ emissions, according to the International Energy Agency. As a result, several efforts have been made in recent decades to limit or eliminate the usage of Portland cement in concrete. Geopolymer has garnered a lot of attention among the numerous alternatives due to its early compressive strength, low permeability, high chemical resistance, and great fire-resistant behaviour. This study looks at the strength and microstructure of geopolymer based on fly ash and a combination of metakaolin and fly ash. Compressive strengths were measured at 7, 14, and 28 days, and microstructure was examined using SEM and XRD. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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Supplementary material:
Supplementary File 1 (ZIP, 263 KiB)

18 pages, 8107 KiB  

Open AccessArticle

Size Effect of Hydrated Lime on the Mechanical Performance of Asphalt Concrete

by Amjad Albayati, Yu Wang and Jonathan Haynes

Materials 2022, 15(10), 3715; https://doi.org/10.3390/ma15103715 - 22 May 2022

Cited by 12 | Viewed by 2243

Abstract

Despite widespread agreement on the beneficial nature of hydrated lime (HL) addition to asphalt concrete mixes, understanding of the effect of HL particle size is still limited. Previous investigations have focused mainly on two different size comparisons, and so certain guidance for a [...] Read more.

Despite widespread agreement on the beneficial nature of hydrated lime (HL) addition to asphalt concrete mixes, understanding of the effect of HL particle size is still limited. Previous investigations have focused mainly on two different size comparisons, and so certain guidance for a practical application cannot yet be produced. This study investigates three distinct sizes of HL, in the range of regular, nano, and sub-nano scales, for their effects on the properties of modified asphalt concretes. Five different percentages of HL as a partial replacement of ordinary limestone filler in asphalt concrete mixes were studied for wearing course application purposes. Experimental tests were conducted to evaluate the mechanical properties, including resistance to plastic flow, volumetric properties, moisture susceptibility, resilient modulus, and permanent deformation. The results revealed that a positive correlation exists between the mechanical properties and the fineness of HL particle sizes. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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20 pages, 4569 KiB  

Open AccessArticle

Assembly Solution for Modular Buildings: Development of an Automated Connecting Device for Light-Framed Structures

by Laurence Picard, Pierre Blanchet and André Bégin-Drolet

Buildings 2022, 12(5), 672; https://doi.org/10.3390/buildings12050672 - 18 May 2022

Cited by 9 | Viewed by 3936

Abstract

The prefabricated construction industry, also known as off-site construction, has been operating in North America for several years now and differs from traditional construction in its much shorter project timelines, lower costs, and increased build quality. However, the lack of a suitable and [...] Read more.

The prefabricated construction industry, also known as off-site construction, has been operating in North America for several years now and differs from traditional construction in its much shorter project timelines, lower costs, and increased build quality. However, the lack of a suitable and efficient assembly solution has been identified by many as a barrier to the use of off-site construction for larger buildings. To maximise the benefits of off-site manufacturing for multistorey buildings, an automated connection solution is presented in this paper. A new plug-in self-locking device was developed according to the following product design phases: on-site observations, definition of the problem and product specifications, solution generation, prototyping, fabrication, and testing. The plug-in self-locking device allows the assembly process to be accelerated by eliminating the fastening steps and a higher completion of modules off-site to be achieved. The design bears the compressive, tensile, and shear loads and contributes to the load path of the building. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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Supplementary material:
Supplementary File 1 (ZIP, 1228 KiB)

18 pages, 10424 KiB  

Open AccessArticle

Portland and Belite Cement Hydration Acceleration by C-S-H Seeds with Variable w/c Ratios

by Alejandro Morales-Cantero, Ana Cuesta, Angeles G. De la Torre, Oliver Mazanec, Pere Borralleras, Kai S. Weldert, Daniela Gastaldi, Fulvio Canonico and Miguel A. G. Aranda

Materials 2022, 15(10), 3553; https://doi.org/10.3390/ma15103553 - 16 May 2022

Cited by 12 | Viewed by 2249

Abstract

The acceleration of very early age cement hydration by C-S-H seeding is getting attention from scholars and field applications because the enhanced early age features do not compromise later age performances. This acceleration could be beneficial for several low-CO₂ cements as a [...] Read more.

The acceleration of very early age cement hydration by C-S-H seeding is getting attention from scholars and field applications because the enhanced early age features do not compromise later age performances. This acceleration could be beneficial for several low-CO₂ cements as a general drawback is usually the low very early age mechanical strengths. However, the mechanistic understanding of this acceleration in commercial cements is not complete. Reported here is a contribution to this understanding from the study of the effects of C-S-H gel seeding in one Portland cement and two belite cements at two widely studied water–cement ratios, 0.50 and 0.40. Two commercially available C-S-H nano-seed-based admixtures, i.e., Master X-Seed 130 and Master X-Seed STE-53, were investigated. A multi-technique approach was adopted by employing calorimetry, thermal analysis, powder diffraction (data analysed by the Rietveld method), mercury intrusion porosimetry, and mechanical strength determination. For instance, the compressive strength at 1 day for the PC (w/c = 0.50) sample increased from 15 MPa for the unseeded mortar to 24 and 22 MPs for the mortars seeded with the XS130 and STE53, respectively. The evolution of the amorphous contents was determined by adding an internal standard before recording the powder patterns. In summary, alite and belite phase hydrations, from the crystalline phase content evolutions, are not significantly accelerated by C-S-H seedings at the studied ages of 1 and 28 d for these cements. Conversely, the hydration rates of tetracalcium alumino-ferrate and tricalcium aluminate were significantly enhanced. It is noted that the degrees of reaction of C₄AF for the PC paste (w/c = 0.40) were 10, 30, and 40% at 1, 7, and 28 days. After C-S-H seeding, the values increased to 20, 45, and 60%, respectively. This resulted in larger ettringite contents at very early ages but not at 28 days. At 28 days of hydration, larger amounts of carbonate-containing AFm-type phases were determined. Finally, and importantly, the admixtures yielded larger amounts of amorphous components in the pastes at later hydration ages. This is justified, in part, by the higher content of amorphous iron siliceous hydrogarnet from the enhanced C₄AF reactivity. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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18 pages, 4346 KiB  

Open AccessArticle

A Resistivity Plate Loading Device for Assessing the Factors Affecting the Stiffness of a Cement-Stabilized Subgrade

by Huaiping Feng, Ackah Frank Siaw and Hailiang Wang

Materials 2022, 15(10), 3453; https://doi.org/10.3390/ma15103453 - 11 May 2022

Cited by 2 | Viewed by 1819

Abstract

The extent of mixing in the stabilization process and the control of the cement content (C) and water content (w) in the mixture are key to the outcome of the engineering performance of a cement-stabilized subgrade. Intelligent Compaction (IC) [...] Read more.

The extent of mixing in the stabilization process and the control of the cement content (C) and water content (w) in the mixture are key to the outcome of the engineering performance of a cement-stabilized subgrade. Intelligent Compaction (IC) quality control has improved quality control and management practices during construction. Intelligent Compaction Measurement Values (ICMVs) selected to evaluate the stiffness properties of cement-stabilized soils do not directly relate to the stiffness properties of the cement-stabilized subgrade and do not consider w and C. Additional tests need to be conducted for calibration of ICMVs. In this study, our solution is the development of a resistivity plate loading test. The resistivity plate loading test features the flexibility in determining the soil stiffness, w, C, and other important factors, such as the time of test effect (hydration) (T) and dry density (ρ_d). To verify the accuracy of the testing method, laboratory experimental studies were conducted on cemented soils considering ρ_d, w, C, and T at different factor levels. Multiple response studies based on grey rational analysis (GRA) were conducted. Analysis of the input factors was performed, and their effects on the measured responses were quantified. According to the study, the ρ measured by the device was a powerful indicator of stiffness, ρ_d, w, C, and T, which showed that the device can be useful equipment for quality control and an advancement in the in situ testing technologies and test equipment. A statistical regression model based on the linear and linear plus interaction terms among the factors is proposed to predict the average responses. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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20 pages, 11122 KiB  

Open AccessArticle

Mechanical Performance of RPC and Steel–RPC Composite Structure with Different Fiber Parameters: Experimental and Theoretical Research

by Jun Luo, Ziran Quan, Xudong Shao, Fangyuan Li and Shangwen He

Polymers 2022, 14(10), 1933; https://doi.org/10.3390/polym14101933 - 10 May 2022

Cited by 2 | Viewed by 1474

Abstract

This paper aims to explore the material properties of RPC and transverse-bending performance, as well as the crack-width-calculation theory of a densely reinforced steel–RPC composite structure with different fiber parameters. Two fiber types (straight fiber, hybrid fiber) and four fiber volume contents (2%, [...] Read more.

This paper aims to explore the material properties of RPC and transverse-bending performance, as well as the crack-width-calculation theory of a densely reinforced steel–RPC composite structure with different fiber parameters. Two fiber types (straight fiber, hybrid fiber) and four fiber volume contents (2%, 2.5%, 3%, 3.5%) were selected to explore the mechanical properties of RPC materials, and the influences of fiber parameters on compressive strength, modulus of elasticity, flexural strength and axial tensile property were investigated. Eight steel–RPC composite plates with different design parameters (fiber type and reinforcement ratio) were conducted to study the transverse-bending performance of steel–RPC composite deck structures. The results show that the addition of 3.5% hybrid fibers to the RPC matrix leads to the optimum axial tensile and flexural properties. Furthermore, the failure mode, load–displacement curve, crack occurrence and propagation characteristics of the composite structure are analyzed in detail. Based on the experimental results, the calculation methods of reinforcement stress and crack width of densely reinforced steel–RPC composite structure are proposed. The calculated results of reinforcement stress and maximum crack width are in good agreement with the actual measured values, which can provide a reference for engineering design. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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15 pages, 2288 KiB  

Open AccessReview

Precipitation Polymerization: A Powerful Tool for Preparation of Uniform Polymer Particles

by Randi Zhang, Rong Gao, Qingqiang Gou, Jingjing Lai and Xinyang Li

Polymers 2022, 14(9), 1851; https://doi.org/10.3390/polym14091851 - 30 Apr 2022

Cited by 24 | Viewed by 7163

Abstract

Precipitation polymerization (PP) is a powerful tool to prepare various types of uniform polymer particles owing to its outstanding advantages of easy operation and the absence of any surfactant. Several PP approaches have been developed up to now, including traditional thermo-induced precipitation polymerization [...] Read more.

Precipitation polymerization (PP) is a powerful tool to prepare various types of uniform polymer particles owing to its outstanding advantages of easy operation and the absence of any surfactant. Several PP approaches have been developed up to now, including traditional thermo-induced precipitation polymerization (TRPP), distillation precipitation polymerization (DPP), reflux precipitation polymerization (RPP), photoinduced precipitation polymerization (PPP), solvothermal precipitation polymerization (SPP), controlled/‘‘living’’ radical precipitation polymerization (CRPP) and self-stabilized precipitation polymerization (2SPP). In this review, a general introduction to the categories, mechanisms, and applications of precipitation polymerization and the recent developments are presented, proving that PP has great potential to become one of the most attractive polymerization techniques in materials science and bio-medical areas. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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18 pages, 8740 KiB  

Open AccessArticle

Method for Manufacturing Corn Straw Cement-Based Composite and Its Physical Properties

by Boyu Niu and Byeong Hwa Kim

Materials 2022, 15(9), 3199; https://doi.org/10.3390/ma15093199 - 28 Apr 2022

Cited by 9 | Viewed by 2137

Abstract

This paper introduces an innovative method for making cement-based composites from corn straw plants, and investigates the strength, thermal conductivity, and hydration characteristics of the composites. Corn straw is a natural, renewable, and breathable thermal insulation composite that contains cellular sealed pores. Corn [...] Read more.

This paper introduces an innovative method for making cement-based composites from corn straw plants, and investigates the strength, thermal conductivity, and hydration characteristics of the composites. Corn straw is a natural, renewable, and breathable thermal insulation composite that contains cellular sealed pores. Corn straw contains a large amount of soluble cellulosic sugar, which hinders the hydration reaction of Portland cement and affects the use of corn straw as a building material. In this study, a 3 wt.% siliceous solution was used for surface treatment of corn straw particles to prevent cellulosic sugar from affecting the hydration performance of Portland cement. The composition of added cement-based composite materials with treated corn straw at the dosage of 11–20 wt.% was investigated. The test results showed that the corn straw cement-based composite (CSCC) had an optimal thermal conductivity of 0.102–0.112 (W/(m·K)) and a minimum compressive strength of above 1 MPa. The hydration performance of four typical CSCCs was examined using XRD, SEM, and EDS. The experimental results of this study may help to increase the comprehensive utilization of corn straw. The manufacturing method of the composite materials is simple, effective, and convenient for popularization and application, and it provides a new important technical measure to solve the problem of high energy consumption in rural houses. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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19 pages, 5807 KiB  

Open AccessArticle

Stress–Strain Model for Lightweight Aggregate Concrete Reinforced with Carbon–Polypropylene Hybrid Fibers

by Xue Yang, Tao Wu and Xi Liu

Polymers 2022, 14(9), 1675; https://doi.org/10.3390/polym14091675 - 20 Apr 2022

Cited by 9 | Viewed by 2270

Abstract

This research aimed to investigate the hybrid effects of carbon and polypropylene fibers on the stress–strain behavior of lightweight aggregate concrete (LWAC). The considered test variables were two fiber volume fractions of 0.2% and 0.4% and two water/binder ratios of 0.27 and 0.30. [...] Read more.

This research aimed to investigate the hybrid effects of carbon and polypropylene fibers on the stress–strain behavior of lightweight aggregate concrete (LWAC). The considered test variables were two fiber volume fractions of 0.2% and 0.4% and two water/binder ratios of 0.27 and 0.30. Eighteen groups of prisms fabricated with fiber-reinforced LWAC were tested under axial compressive load. Experimental studies were carried out to analyze the influence of different fiber combinations on the complete stress–strain behavior. It was found that the carbon–polypropylene hybrid fibers led to toughness enhancement that was numerically more significant than the sum of individual fibers, indicating a positive synergistic effect between them. Finally, a mathematical expression of the stress–strain curve accounting for the fiber combinations was developed. Compared with existing stress–strain models, the proposed model shows better accuracy in predicting the effect of carbon and polypropylene fibers in both single and hybrid forms on the stress–strain curve of LWAC. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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16 pages, 3271 KiB  

Open AccessArticle

Effects of Ultrafine Blast Furnace Slag on the Microstructure and Chloride Transport in Cementitious Systems under Cyclic Drying–Wetting Conditions

by Wei Li, Liming Yi, Wen Jiang, Hua Dong and Yong Zhang

Appl. Sci. 2022, 12(8), 4064; https://doi.org/10.3390/app12084064 - 18 Apr 2022

Cited by 4 | Viewed by 1679

Abstract

This paper presents experimental investigations into the effects of ultrafine blast furnace slag on microstructure improvements against chloride penetration in saturated and unsaturated cementitious systems exposed to cyclic drying–wetting conditions. The hydration kinetics of ultrafine slag powders and pore solution chemistry in slag-blended [...] Read more.

This paper presents experimental investigations into the effects of ultrafine blast furnace slag on microstructure improvements against chloride penetration in saturated and unsaturated cementitious systems exposed to cyclic drying–wetting conditions. The hydration kinetics of ultrafine slag powders and pore solution chemistry in slag-blended cementitious systems at different ages, together with the main hydration products and pore structure characteristics, were determined. The chloride profiles accounting for different slag contents and drying–wetting cycles were measured. The results reveal that the reactivity of ultrafine slag can be well described with Avrami’s equation. The dilution effect of the slag predominated the pore solution chemistry, and the pH value decreased with a higher inclusion of slag. An optimal inclusion of 65% slag by mass of the binder corresponding to the finest pore structure and highest hydrotalcite content was found, which provides a reasonable basis for the slow chloride diffusion and high chloride binding. Under drying–wetting exposure, the specimen with a lower saturation exhibited a higher chloride transport caused by capillary absorption in the skin layer. The chloride transport tended to be diffusion controlled after sufficient drying–wetting cycles. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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22 pages, 4519 KiB  

Open AccessReview

Textile-Reinforced Concrete as a Structural Member: A Review

by Sanjay Gokul Venigalla, Abu Bakar Nabilah, Noor Azline Mohd Nasir, Nor Azizi Safiee and Farah Nora Aznieta Abd Aziz

Buildings 2022, 12(4), 474; https://doi.org/10.3390/buildings12040474 - 12 Apr 2022

Cited by 15 | Viewed by 7424

Abstract

Textile-reinforced concrete (TRC) is a form of reinforced concrete, where conventional reinforcement is replaced with textiles or fibers. The high tenacity of the textile fibers results in flexible and durable concrete structures. The literature has been limited to TRC applications in retrofitting and [...] Read more.

Textile-reinforced concrete (TRC) is a form of reinforced concrete, where conventional reinforcement is replaced with textiles or fibers. The high tenacity of the textile fibers results in flexible and durable concrete structures. The literature has been limited to TRC applications in retrofitting and nonstructural applications. Therefore, this article attempts to detangle the progressive research direction on the usage of TRC as a structural member. For this, (i) a bibliometric study using scientometrics analysis to visualize the keyword network, and (ii) qualitative discussions on identified research areas were performed. The literature was categorized into four main research areas, namely material properties of TRC, composite behavior of TRC, bond-slip relations, and TRC applications as structural elements. In addition, the advantages and disadvantages in the usage of TRC as a structural member are discussed in association with the identified research areas. Furthermore, the article proposes future directions to reinforce the research on the usage of TRC as a structural element. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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16 pages, 5931 KiB  

Open AccessArticle

Hydration and Properties of Cement in the Belite-Ye′elimite-Ternesite System

by Guoling Wang, Xiaofei Huang, Yufeng Wu, Qian Zhang, Suhua Ma and Weifeng Li

Materials 2022, 15(8), 2792; https://doi.org/10.3390/ma15082792 - 11 Apr 2022

Cited by 3 | Viewed by 1871

Abstract

Energy consumption and carbon emissions are lower in the production of belite-ye′elimite-ternesite (C₂S-C₄A₃$-C₅S₂$, BYT) clinker than Portland cement (PC) clinker. BYT cement can combine the early strength of CSA cements and the durability [...] Read more.

Energy consumption and carbon emissions are lower in the production of belite-ye′elimite-ternesite (C₂S-C₄A₃$-C₅S₂$, BYT) clinker than Portland cement (PC) clinker. BYT cement can combine the early strength of CSA cements and the durability of belite cements. X-ray diffraction, mercury intrusion porosimetry, isothermal conduction calorimetry and scanning electron microscope were conducted to investigate the hydration process of BYT cement. The hydration products of BYT cement include mainly ettringite, strätlingite and some amorphous AH₃ (aluminum hydroxide). Ternesite did prove an early reactivity in BYT cement. The reaction of ternesite with AH₃ occurs on the surface of ternesite. Ternesite delays the second heat flow peak of ye′elimite. The strength of BYT cement containing 10% ternesite in the prepared clinker exceeds that of other cement at all ages. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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17 pages, 5195 KiB  

Open AccessArticle

Developing Equations for Free Vibration Parameters of Bistable Composite Plates Using Multi-Objective Genetic Programming

by Saeid Saberi, Alireza Sadat Hosseini, Fatemeh Yazdanifar and Saullo G. P. Castro

Polymers 2022, 14(8), 1559; https://doi.org/10.3390/polym14081559 - 11 Apr 2022

Cited by 4 | Viewed by 2075

Abstract

For the last three decades, bistable composite laminates have gained publicity because of their outstanding features, including having two stable shapes and the ability to change these states. A common challenge regarding the analysis of these structures is the high computational cost of [...] Read more.

For the last three decades, bistable composite laminates have gained publicity because of their outstanding features, including having two stable shapes and the ability to change these states. A common challenge regarding the analysis of these structures is the high computational cost of existing analytical methods to estimate their natural frequencies. In the current paper, a new methodology combining the Finite Element Method (FEM) and Multi-Objective Genetic Programming (MOGP) is proposed for the analysis of bistable composite structures, leading to some analytical relations derived to obtain the modal parameters of the shells. To achieve this aim, the data extracted from FEM, consisting of the ratio of the length to width (a/b) and the thickness (t) of the laminate, is split into Train and Validation, and Test, subsets. The former is used in MOGP, and four formulas are proposed for the prediction of the free vibration parameters of bistable laminates. The formulas are checked against the Test subset, and the statistical indices are calculated. An excellent performance is observed for all GP formulas, which indicates the reliability and accuracy of the predictions of these models. Parametric studies and sensitivity analyses are conducted to interpret the trend of input parameters in the GP models and the level of sensitivity of each natural frequency formula to the input parameters. These explicit mathematical expressions can be extended to the other bistable laminates to obtain their natural frequencies on the basis of their geometrical dimensions. The results are validated against the experimental data and verified against FEM outcomes. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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10 pages, 2396 KiB  

Open AccessArticle

Effects of the Water/Cement Ratio on the Properties of 3-3 Type Cement-Based Piezoelectric Composites

by Jian-hong Wang, Hao-xin Sun, Ying-ge Dong, Zhi Cheng and Wei Liu

Materials 2022, 15(8), 2760; https://doi.org/10.3390/ma15082760 - 8 Apr 2022

Cited by 2 | Viewed by 1518

Abstract

In this work, 3-3 type porous lead zirconate titanate (PZT) ceramics were fabricated by incorporating particle-stabilized foams using the gel-casting method. Then, Portland cement pastes with different water/cement ratios (w/c) were cast into the porous ceramics to produce cement-based piezoelectric (PZT-PC) composites. The [...] Read more.

In this work, 3-3 type porous lead zirconate titanate (PZT) ceramics were fabricated by incorporating particle-stabilized foams using the gel-casting method. Then, Portland cement pastes with different water/cement ratios (w/c) were cast into the porous ceramics to produce cement-based piezoelectric (PZT-PC) composites. The effects of w/c on phase structure, microscopic morphology, and electrical properties were studied. The results showed that the amount of hydrated cement products and the density of the PZT–PC composites increased with the increase of w/c from 0.3 to 0.9 and then decreased till w/c achieved a value of 1.1. Correspondingly, the values of both ε_r and d₃₃ increased with the density of the PZT–PC composites, resulting in less defects and greater poling efficiency. When w/c was maintained at 0.9, the 3-3 type cement-based piezoelectric composites presented the greatest K_t value of 40.14% and the lowest Z value of 6.98 MRayls, becoming suitable for applications in civil engineering for structural health monitoring. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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13 pages, 3622 KiB  

Open AccessArticle

Waste Originating from the Cleaning of Flue Gases from the Combustion of Industrial Wastes as a Lime Partial Replacement in Autoclaved Aerated Concrete

by Agnieszka Różycka and Łukasz Kotwica

Materials 2022, 15(7), 2576; https://doi.org/10.3390/ma15072576 - 31 Mar 2022

Cited by 5 | Viewed by 1864

Abstract

This paper aims to study the suitability of partial replacement of lime by waste originating from the cleaning of flue gases from the combustion of industrial wastes in the production of autoclaved aerated concrete (AAC). The compressive strength, bulk density, pore structure, phase [...] Read more.

This paper aims to study the suitability of partial replacement of lime by waste originating from the cleaning of flue gases from the combustion of industrial wastes in the production of autoclaved aerated concrete (AAC). The compressive strength, bulk density, pore structure, phase composition, and microstructure of hydration products of the AAC were analyzed. According to the results, the addition of the waste can effectively enhance the mechanical properties of AAC due to the differences in morphology of hydration product—1.1 nm tobermorite and related dense microstructure. The pore size distribution was significantly influenced by waste addition, which was one of the main reasons for the increase in thermal conductivity. The XRD and SEM results showed that foreign ions introduced with the wastes affect the synthesis of 1.1 nm tobermorite. Moreover, it was shown that waste containing a high content of CaO can be used as lime replacement, which allows reducing CO₂ emissions during the AAC production process. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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15 pages, 5352 KiB  

Open AccessArticle

Design and Evaluation of a Polymer Support Fluid in a Soil–Rock Mixture

by Chunye Ying, Xinli Hu, Peng Xia and Haiyan Zhang

Polymers 2022, 14(7), 1402; https://doi.org/10.3390/polym14071402 - 30 Mar 2022

Viewed by 3269

Abstract

Soil–rock mixtures are commonly encountered in the construction of bored piles. Conventional bentonite support fluids have disadvantages, such as more significant environmental impacts, more complex mixing, bigger site footprint, weaker foundation performance, and overall low economies. The present study conducted a comprehensive investigation [...] Read more.

Soil–rock mixtures are commonly encountered in the construction of bored piles. Conventional bentonite support fluids have disadvantages, such as more significant environmental impacts, more complex mixing, bigger site footprint, weaker foundation performance, and overall low economies. The present study conducted a comprehensive investigation of partially hydrolyzed polyacrylamide (PHPA) polymer fluids, an alternative to bentonite ones, to drill into a soil-limestone mixture. The fluid flow pattern, aging behavior, and the influence of finer silty clay on polymer fluid were explored. The test results showed that polymer fluids were reasonably well fitted to the power-law model and were a good alternative to the conventional bentonite ones. In terms of their aging behavior, the remaining active viscosity of the polymer was at least 70% after a prolonged aging time of up to 30 days, showing the effective on-site use of polymer fluids. The mixing of silty clay significantly reduced the apparent viscosity of polymer fluids, with 10% silty clay causing a viscosity reduction of 76%, indicating the importance of fluid control in drilling these materials. A polymer formula, water + 0.08%PHPA + 0.1~0.5%Na₂CO₃, was proposed and was verified by drilling into a soil–limestone mixture. The polymer fluids led to small radial displacements around the boreholes with a high drilling quality. This work would be helpful for consultants and contractors designing and constructing bored piles in soil and rock mixtures utilizing polymer fluids. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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21 pages, 8150 KiB  

Open AccessArticle

Sulphate Corrosion Mechanism of Ultra-High-Performance Concrete (UHPC) Prepared with Seawater and Sea Sand

by Xin Sun, Tianyu Li, Fangying Shi, Xiaoyan Liu, Yingxia Zong, Baorong Hou and Huiwen Tian

Polymers 2022, 14(5), 971; https://doi.org/10.3390/polym14050971 - 28 Feb 2022

Cited by 21 | Viewed by 3110

Abstract

The lack of river sand is becoming increasingly serious. In this study, we consider how to use sea sand to prepare innovative construction and building materials with excellent mechanical and durability properties. Sulphate corrosion causes expansion, cracking and spalling of concrete, resulting in [...] Read more.

The lack of river sand is becoming increasingly serious. In this study, we consider how to use sea sand to prepare innovative construction and building materials with excellent mechanical and durability properties. Sulphate corrosion causes expansion, cracking and spalling of concrete, resulting in the reduction or even loss of concrete strength and cementation force. In this paper, artificial seawater, sea sand, industrial waste, steel fiber and polycarboxylate superplasticizer were used to prepare ultra-high-performance polymer cement mortar (SSUHPC), and the sulphate corrosion mechanism was investigated. The strength and cementation force of mortar on the SSUHPC surface decreased and flaked off with the development of sulphate erosion, and the steel fiber rusted and fell off. A 3D model was established based on X-ray computed tomography (X-CT), and the results showed that SSUHPC maintained excellent internal structural characteristics despite severe sulphate erosion on the surface. Mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were adopted to investigate the sulphate corrosion mechanism of SSUHPC. We found a transition zone within 1–5 mm of the surface of SSUHPC. The Vickers hardness of mortar in this area was increased by 5~15%, and the porosity was reduced to 3.8489%. Obvious structural damage did not occur in this area, but a high content of gypsum appeared. UHPC prepared with seawater sea sand was found to have better sulphate resistance than that prepared with freshwater river sand, which supports the development and utilization of sea sand in concrete. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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14 pages, 5010 KiB  

Open AccessArticle

Mechanical Performance and Void Structure Change of Foamed Cement Paste Subjected to Static and Cyclic Loading under Plane Strain Conditions

by Zhen Zhang, Fengrui Rao, Guanbao Ye and Jiangting Liu

Materials 2022, 15(5), 1711; https://doi.org/10.3390/ma15051711 - 24 Feb 2022

Cited by 7 | Viewed by 1825

Abstract

Cement-based lightweight materials have received much attention recently in embankment backfill applications, the boundary of which is more close to a plane strain condition. To study the influence of plane strain condition on the behavior and void structure of cement-based lightweight material under [...] Read more.

Cement-based lightweight materials have received much attention recently in embankment backfill applications, the boundary of which is more close to a plane strain condition. To study the influence of plane strain condition on the behavior and void structure of cement-based lightweight material under cyclic loading, this paper conducted a series of compression tests on foamed cement pastes with densities of 700 and 900 kg/m³ subjected to static and cyclic loading under plane strain conditions. The X-CT technique was adopted to obtain the three-dimensional (3-D) void structures of the specimens before and after the loading tests. The results showed that the plane strain conditions yielded specimen compression strengths 30–50% higher than the unconfined conditions. The specimen integrity endured under load levels of less than 0.5, but failed after approximately 1000 cycles under a load level of 0.8, indicating that cyclic loading could accelerate the degradation of the specimena. The void structures of the specimens showed that the void volumes were featured bfatured an unimodal distribution with unimodal positions in a range of 0.1–0.2 mm³. The unimodal position became higher with the increasing cyclic load level. Slices of the specimens after static and cyclic loading tests suggested that cyclic load could easily lead to the rupture of voids that then merge into bigger voids and the connection of voids forming cracks. Full article

(This article belongs to the Topic Innovative Construction and Building Materials)

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