STRUCTURAL PERFORMANCE OF LIGHTWEIGHT REINFORCED BEAMS CONTAINING PERIWINKLE SHELLS AS COARSE AGGREGATE

Abstract

In this investigation, the strengths (compressive and flexural) of specimens (cubes and beams) cast from a mixture of cement, sand, periwinkle shells and water were determined. The variables are reinforcement volume fractions (0, 1%, 2%, 3%, 4% and 5%) and curing ages (7, 14 and 28 days). The reinforcement volume fraction is taken as a percentage of gross cross-sectional area of the beam. 0% reinforcement content is the control experiment. 150 mm cubes and 150 × 150 × 750 mm beams were cast using a mix proportion of 1:3½: 1 (cement:sand:periwinkle shells). The specimens were prepared in accordance with BS 1881 and cured in water at 21±1°C for the respective curing ages of 7, 14 and 28 days. Three specimens were tested at each curing age for each percentage of reinforcement. The results showed that the compressive and flexural strengths increase with increase in curing ages. The flexural strengths of the beams also increased with increase in reinforcement volume fractions up to 3% content, after which there was reduction in strength. This results show that the optimum reinforcement content is about 3% in reinforced concrete containing periwinkle shells as coarse aggregate compared with 4% for normal concrete. INTRODUCTION MATERIALS AND EXPERIMENTAL PROCEDURE TESTING OF SPECIMENS RESULTS AND DISCUSSION DEFLECTION FAILURE OF SPECIMENS CONCLUSIONS REFERENCES