Green Blocks Made of Recycled Waste Phase II

In phase I, series of tests were carried out to determine to what extent feasible to make out of recycled construction waste, green and sustainable concrete blocks. The research concluded that the recycled fine aggregate (sand) affects the strength of the blocks drastically. At the end of phase I a recommendation was made to sieve and clean the recycled aggregate thoroughly to get rid of the high contents of the sand in the samples to be tested. The central objective of phase II trials is the testing of blocks made of recycled materials free of dust and sand contents. In order to test the extent of improvement in the strength and durability of the blocks, several mixes were designed. In this paper, 10 mixes of concrete and 100 specimens were prepared. In the mixes the fresh coarse and fine aggregate are replaced by 25%, 50%, 75%, and 100% of the recycled aggregate. The rest of the materials (OPC and recycled water) remain the same. All the mixes of the recycled coarse aggregate and recycled water achieved a good enhancement on the strength and durability of the blocks. Recycled sand still was found to be a limiting factor in this industry. The results presented show that the blocks made of recycled coarse aggregate and recycled water are reliable and of good strength and durability.