INFLUENCE OF AGGREGATES TREATMENT ON PROPERTIES OF RECYCLED AGGREGATE CONCRETE

The depletion of natural sand and natural aggregate encourage to use alternative raw material which deposits close to large urban centers. Waste materials produced from either demolished concrete Structures or from industrial precasting of concrete members, are the potential sources for Recycled Concrete Aggregates and can possibly be employed for producing new cement-based composites, such as ecological concretes or mortars the comparative result of the experiments of fresh and hardened concrete with different replacement ratios of natural aggregate with recycled coarse aggregate and recycled fine aggregate. Four types of concrete mixtureswere tested: concrete made completely with natural aggregate as a control concrete and three other types of concrete made with recycled fine aggregate and treated recycled coarse aggregate. In this study replacement of Natural aggregate is restricted up to 30% of coarse recycled aggregate. Moreover, fine aggregates replaced in 50% and 100% to Fine recycle aggregates. There are three types of treatment under consideration for recycled aggregate (1) Abrasion of Recycled Aggregate (2) Cement slurry coating of Recycled Aggregate (3) Chemical immersion of Recycled Aggregate. The results indicate that concrete produced with higher percentage of fine Recycled Aggregate shows less workability in comparison to control concrete. It was found that strength of Recycled Coarse Aggregate concrete has equivalent or higher performance to concrete made with natural aggregates, for corresponding 28-day design strengths. Abrasion treatment to Recycled aggregate gives better result in all among treatments. The replacement ratio of coarse RA and fine RA is not affected in satisfactory performance recycled aggregate concrete results.