Replacement of Fine Aggregates by Recycled Construction and Demolition Waste in Pavement Quality Concrete

Abstract

Reusing of Construction and Demolition (C and D) waste is one among the numerous pathways that provide a wide convenience to avert waste materials from infiltrating the landfills and reduces the construction industry reliability on depleting natural resource supplies. Reinstating of fine aggregates in a concrete is studied with five incremental ratios such as 20, 40, 60, 80, and 100%. Since debris are coated with fine cementitious particles, the water absorption potential will be high. Hence, the beneficiation process is carried out by acid treatment process. After beneficiation, the water absorption capacity got reduced by 63%, soundness value improved by 29% and specific gravity increased by 13%. The aided aggregates were replaced for fine aggregates in M₃₀ and M₄₀ grade concrete. Results show construction and demolition waste as a possible natural aggregate replacement material with nominal changes in their physical characteristics. The changes in the strength properties were compared to control mix. From the study, it is found that an effective replacement of 31.97 and 20.05% of Recycled Fine Aggregate for M₃₀ and M₄₀ grade, respectively. The compressive strength is found to be for M₃₀—37.29 and M₄₀—48.06 N/mm², the flexural strength is found to be for M₃₀—10.22 and M₄₀—13.36 N/mm² and the fatigue strength for M₃₀—372,356, 89,562, 48,249, 23,732 and 4955 no. of cycles and M₄₀—873,925, 128,890, 73,664, 32,976, and 7112 no. of cycles for stress ratio 0.55, 0.60, 0.65, 0.70, and 0.75, respectively.