Hardened Properties Of Brick Aggregate Concrete Using Coconut Shell as A Partial Replacement Of Coarse Aggregate

Abstract

The study was conducted to develop brick aggregate concrete including coconut shell as a partial replacement of coarse aggregate. Different coconut shell brick aggregate concretes (CSBACs) were prepared using 0–15% coconut shell aggregate (CSA) as a partial replacement of brick coarse aggregate and considering the water to cement (w/c) ratios of 0.45, 0.50 and 0.55 at the constant mix ratio of 1:1.5:3 (cement: fine aggregate: coarse aggregate) by bulk volume. CSBACs were tested to determine the major fresh and hardened properties. The fresh properties of CSBACs examined were workability and wet density. Among the hardened properties of CSBACs investigated, compressive strength was determined at the ages of 28,56 and 90 days whereas splitting tensile strength, flexural strength, modulus of elasticity, Poisson’s ratio, and dry density were examined at the age of 28 days only. Test results revealed that the workability of CSBAC was lesser than that of the control concrete, but the decrease was lower with higher CSA content whereas the wet density of CSBAC decreased progressively with the increased amount of CSA. The compressive strength, splitting tensile strength, and flexural strength of CSBAC at 28 days decreased significantly for 10% and 15% CSA contents. However, at the ages of 56 and 90 days, the rate of gain in the compressive strength of CSBAC was higher for the w/c ratio of 0.50. The dry density and modulus of elasticity of CSBAC decreased with the increased amount of CSA for all replacement levels of brick aggregate whereas its Poisson’s ratio was higher than that of the control concrete at 28 days. Based on the data obtained, the correlations for the mechanical properties of CSBAC were sought. Strong correlations between most of the mechanical properties of CSBAC were observed in this thesis.