Mechanical Characteristics of Recycled Concrete Aggregates as Backfill Material

摘要

The present study explores the feasibility of using recycled aggregates as backfill materials in Oman. Concrete waste was collected from the demolished sites. A small-scale ball-mill was manufactured to recycle the aggregates from concrete. A series of tests were conducted on the mixes of natural aggregates (NA) and recycled aggregates (RA). According to the test results, the maximum dry density can be achieved at optimum moisture content of 7.9% for NA and 10.5% for RA. As per, aggregate impact value test both NA and RA were classified as strong. The measured S-wave velocity for NA as well as RA mixes was in range of 500 to 550 m/s. However, the mean strength NA mix was 912kPa and that of RA mix was 532kPa. The plot of strength and S-wave velocity elucidated that the difference in strength is inferred to the difference in dry density of specimens. The delineated strength is mainly the function of angle of internal friction because both the mixes were granular soils. The results generated from the present study will provide the useful information on the design parameters for the application of recycled aggregates as backfill material.