Studies on the effect of recycled concrete aggregates on concrete with mixed fibre and pozzolans

Abstract

The steel fibre and synthetic fibres can entirely replace traditional rebars in concrete under specific circumstances like industrial floorings, which are subjected to dynamic loading due to movement of heavy machinery. The large scale availability of Recycled Concrete Aggregates (RCA) can be utilized to make these concrete floors. These are generally substantiated by laboratory test to ensure that the performance criteria are satisfied. The usefulness of combining RCA in high strength quaternary blended mixed fibre reinforced concrete (h-MFR-QB) in resisting compression, flexure, split tensile strength, and repetitive low-velocity drop-weight impact was evaluated in an experimental programme. The experiments were carried out on three different groups of specimens. Fly ash, micro silica, Nano silica, hooked end steel fibres, and PP fibres were used in each group. The advantages of both fibres were accomplished for efficient concrete using a volume fraction of 0.2% and 1% of PP and steel fibres, respectively, to offset the detrimental effect of adding RCA. When compared to non-fibrous concrete, the h-MFR-QB concrete material specimens exhibit a strong resistance to compression, flexure, split tensile strength, and repetitive low-velocity drop-weight impact drop-weight impact.