Mechanical characterisation of sustainable fibre-reinforced lightweight concrete incorporating waste coconut shell as coarse aggregate and sisal fibre

Abstract

The construction industry is largely dependent on concrete as a construction material. The aggregate occupies a major volume of concrete. However, the continuous extraction of granite rock for coarse aggregate leads to the increase in demand of natural resources of future generations. In this study, coconut shell, an agricultural waste, is used to replace conventional aggregate in concrete for producing coconut shell lightweight concrete. To enhance the weak mechanical characteristics of lightweight concrete, various contents of sisal fibre at 1%, 2%, 3% and 4% have been added on the basis of the binder’s weight. Mechanical properties, such as compressive strength, split tensile strength, flexural strength, elastic modulus and impact resistance, were examined. Results showed that the compressive strength increased by up to 6% when 3% fibre was added. An improvement in split tensile strength of 14%, flexural strength of 11% and modulus of elasticity of 6% was observed when a maximum of 3% fibre was added. Impact resistance was also excellent after the addition of sisal fibre. Thus, coconut shell concrete with sisal fibre is considered as a suitable and eco-friendly construction material alternative for the construction industry.