Materials

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18 pages, 8668 KiB

Open AccessArticle

The Preparation and Properties of Ultra-High-Performance Concrete with Aeolian Sand: A Lab Study on the Effect of the Curing Method

by Yang Lv, Boyu Zhao, Jie Zhu, Chenhao He, Yunlu Ge, Yuanshuai Wu, Yanchao Zhu, Jianming Dan, Yang Zhou and Xiangguo Li

Materials 2025, 18(9), 2031; https://doi.org/10.3390/ma18092031 - 29 Apr 2025

Abstract

The utilization of aeolian sand (AS) as a substitute for river sand (RS) in ultra-high-performance concrete (UHPC) offers a sustainable solution to address natural sand resource shortages while enhancing AS utilization. This study systematically evaluates the influence of AS content (0–100% RS replacement [...] Read more.

The utilization of aeolian sand (AS) as a substitute for river sand (RS) in ultra-high-performance concrete (UHPC) offers a sustainable solution to address natural sand resource shortages while enhancing AS utilization. This study systematically evaluates the influence of AS content (0–100% RS replacement by mass) on the workability, mechanical properties, and microstructure of UHPC under different curing regimes. All mixtures incorporate 0.65% by volume of straight steel fibers to ensure adequate fiber reinforcement. The results reveal that the spherical morphology, smooth surface nature, and fine particle size of AS enhance the matrix fluidity and reduce the early autogenous shrinkage of UHPC. By employing steam curing at 90 °C for 2 d followed by standard curing for 7 d (M3), UHPC samples with a 60% and 80% AS substitution achieve a compressive strength of 132.4 MPa and 130.8 MPa, respectively; a flexural strength exceeding 18 MPa; a porosity below 10%; and a gel pore content exceeding 60%. The steel fiber reinforcement contributes significantly to the flexural performance, with the fiber–matrix interface quality maintained even at high AS replacement levels. These findings highlight the feasibility of AS as an alternative fine aggregate in UHPC. Full article

(This article belongs to the Special Issue Sustainability in Asphalt, Concrete and Pavement Materials: Design, Performance, and Characterization)

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16 pages, 4717 KiB

Open AccessArticle

Laboratory Investigation of Packing Characteristics and Mechanical Performance of Aggregate Blend

by Weixiao Yu, Yun Li, Zhipeng Liang, Jiaxi Wu, Sudi Wang and Yinghao Miao

Materials 2025, 18(9), 1953; https://doi.org/10.3390/ma18091953 - 25 Apr 2025

Viewed by 138

Abstract

Aggregates are the main material forming the skeleton structure of asphalt mixtures and are of great importance to resist external load for asphalt pavement. This study analyzed the packing characteristics and mechanical performance of aggregate blend to provide a reference for improving the [...] Read more.

Aggregates are the main material forming the skeleton structure of asphalt mixtures and are of great importance to resist external load for asphalt pavement. This study analyzed the packing characteristics and mechanical performance of aggregate blend to provide a reference for improving the bearing capacity of asphalt mixtures. The single-size, two-size, and multi-size aggregate blends were chosen to conduct the laboratory packing and California bearing ratio (CBR) tests. Six particle sizes were selected to design the single-size aggregate blends. Six size combinations were included and various mass ratios were considered for each size combination in the two-size aggregate blends. The multi-size aggregate blends were designed through the gradually filling method according to stone matrix asphalt with a nominal maximum particle size (NMPS) of 16 mm (SMA16) and dense asphalt concrete with an NMPS of 26.5 mm (AC25). The packing characteristics of the blends were quantified by the air voids and the percentage of contribution to the packing volume (PCPV). The mechanical performance of the blends was analyzed by the CBR value. The relationship between packing characteristics and mechanical performance was explored by data fitting. The results showed that the particle size and the size ratio have an effect on the packing characteristics and mechanical performance of aggregate blend. The smaller the particle size, the larger the air void of the blend. The blends composed of larger particles have better load bearing capacity than those composed of smaller particles. The larger the particle size ratio, the greater the air void of the blend and the weaker the load bearing capacity. The particles smaller than 1.18 mm and those smaller than 0.3 mm in AC25 mainly play a role in filling the voids and have little contribution to the load bearing. There is a certain correlation between the packing characteristics and mechanical performance of aggregate blend. Full article

(This article belongs to the Special Issue Sustainability in Asphalt, Concrete and Pavement Materials: Design, Performance, and Characterization)

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18 pages, 3404 KiB

Open AccessArticle

Study on Non-Destructive Testing Method of Existing Asphalt Pavement Based on the Principle of Geostatistics

by Duanyi Wang, Chuanxi Luo, Meng Fu, Wenting Zhang and Wenjie Xie

Materials 2025, 18(8), 1848; https://doi.org/10.3390/ma18081848 - 17 Apr 2025

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Abstract

In the context of the rapid advancement of reconstruction and expansion projects, there has been a significant increase in the demand for the inspection and evaluation of existing asphalt pavements. In order to enhance the efficiency and effectiveness of joint detection using 3D [...] Read more.

In the context of the rapid advancement of reconstruction and expansion projects, there has been a significant increase in the demand for the inspection and evaluation of existing asphalt pavements. In order to enhance the efficiency and effectiveness of joint detection using 3D ground-penetrating radar and falling weight deflectometers, this study investigates non-destructive testing methods for existing asphalt pavements based on geostatistical correlation principles. The relationship between crack rate and deflection is analyzed using group average values. The characteristic sections division method based on the crack rate guideline was realized. Research on the prediction method for deflection using Kriging interpolation has been conducted. Research has revealed that there is a positive correlation between the crack rate and the deflection index. The principle of the singularity index can be employed to divide characteristic sections. The falling weight deflectometer is capable of conducting targeted testing in accordance with characteristic sections. Furthermore, the superior performance of Kriging interpolation in predicting deflection compared with linear interpolation has been demonstrated. According to the Kriging interpolation principle, the detection interval of slow lane deflection should not be more than 100 m. Kriging interpolation on one way lane of matrix data has the best effect, and it can predict deflection using a limited amount of slow lane and hard shoulder data. This facilitates analysis of the changing trend of the deflection index in cases where detection conditions are constrained. This method is of great significance for grasping the true performance status of the existing asphalt pavement structure. Full article

(This article belongs to the Special Issue Sustainability in Asphalt, Concrete and Pavement Materials: Design, Performance, and Characterization)

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18 pages, 8797 KiB

Open AccessArticle

Comparison of Microwave Sensitivity and Performance of Asphalt Mastic with Various Steel Slag Powders

by Zeyu Geng, Weixiao Yu, Min Jiang and Yinghao Miao

Materials 2025, 18(6), 1348; https://doi.org/10.3390/ma18061348 - 19 Mar 2025

Viewed by 227

Abstract

Steel slag is a common solid waste, but it has good microwave absorbing ability. The poor microwave sensitivity of asphalt mixture limits the development of microwave maintenance for asphalt pavement. Therefore, it is significant to apply steel slag to asphalt pavement. This study [...] Read more.

Steel slag is a common solid waste, but it has good microwave absorbing ability. The poor microwave sensitivity of asphalt mixture limits the development of microwave maintenance for asphalt pavement. Therefore, it is significant to apply steel slag to asphalt pavement. This study analyzes the difference in the microwave sensitivity and performance between the asphalt mastics with blast furnace slag powder (BFSP), converter slag powder (CSP), refined slag powder (RSP), and limestone powder (LP). First, the chemical composition of BFSP, CSP, RSP, and LP is analyzed by X-ray diffractometer (XRD) and X-ray fluorescence (XRF) tests. Then, the micromorphology characteristics of the asphalt mastic with BFSP, that with CSP, that with RSP, and that with LP are studied using atomic force microscope (AFM) tests. Finally, the rheological properties of the four asphalt mastics are investigated through dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests. The results show that steel slag powder can effectively improve the microwave sensitivity of asphalt mastic. RSP and CSP can improve the anti-deformation ability of asphalt mastic. In addition, steel slag powders have an adverse effect on the low-temperature cracking resistance of asphalt mastic, but the creep strength and creep rate of asphalt mastic with steel slag powder are within a reasonable range. In general, steel slag powder as filler has great application potential in road engineering. However, it has a certain influence on the performance of asphalt mastic. It is necessary to carry out targeted selection in practical engineering. Full article

(This article belongs to the Special Issue Sustainability in Asphalt, Concrete and Pavement Materials: Design, Performance, and Characterization)

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17 pages, 9486 KiB

Open AccessArticle

Study on the Mechanical Properties of Modified Sludge Soil Based on an SM-C Modifier

by Jun Nie, Kai Zhang, Xiangyang Fan, Yixuan Zhang, Guoxu Wei, Xiangyong Yu and Wen Xu

Materials 2025, 18(3), 483; https://doi.org/10.3390/ma18030483 - 21 Jan 2025

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Abstract

The purpose of this study is to solve the problem of the harmless treatment of dredged silt and soil extraction during road construction in lake areas. The silt in the project area is used as the research material to evaluate its engineering applicability [...] Read more.

The purpose of this study is to solve the problem of the harmless treatment of dredged silt and soil extraction during road construction in lake areas. The silt in the project area is used as the research material to evaluate its engineering applicability as an improved filling material for the roadbed of the lake’s surrounding road. Through indoor pretreatment and a series of mechanical performance tests, including compaction tests, unconfined compressive strength tests (UCS), bearing ratio tests (CBR), triaxial compression tests (CU consolidated undrained), and consolidation tests, we obtained key mechanical parameters of modified sludge soil, such as maximum dry density, optimal moisture content, unconfined compressive strength, bearing ratio, shear strength, and compression characteristics. The research results show that with the increase in modifier dosage, the optimal moisture content of modified sludge soil increases, the maximum dry density decreases, and its compressive strength and shear strength significantly improve. The CBR value also meets the technical requirements of each layer of the roadbed. Specifically, after 7 days of curing, the compaction degree of 10% modified sludge soil can exceed 96%, the unconfined compressive strength reaches 0.819 MPa, the CBR value reaches 17.5, the cohesion measured by triaxial tests is 78 kPa, the internal friction angle is 27°, and it exhibits low compressibility. These findings provide new solutions for environmentally friendly treatment, resource utilization, and road engineering in river and lake sediments. Full article

(This article belongs to the Special Issue Sustainability in Asphalt, Concrete and Pavement Materials: Design, Performance, and Characterization)

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26 pages, 8502 KiB

Open AccessArticle

Enhancement of Microwave Heating Technology for Emulsified Asphalt Mixtures Using SiC-Fe₃O₄ Composite Material

by Sheng Xu, Wen Xu, Yixing Chen, Jiaqi Li and Yueguang Li

Materials 2024, 17(18), 4572; https://doi.org/10.3390/ma17184572 - 18 Sep 2024

Cited by 2 | Viewed by 1232

Abstract

The application of microwave heating technology can significantly enhance the water evaporation rate of emulsified asphalt mixtures post paving. To improve the microwave absorption and curing performance of these mixtures, SiC-Fe₃O₄ composite material (SF) was incorporated. This addition aims to [...] Read more.

The application of microwave heating technology can significantly enhance the water evaporation rate of emulsified asphalt mixtures post paving. To improve the microwave absorption and curing performance of these mixtures, SiC-Fe₃O₄ composite material (SF) was incorporated. This addition aims to enhance the microwave absorption efficiency and accelerate the curing process of emulsified asphalt mixtures under microwave heating. This study begins with an analysis of the microwave absorption principles pertinent to emulsified asphalt mixtures. Subsequently, the microwave heating temperature fields of ordinary emulsified asphalt mixture (EAM), SiC emulsified asphalt mixture (S-EAM), Fe₃O₄ emulsified asphalt mixture (F-EAM), and SiC-Fe₃O₄ emulsified asphalt mixture (SF-EAM) were simulated using COMSOL Multiphysics finite element software (COMSOL 6.2). The early strength variations in SF-EAM under different microwave heating durations were then examined through adhesion tests, leading to the proposal of a microwave heat curing process for SF-EAM. Finally, the wear resistance, water damage resistance, rutting resistance, and skid resistance of SF-EAM post-microwave curing were evaluated through wet wheel wear tests, wheel track deformation tests, and road friction coefficient tests. The results indicate that the optimal microwave heating time is 90 s, with the microwave absorption performance of the materials ranked as follows: EAM, S-EAM, F-EAM, and SF-EAM, from lowest to highest. The road performance of SF-EAM complies with specification requirements, and its wear resistance, water damage resistance, and rutting resistance are notably improved after microwave heating. Full article

(This article belongs to the Special Issue Sustainability in Asphalt, Concrete and Pavement Materials: Design, Performance, and Characterization)

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33 pages, 12647 KiB

Open AccessArticle

Design and Microwave Absorption Performance Study of SiC-Fe₃O₄ Emulsified Asphalt Mixture

by Xiangyu Jiang, Wen Xu, Yixing Chen and Jiaqi Li

Materials 2024, 17(16), 3935; https://doi.org/10.3390/ma17163935 - 8 Aug 2024

Cited by 1 | Viewed by 1274

Abstract

To address the challenges of slow curing speed and suboptimal microwave absorption during the paving of cold-mixed and cold-laid asphalt mixtures, this study introduces SiC-Fe₃O₄ composite material (SF) into emulsified asphalt mixtures to enhance microwave absorption and accelerate curing via [...] Read more.

To address the challenges of slow curing speed and suboptimal microwave absorption during the paving of cold-mixed and cold-laid asphalt mixtures, this study introduces SiC-Fe₃O₄ composite material (SF) into emulsified asphalt mixtures to enhance microwave absorption and accelerate curing via microwave heating. Initially, based on the maximum density curve theory, an appropriate mineral aggregate gradation was designed, and the optimal ratio of emulsified asphalt mixture was determined through mixing tests, cohesion tests, wet wheel wear tests, and load wheel sand adhesion tests. Subsequently, the influence of SF content on the mixing performance of emulsified asphalt mixtures was analyzed through mixing and consistency tests. Finally, the microwave absorption performance of the mixture was evaluated by designing microwave heating tests under different conditions, using temperature indicators and quality indicators. The experimental results indicate that when SF content ranges from 0% to 4%, the mixing performance of the emulsified asphalt mixture meets specification requirements. The dosage of SF, SF composite ratio, and microwave power significantly impact microwave absorption performance, whereas environmental temperature has a relatively minor effect. The optimal mix ratio for the emulsified asphalt mixture is mineral aggregate:modified emulsified asphalt:water:cement = 100:12.8:6:1. The ideal SF dosage is 4%, with an optimal SiC to Fe₃O₄ composite ratio of 1:1, and a suitable microwave power range of 600–1000 W. Full article

(This article belongs to the Special Issue Sustainability in Asphalt, Concrete and Pavement Materials: Design, Performance, and Characterization)

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14 pages, 4677 KiB

Open AccessArticle

Experimental Investigation of Water Vapor Concentration on Fracture Properties of Asphalt Concrete

by Yu Chen, Tingting Huang, Xuqing Wen, Kai Zhang and Zhengang Li

Materials 2024, 17(13), 3289; https://doi.org/10.3390/ma17133289 - 3 Jul 2024

Viewed by 1272

Abstract

The effect of moisture on the fracture resistance of asphalt concrete is a significant concern in pavement engineering. To investigate the effect of the water vapor concentration on the fracture properties of asphalt concrete, this study first designed a humidity conditioning program at [...] Read more.

The effect of moisture on the fracture resistance of asphalt concrete is a significant concern in pavement engineering. To investigate the effect of the water vapor concentration on the fracture properties of asphalt concrete, this study first designed a humidity conditioning program at the relative humidity (RH) levels of 2%, 50%, 80%, and 100% for the three types of asphalt concrete mixtures (AC-13C, AC-20C, and AC-25C).The finite element model was developed to simulate the water vapor diffusion and determine the duration of the conditioning period. The semi-circular bending (SCB) test was then performed at varying temperatures of 5 °C, 15 °C, and 25 °C to evaluate the fracture energy and tensile strength of the humidity-conditioned specimens. The test results showed that the increasing temperature and the RH levels resulted in a lower peak load but greater displacement of the mixtures. Both the fracture energy and tensile strength tended to diminish with the rising temperature. It was also found that moisture had a significant effect on the tensile strength and fracture energy of asphalt concrete. Specifically, as the RH level increased from 2% to 100% (i.e., the water vapor concentration rose from 0.35 g/m³ to 17.27 g/m³), the tensile strength of the three types of mixtures was reduced by 34.84% on average, which revealed that the water vapor led to the loss of adhesion and cohesion within the mixture. The genetic expression programming (GEP) model was developed to quantify the effect of water vapor concentrations and temperature on the fracture indices. Full article

(This article belongs to the Special Issue Sustainability in Asphalt, Concrete and Pavement Materials: Design, Performance, and Characterization)

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