Search Results (21)

Recently, electromagnetic wave (EMW)-absorbing materials have obtained increasing attention for both military and civil applications. This study adopted the powder sintering method and the concept of recycled wastes in fabricating functional ceramic foam (CF). Firstly, a ceramic green body composed of pulverized granite residues, waste glass, and a foaming agent was sintered. The influence of the sintering temperature and SiC addition on CF was investigated, and then surface graphitization post-treatment of CF was performed as well. The truly enhanced compressive strength and EMW-absorbing property of surface graphitization ceramic foam (SG-CF) with a homogeneous porous structure was realized in the present work, which is promising as a candidate in EMW absorption systems. Full article

This study aims to incorporate building and demolition waste, including lime and crushed granite, as partial alternatives for cement and fine aggregates, respectively, and to devise a plan to reduce their environmental effect resulting from their extensive prevalence in substantial amounts. The use of lime in paste, mortar, and concrete has become a common practice to regulate the environment, save resources, and improve performance in various settings. The first stage of this study investigated the effects of replacing different proportions (0%, 15%, 25%, 35%, and 50%) of lime powder with cement on the physical and mechanical properties of mortar specimens over 7, 28, and 90 days. The next phase of the research examined the impacts of substituting varying quantities (ranging from 10% to 100%) of granite powder in 15 different mixes, while keeping a consistent water-to-binder ratio of 0.45. The last part of the study consisted of an examination of data from previous research on cement mortar and lime-modified cement mortar. This included testing on flowability, standard consistency, setting time, flexural strength, and compressive strength. The acquired data underwent a statistical analysis, which resulted in the development of equations that may predict the mechanical characteristics of changed cement mortar mixes. These equations also highlight the impact of certain physical qualities on compressive and flexural strength. Full article

Engineered geopolymer composite (EGC) is a high-performance material with enhanced mechanical and durability capabilities. Ground granulated blast furnace slag (GGBFS) and silica fume (SF) are common binder materials in producing EGC. However, due to the scarcity and high cost of these materials in some countries, sustainable alternatives are needed. This research focused on producing eco-friendly EGC made of cheaper and more common pozzolanic waste materials that are rich in aluminum and silicon. Rice husk ash (RHA), granite waste powder (GWP), and volcanic pumice powder (VPP) were used as partial substitutions (10–50%) of GGBFS in EGC. The effects of these wastes on workability, unit weight, compressive strength, tensile strength, flexural strength, water absorption, and porosity of EGC were examined. The residual compressive strength of the proposed EGC mixtures at high elevated temperatures (200, 400, and 600 °C) was also evaluated. Additionally, scanning electron microscope (SEM) was employed to analyze the EGC microstructure characteristics. The experimental results demonstrated that replacing GGBFS with RHA and GWP at high replacement ratios decreased EGC workability by up to 23.1% and 30.8%, respectively, while 50% VPP improved EGC workability by up to 38.5%. EGC mixtures made with 30% RHA, 20% GWP, or 10% VPP showed the optimal results in which they exhibited the highest compressive, tensile, and flexural strengths, as well as the highest residual compressive strength when exposed to high elevated temperatures. The water absorption and porosity increased by up to 106.1% and 75.1%, respectively, when using RHA; increased by up to 23.2% and 18.6%, respectively, when using GWP; and decreased by up to 24.7% and 22.6%, respectively, when using VPP in EGC. Full article

The sourcing of raw materials is becoming an increasingly concerning issue for the European Union, which is adopting a series of strategies aimed at mitigating the dependence on third countries for procurement. The supply of feldspars, for instance, which is significant within the ceramic industry, raises concerns due to heavy reliance on third countries. Therefore, it is imperative to identify potential alternative sources for procurement, including the recycling of waste from the extraction of ornamental granite rocks enriched in such minerals. The Sardinia region in Italy, once a global leader in granite extraction, has now witnessed a significant reduction in production due to intense competition worldwide, resulting in severe economic repercussions. Additionally, traces of this period remain in the territory in the form of enormous quantities of extraction waste, defacing the landscape and posing potential environmental issues. This study is part of a broader research initiative aimed at identifying a physical process to concentrate rare earth element (REE) minerals from granite waste in a quarry located in Buddusò, Sardinia. The specific objective of this study is to analyze the whole rock composition, crushing powder, and the diamagnetic by-products generated by gravity and magnetic separations to identify potential applications for their use. Full article

The circular economy seeks to better use materials and minimize waste generation. This article evaluated the use of granite rock powder, a mining residue, as an adsorbent for the Basazol Yellow 5G (BY5G) dye and the reuse of the residue generated by the by treating this effluent in construction products. Characterization of the adsorbent material by N₂ physisorption indicated a surface area of 1514 m² g⁻¹. Energy-dispersive spectrometry (EDS) and X-ray diffraction (XRD) confirmed the presence of silica in the sample and the absence of amorphous halos. The kinetic study showed a removal of approximately 98% at 298 K, and the pseudo-second-order model obtained the best fit. The adsorption isotherm satisfied the Langmuir model and was consistent with the L-type isotherm. The negative value of the Gibbs energy (ΔG°) and the positive value of the enthalpy (ΔH°) indicate that the process is spontaneous and endothermic. The activation energy (Ea) indicates the occurrence of chemical adsorption. The desorption rate was low for the adsorbate, demonstrating the possibility of using residual adsorbent material as a filler in mortar and concrete. The material did not exhibit pozzolanic characteristics and, even after adsorption, it showed favorable results when replacing 10% of the cement with GRP viable for use in civil construction even after the adsorption process. Full article

The purpose of this study is to examine the effects of partially replacing cement with a blend of marble waste powder (MWP) and granite waste powder (GWP) in mortar, with the goal of reducing the environmental harm caused by cement. The investigation included an analysis of the distinctive properties of the two waste powders individually, as well as initial tests with various ratios to determine the optimal combination that yields the highest strength. It was observed that a 50% MWP to 50% GWP blend produced the most substantial strength. Subsequently, the effect of partial replacement of cement with the blend of marble and granite waste powder (MGWP) at various increments of 5%, ranging from 0% to 30%, was evaluated by subjecting the mortar to numerous tests to assess its workability, physical, mechanical, durability, and microstructural properties. The analysis of the employed waste powders confirmed that the GWP can be classified as a natural pozzolan material belonging to Class N. As the proportion of MGWP increased, the workability of the mortar mixes decreased. However, incorporating MGWP up to 15% resulted in enhancements in bulk density, compression strength, and homogeneity, with the best performance observed at a 10% MGWP content. Microstructure analysis confirmed that the addition of MGWP enhanced the bonding of C–S–H and C–H, leading to a denser morphological structure in the mixes, particularly at a 10% MGWP content. The utilization of MGWP not only significantly reduced the carbon footprint associated with cement production but also fostered sustainability. Full article

This research was conducted to evaluate the influence of waste granite powder (WGP) and polypropylene (PP) fibers on the performance of M35-grade pavement quality concrete (PQC). WGP was mixed in PQC as replacement for cement and was varied from 0% to 25%. The pozzolanic concert of WGP was examined by the strength activity index. The performance of PP fibers in PQC was assessed after the addition of fibers from 0.25% to 1.25% by volume of concrete. The mechanical properties of PQC were evaluated including the compressive strength, flexural strength, and various durability related properties such as the acid attack, absorption test, sorptivity test, and chloride penetration depth test. The results showed that PQC blended with WGP enhanced the strength slightly up to the replacement level of 15%. The addition of PP fibers rooted the reduction of the slump value; however, it improved the mechanical properties up to the presence of 0.5% PP fibers in PQC. The relationship between the compressive strength and flexural strength of WGP blended with PP fiber-reinforced PQC was established. Full article

The article assesses comparative analyses of some selected machine-learning algorithms for the estimation of the subsurface tensile strength of cementitious composites containing waste granite powder. Any addition of material to cementitious composites causes their properties to differ; therefore, there is always a need to prepare a precise model for estimating these properties’ values. In this research, such a model of prediction of the subsurface tensile strength has been carried out by using a hybrid approach of using a nondestructive method and neural networks. Moreover, various topologies of neural networks have been evaluated with different learning algorithms and number of hidden layers. It has been proven by the very satisfactory results of the performance parameters that such an approach might be used in practice. The errors values (MAPE, NRMSE, and MAE) of this model range from 10 to 12%, which, in the case of civil engineering practice, proves that this model is sufficient for being used. This novel approach can be a reasonable alternative for evaluating the properties of spacious cementitious composite elements where there is a need to analyse not only the compressive strength but also its subsurface tensile strength. Full article

The main objective of this work is to recycle unwanted industrial waste in order to produce innovative nanocomposites with improved mechanical, tribological, and thermal properties for use in various industrial purposes. In this context, powder metallurgy (PM) technique was used to fabricate iron (Fe)/copper (Cu)/niobium carbide (NbC)/granite nanocomposites having outstanding mechanical, wear and thermal properties. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) examinations were used to investigate the particle size, crystal size, and phase composition of the milled samples. Additionally, it was investigated how different volume percentages of the NbC and granite affected the sintered specimens in terms of density, microstructure, mechanical and wear properties, and coefficient of thermal expansion (CTE). According to the findings, the milled powders included particles that were around 55 nm in size and clearly contained agglomerates. The results showed that the addition of 4 vol.% NbC and 8 vol.% granite nanoparticles caused a reduction in the Fe–Cu alloy matrix particle sizes up to 47.8 nm and served as a barrier to the migration of dislocations. In addition, the successive increase in the hybrid concentrations led to a significant decrease in the crystal size of the samples prepared as follows: 29.73, 27.58, 22.69, 19.95 and 15.8 nm. Furthermore, compared with the base Fe–Cu alloy, the nanocomposite having 12 vol.% of hybrid reinforcement demonstrated a significant improvement in the microhardness, ultimate strength, Young’s modulus, longitudinal modulus, shear modulus, bulk modulus, CTE and wear rate by 94.3, 96.4, 61.1, 78.2, 57.1, 73.6, 25.6 and 61.9%, respectively. This indicates that both NbC and granite can actually act as excellent reinforcements in the Fe alloy. Full article

Clay brick and granite waste are part of the waste generated by construction and demolition activities. The amount of these wastes generated is enormous, but on the one hand, they can be used as a raw material for cement mixtures; thus, it is important to find ways to utilize them efficiently. In this study, clay brick and granite waste were crushed and screened into two size fractions (0.15–2.36 mm for sand replacement and smaller than 0.15 mm for cement replacement), and a total of four different forms of recycled materials were obtained (recycled brick aggregate, recycled brick powder, recycled granite aggregate and recycled granite powder) and used in cement mortar. Various properties (workability, mechanical strength and drying shrinkage) of the mortars were assessed according to standardized test methods. The results showed that the various material forms had different effects on the various properties of cement mortar. At replacement ratios of 10% and 20%, recycled granite showed better workability when used as powder, whereas recycled brick used as aggregate had higher workability. In common, using recycled brick and recycled granite in the form of aggregate was advantageous for the strength development of mortar, while using them in the form of powder helped to mitigate drying shrinkage. Full article

Granite is a well-known building and decorative material, and, therefore, the amount of produced waste in the form of granite powder is a problem. Granite powder affects the health of people living near landfills. Dust particles floating in the air, which are blown by gusts of wind, can lead to lung silicosis and eye infections, and can also affect the immune system. To find an application for this kind of waste material, it was decided to study the effect of partially replacing cement with waste granite powder on the properties of fresh and hardened mortars intended for masonry applications. The authors planned to replace 5%, 10%, and 15% of cement with waste material. Series of mortar with the addition of granite powder achieved 50% to 70% of the compressive strength of the reference series, and 60% to 76% of the bending strength of the reference series. The partial replacement of cement with the granite powder significantly increased the water sorption coefficient. The consistency of the fresh mortar, and its density and water absorption also increased when compared to the reference series. Therefore, Granite powder can be used as a partial replacement of cement in masonry mortars. Full article

The main objective of this study is to investigate the effect of granite waste powder on the behavior of compacted clay soil in both field and laboratory environments. Samples were collected from clay soil exposed at Karak, Khyber Pakhtunkhwa, Pakistan. The sampled soils contain kaolinite, illite, and montmorillonites. The samples were mixed with various quantities, i.e., 10%, 20%, 30%, and 40% by weight of granite waste powder collected from various stone industries in district Mansehra, Khyber Pakhtunkhwa, Pakistan. They were then subjected to a variety of geotechnical testing in both the laboratory and the field, following the standard ASTM procedures. The results show that mixing with granite-cutting waste enhances the quality of the soil in both the field and laboratory settings by increasing its bearing capacity (BC), dry density (DD), California-bearing ratio (CBR), unconfined compressive strength (UCS), penetration resistance, and angle of internal friction and by reducing the optimum moisture content, cohesion, porosity, void ratio, and saturation potential. The resulting improvement is mainly due to the stronger, denser, and less hydrophilic character of the constituents of the added rock powders than the raw soil. It is observed that adding 40% granite waste powder produces the best outcome. However, there is a significant difference in the magnitude of the impact on soil quality between the laboratory and field testing. Owing to differences in the testing environment, soil volume, and compaction effort and energy, the amount of improvement is higher in laboratory testing than in field testing. Full article

Granite powder (stone powder), a waste product generated from stone quarries, is increasingly being reused in cement-treated clays. The particle size of stone powders affects the cement-clay reaction by either increasing or reducing the unconfined compressive strength (UCS). This study investigated this phenomenon by separating stone powder from the same batch at the quarry into five particle sizes (A, B, C, D and E: 106–75 µm, 40–75 µm, 20–40 µm, <20 µm and 106–<1 µm, respectively). Flow value, fall cone, UCS and thermogravimetry-differential thermal analysis (TG-DTA), X-ray fluorescence, electrical conductivity and NaOH digestion tests were conducted. It was discovered that stone powder had an amorphization rate of up to 1.45% (14.5 mg/g of amorphous silica); hence, it was pozzolanic. However, the amorphousness varied with the particle size of the material in the order of D > E > C > B > A, which translated into UCS variation in the same order. Stone powders D and E played two roles in UCS development, i.e., nucleation of cementitious products and reaction with Ca(OH)₂ to increase the UCS higher than the control sample. Linear regression equations determined the minimum concentration of amorphous silica for a UCS increment as 9.4 mg/g. Full article

Industrial waste such as Ground Granulated Blast-Furnace Slag (GGBS) and Granite Waste Powder (GWP) is available in huge quantities in several states of India. These ingredients have no recognized application and are usually shed in landfills. This process and these materials are sources of severe environmental pollution. This industrial waste has been utilized as a binder for geopolymers, which is our primary focus. This paper presents the investigation of the optimum percentage of granite waste powder as a binder, specifically, the effect of molar and alkaline to binder (A/B) ratio on the mechanical properties of geopolymer concrete (GPC). Additionally, this study involves the use of admixture SP-340 for better performance of workability. Current work focuses on investigating the effect of a change in molarity that results in strength development in geopolymer concrete. The limits for the present work were: GGBS partially replaced by GWP up to 30%; molar ranging from 12 to 18 with the interval of 2 M; and A/B ratio of 0.30. For 16 M of GPC, a maximum slump was observed for GWP with 60 mm compared to other molar concentration. For 16 M of GPC, a maximum compressive strength (CS) was observed for GWP with 20%, of 33.95 MPa. For 16 M of GPC, a maximum STS was observed for GWP, with 20%, of 3.15 MPa. For 16 M of GPC, a maximum FS was observed for GWP, with 20%, of 4.79 MPa. Geopolymer concrete has better strength properties than conventional concrete. GPC is $13.70 costlier than conventional concrete per cubic meter. Full article

This paper explores the feasibility of employing drinking water treatment sludge (WTS) mixed with soils, lime, or rock powder in geotechnical applications, as well as discusses the sustainability of the approach based on experimental results, aiming at the beneficial reuse of waste and the preservation of natural geomaterials. The selected materials were two soils largely used in earthworks, two WTSs, a high purity calcium hydrated lime, and rock powder from a granitic–gneissic quarry, all occurring in São Paulo State, Brazil. The mixtures were chemically, mineralogically, and geotechnically characterized, and the geotechnical properties permeability, shear strength, and deformability were investigated. Soil-WTS mixtures showed hydraulic conductivity (10⁻¹⁰–10⁻⁶ m/s, depending on soil and WTS), effective cohesion (10–30 kPa), friction angle (34°–40°), undrained strength (>50 kPa), and compression index (0.1–0.4) compatible with those of soils usually employed in earthworks. Lime:WTS and rock powder:WTS mixtures achieved 50 kPa undrained strength for WTS contents lower than 24% and 8%, respectively, and could be used as daily and intermediate covers of waste landfills, as well as in other applications with low soliciting stresses. The possibility of WTS being pumped instead of transported by trucks was analyzed in the light of results from rheological tests. Full article