Sustainability and reducing environmental damage caused by CO2 emissions have become issues of interest to researchers in the construction sector around the world. Reducing the cement content in concrete by partially substituting it with by-products or waste falls within this field as the cement industry is responsible for 7% of global CO2 emissions. On the other hand, self-compacting concrete (SCC) is one of the special types of concrete that contains a large amount of powder (most of which is cement) to ensure its flow under the influence of its weight without separating its components. Therefore, to produce eco-friendly SCC, many researchers have replaced part of the cement with clay brick waste powder (CBWP) since brick units are among the most widely used building materials after concrete. Accordingly, this study aims to review previous research that included using CBWP in SCC. The effect of these wastes on the fresh, mechanical, durability and microstructural properties of cement was reviewed. Additionally, a comparison between the environmental impacts of SCCs with different CBWP contents has been conducted using the life cycle assessment (LCA) approach. It was found that the highest value of CBWP that can be used without negatively affecting the different properties of concrete is 10% by weight of cement. Moreover, regarding environmental impact, using CBWP as a substitute for cement reduces environmental damage, and the lowest environmental impact that can be achieved per strength unit (MPa) is 37.5%.

To study the influences of the nanomaterial upon the microstructure of the interfacial transition region of mortar that prepared with a composite binder comprising nanomaterial and to clarify its effect on the compressive strength improvement, in this study, the compressive strength, SEM analysis and XRD analysis were estimated for mortar containing different amounts of ZrO2, SiO2, Al2O3 and CaCO3 nanoparticles. Four different contents of each nanoparticles’ types were used as a partial replacement of cement with 1%, 1.5%, 3% and 5% by the weight of cement. Results manifested that the mortar compressive strength enhancement can be ascibed to the microstructure amelioration of the interfacial transition region. In addition, the XRD analysis and the SEM micrographs elucidated the formation of hydration compounds and the enhancement in bonding due to the existence of nanoparticles.

Cement production uses large quantities of natural resources and contributes to the release of CO2. In order to treat the environmental effects related to cement manufacturing, there is a need to improve alternative binders to make concrete. Accordingly, extensive study is ongoing into the utilization of cement replacements, using many waste materials and industrial. This paper introduces the results of experimental investigations upon the mortar study with the partial cement replacement. Fly ash, silica fume and glass powder were used as a partial replacement, and cement was replaced by 0%, 1%, 1.5%, 3% and 5% of each replacement by the weight. Compressive strength test was conducted upon specimens at the age of 7 and 28 days. Microstructural characteristic of the modified mortar was done through the scanning electron microscope (SEM) vision, and X-ray diffraction (XRD) analysis was carried out for mixes with different replacements. The tests results were compared with the control mix. The results manifested that all replacements present the development of strength; this improvement was less in the early ages and raised at the higher ages in comparison with the control specimens. Microstructural analysis showed the formation of hydration compounds in mortar paste for each replacement. This study concluded that the strength significantly improved by adding 5% of silica fume compared with fly ash and glass powder.

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In this study, polymer composites were manufactured with epoxy-based resin and wastes as a mineral additive. The wastes including a high content of silica (Silica fume, glass and fly ash) powder were used as fillers for an epoxy adhesive to improve its wear resistance properties. They were supplemented to mixes in various ratios via substituting the resin from 0 to 20% by weight. Tests of wear rate and hardness were conducted upon all-polymer composites at all fillers ratios. Results indicated that the epoxy hardness increased with increasing the filler addition. Consequently, the addition of wastes that include silica raised the wear resistance of polymer composites; nevertheless, it caused the composites harder materials. The wear rate decreased with increasing the silica fume, glass, and fly ash addition. In the case of fly ash addition, the minimum wear rate was at 15%, and after this percentage, the wear rate increased. However, in the case of glass addition, the minimum wear rate was at 10%, and after this percentage, the wear rate increased.