EXPERIMENTAL STUDY ON EFFECTIVE UTILIZATION OF DEMOLITION WASTE IN CONCRETE

Abstract

This experimental investigation concentrates on the use of coarse and fine pulverized concrete aggregates in control concrete (CM) mixtures. The intended characteristic strength of the concrete mixture is 25 MPa. The study examines six mixtures: Control Mix (CM) with natural aggregates, six formulations containing 20% total replacement of CRCA and FRCA in CM, namely CM, 20RAC0, 15RAC5, 10RAC10, 5RAC15 and 0RAC20, respectively. Each of the six combinations' fresh and aged qualities are evaluated. For a mixture containing 20% FRCA to obtain the desired slump of 100 ± 10 mm, an increased dosage of Superplasticizer (SP) is required. Control and partially aggregate-replaced concrete were tested for freshness (workability, density), mechanical properties (compressive, flexural strength), and durability (water penetration, permeability test). At each age of curing, the recycled refuse concrete characteristics were typically more severe than those of conventional concrete. However, as the curing time increased, the performance gap between standard and recycled concrete decreased. Moreover, when 20% CRCA and 20% FRCA were substituted for CM, the compressive strength decreased by 7.44% and 12.73%, respectively. As FRCA content increased, similar tendencies were observed in flexural tensile strength, water penetration depth, and permeability. The study demonstrates that RCA can be used in concrete with certain countermeasures to mitigate the negative effects of RAC, thereby assisting in C&D waste management and decreasing construction costs.