Green blocks made of recycled waste

摘要

Recycled aggregate (RA) is widely used in construction industry. These uses include road sub-base pipes bedding and back filling. This research shows the feasibility of producing sustainable blocks made of recycled materials. In this paper, the combined effects of recycled aggregate (RA) and recycled water (RW) on strength and durability of concrete blocks are presented and discussed. The test program involves the preparation of moderate strength concrete blocks out of recycled water and recycled aggregate obtained from construction waste. Twenty one mixes of concrete and 156 specimens were prepared. In the mixes 25%, 50%, 75%, and 100% of the fresh aggregate and water were replaced by recycled aggregate and recycled water. The effect of recycled aggregate and water on axial and flexural strength was found to be moderate but had a significant effect on durability. To enhance the durability and lower the carbon footprint (1000 kg/m3) of the recycled concrete mix, the OPC was replaced by GGBS. Three replacements, 25%, 50%, and 75% of OPC were tested. All the mixes achieved a reasonable enhancement on the strength and durability of the blocks. In general making blocks of recycled materials is feasible. GGBS replacement is recommended for future work to enhance the strength and durability.