Testing of Strength of Recycled Waste Concrete and Its Applicability

This paper gives results of studies undertaken to assess suitability of construction demolition as coarse aggregate in new concrete production. Three sets of concrete materials considered are fresh concrete (FCM), waste concrete (WCM), and waste concrete strengthened with admixtures (SWCM). Various mixes were prepared for carrying out the research by varying the proportions of cement, sand, and aggregates. All mixes were designed for characteristic strength ( fck ) of M20. The compressive strength of concretes was tested in laboratory after 3, 7, and 28 days. The specimens used for testing include cubes, cylinders, and flexural beams. The influence of admixtures on the strength of waste concrete was examined. The compressive strengths of FCM, WCM, and SWCM are compared and the results show that there is not much difference in the strengths of FCM and SWCM after 28 days. For this reason, this study recommends the recycling of waste concrete as an aggregate material in the production of new concrete.