ASSESSMENT OF STRENGTH PROPERTIES OF CONCRETE CONTAINING RECYCLED CONCRETE AGGREGATES FOR GREEN ENVIRONMENT

摘要

This paper was attempted to predict the compressive strength of Recycled aggregate concrete (RAC) at the ages of 28 and 90 days for various percentages of Recycled aggregate (RA) with Silica fume (SF). This work is to find the optimum replacement value of silica fume in RAC. For the findings of optimum value, 10 concrete mixes were prepared by replacing Natural coarse aggregate (NCA) with recycled coarse aggregates with 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50% of M30 Grade concrete. From this optimum replacement value of RCA, silica fume was added in 0, 5, 10, 15 and 20%. The water-to-cement ratio of 0.4 was maintained for all the mixes. At the initial stage, the workability test was performed for all the mixes. The mechanical properties like compressive strength, split tensile strength and flexural strength were examined by evaluating 28 and 90 days curing period of all concrete specimens. From the results, it was indicated that there is an acceptable limit of strength improvement while adding RA, whereas silica fume added, the compressive strength was increased up to the 15% replacement of SF. Thusly, Sustainable cement concrete (SCC) can be created by taking the above mix of RCA and silica fume as waste concrete without influencing the properties of concrete.