Effects of Using Green Concrete Materials on the CO 2 Emissions of the Residential Building Sector in Egypt

Increasing the rate of construction material consumption has caused significant environmental problems in recent decades, especially the production of ordinary Portland cement (OPC), which has been associated with 8% of the world’s human CO 2 emissions and is considered the leading binder of concrete. This study aims to investigate the effects of substituting conventional concrete (CC) material with green concrete (GC) in the non-structural concrete works of a residential building in New Borg El-Arab City, Egypt. It attempts to establish what the effects are of using GC on cement, natural aggregates, and CO 2 emissions in the design phase. By using a design-based solution (DBS), we began with redesign, reduce, reselect, reuse, and recycle strategies to find an optimal solution for applying recycle aggregate concrete (RAC) as a replacement material in selected building parts, such as the internal floor, external sidewalk, entrance steps, and wall boundary. AutoCAD software and 3Dmax were used to modify the original design and obtain two design references with four different scenarios. Comparative analyses were applied to investigate the effects of different concrete materials. The results show a reduction of about 19.4% in cement consumption in terms of the total concrete of the building and a 44.5% reduction in CO 2 emissions due to the reduction of cement in specific building parts. In addition, this solution decreased natural coarse aggregate (NCA) consumption by 23.7% in the final concrete. This study recommends that GC materials close the loop of cementitious material consumption to reduce environmental impacts and achieve sustainability in the Egyptian building sector.