Geotechnical Characterization of Recycled Aggregates (RA) Comprising of Mixed Waste from Construction & Demolition (C&D) Plants

Abstract

India produces approximately 100 million tonnes of C&D waste per annum. Attempts are being made to separately process the C&D waste by segregating it from MSW stream. For this, C&D waste processing plants have been established in Delhi. About 1.15 million tons of C&D waste is annually processed in these plants. The bulk output from these plants is Recycled Concrete Aggregate (RCA) (10%), Recycled Aggregate (RA) (55%), and silt like fraction (below 0.075 mm) (35%). RCA and silt like fraction have reasonable demand in industry. RA comprising of mixed waste which has brickbats in highest proportion have low demand. It is coined as MRA (Mixed Recycled Aggregate) thereafter. Some areas in which gravel or sand-sized fraction of the MRA can be used are filters, drains, and backfill for embankments. The geotechnical characteristics of MRA from two C&D plants C&D P1 and C&D P2 were studied in laboratory for the sand-sized fraction. Grain size distribution, compaction, specific gravity, permeability, and shear strength test were done on MRA. The results have been compared with the locally available Badarpur Sand (BS). From the testing results it is observed that geotechnical properties like specific gravity, compaction, permeability, and shear strength of MRA are similar to BS. This study serves as a starting point for use of MRA to be used in various geotechnical application.