The aim of this study is to assess the possibility of utilizing waste marble dust (WMD) as a partial cement substitution in air-cured mortar (ACM). Three different levels of cement replacement were analyzed: 5%, 10% and 15% by cement weight. The specimens were manufactured in a local laboratory at an air temperature of 22 ± 2 °C and a humidity equal to 20 ± 1%. The chemical and physical properties of ordinary Portland cement and WMD has been found to be the most crucial parameters. A variety of macroscopic tests, such as apparent density, porosity and compressive strength, were proposed in order to explain the effect of utilizing the WMD on the ACM. To confirm the results of the macroscopic properties, thorough microstructural analysis using scanning electron microscopy (SEM) was performed. The obtained results of this study indicate that replacing cement with WMD affects the physical and mechanical properties of air-cured mortar. The apparent density and compressive strength decrease while the porosity increases.

The goal of this article is to study the effect of curing conditions on the properties of cement-based composites blended with waste marble dust (WMD). WMD was added to cement-based composites with different ratios of replacement, and two of the most commonly used curing conditions were applied. Half of the composites were cured in water at a temperature of 20 ± 1°C, and the other half of the composites were cured in air at a temperature equal to 22 ± 2°C and relative humidity (RH) equal to 20 ± 1%. To achieve the goals of the study, the composites were tested after 3 days, 7 days, 28 days, and 65 days of curing for their apparent density (ϒ_ad), porosity (p_m) and compressive strength (f_cd). Finally, the obtained macroscopic observations were validated using scanning electron microscopy. It was found that the water curing conditions were beneficial for the cement-based composites and gave satisfactory results compared with the air-curing conditions.

This paper presents an experimental study on the assessment of the cement-based materials properties made with marble powder (MP) at different replacement ratios (0%, 5%, 10%, and 15%) of cement by using the ultrasonic pulse velocity (UPV) test. The used MP has a Blaine fineness similar to that of Portland cement. The physical and the chemical characteristics of Portland cement and MP were determined. To determine the UPV values, cubic specimens (50 × 50 × 50 mm3) of cement paste and mortar were prepared and cured either in air at a temperature equal to 22 ± 2 °C and relative humidity equal to 20 ± 1%, or in water at a temperature equal to 20 ± 1 °C. The experimental tests including the UPV, the compressive strength (fcd), and the apparent density (ϒad) were conducted at 3, 7, 28, and 65 days, the relationship between each of these parameters were presented. Additionally, economic performance of cement and waste MP used in this study was performed. The results show that the use of MP as partial replacement of cement causes a decrease in the compressive strength and apparent density in both curing conditions. In addition, the results show a good relationship between the destructive test and non-destructive test adopted by UPV.

This paper examined the effect of marble powder (MP) on air-cured cement-based materials when subjected to sulfuric acid (H₂SO₄) attack. Four MP replacement levels were tested: 0%, 5%, 10%, and 15% by weight of cement. The prepared samples were cured for 90 days prior to being exposed to H₂SO₄. Macroscopic tests for apparent density and compressive strength along with microstructural characterization using X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to determine the effect of MP on the properties of the materials. The Rietveld method was used to analyze the amounts of different crystalline phases and amorphous calcium silicate hydrate (C-S-H). The obtained results indicate that 5% MP in air-cured cement -based materials exhibited the best behavior with acceptable resistance to acid attacks. This level of MP replacement was found to optimize the filler effect, improve the hydration process, and enhance the matrix density, which in turn reduces the permeability of the material and increases acid resistance. This is attributed to the balanced contribution of MP to phase formation, particularly calcite, which helps to counteract acid-induced dissolution, while also preserving the stability of C-S-H phases. This study provides a new perspective of the role of MP in influencing phase content (crystalline and amorphous phases) and their possible impacts on macroscopic properties such as apparent density and compressive strength. MP behaved as a filler, to improve hydration and resistance to acid attacks. Additionally, using MP as a replacement for ordinary Portland cement (OPC) offers a sustainable alternative by reducing waste and promoting the recycling of marble industry by-products, thereby contributing to environmental sustainability. It is recommended that, 5% MP is the optimal replacement content to enhance durability and mechanical properties in air-cured cement-based materials in aggressive environments, as it is both practical and achievable for infrastructure to be subjected to the aggressive environment.