Recycled Aggregate as Coarse Aggregate Replacement in Concrete Mixes

ABSTRACT: Utilization of Recycled Aggregate in concrete has been employed due to awareness of society in natural resources protection. The application of Recycled Aggregate (RA) as coarse aggregate in concrete mixes has been iniated as to make use effectively the waste materials. However the concrete using Recycled Aggregate or familiarly known as Recycled Aggregate Concrete has obtained lower performance compared to concrete using Natural Aggregate. Thus, in this research, Micronised Biomass Silica (MBS) which is produced from rice husk has been used for improving the performance of Recycled Aggregate Concrete. Concrete specimens containing various percentages of Recycled Aggregate (0%, 25%, 50%, 75%,100%) and MBS (0%, 4%, 8%, 12%) has been prepared for laboratory works. From the laboratory works it was found that after 28 days, 12 % of MBS has the ability to enhance the performance of 100 % Recycled Aggregate in concrete for compressive strength up to 17.20 % and reduce the water permeability coefficient and water penetration up to 47.10 % and 7.5 % respectively. Thus it can be stated that RAC containing MBS has better performance compared to RAC without MBS