Experimental investigation on engineering properties of lightweight foamed concrete (LFC) with coconut fiber addition

In the last few years, there is emerging attention in using Lightweight Foamed Concrete (LFC) as a lightweight non-structural and semi-structural element in buildings to take advantage of its excellent insulation properties. Though, LFC has been noticed to have some disadvantages: considerable brittleness; results in low compressive and flexural strength, poor fracture toughness, poor resistance to crack propagation and low impact strength. Coconut fibre obtained from coconut husk, belonging to the family of palm fibres, is agricultural waste products obtained in the processing of coconut oil. In Malaysia, they are available in large quantities. Coconut fibre is extracted from the outer shell of a coconut. There are many general advantages of coconut fibres e.g. they are moth-proof, resistant to fungi and rot, provide excellent insulation against temperature and sound, not easily combustible, flame-retardant, unaffected by moisture and dampness, tough and durable, resilient, springs back to shape even after constant use, totally static free and easy to clean. Hence this study is intended to look into the potential of coconut fiber in enhancing the engineering properties of LFC. There are 5 engineering properties will be focused in this study which are flexural strength, splitting tensile strength, compressive strength, Poisson’s ratio and Poisson’s ratio toughness. Three densities of LFC of 800 kg/m3, 1100 kg/m3 and 1400 kg/m3 were cast and tested. The ratio of cement, sand and water used in this study was 1:1.5:0.49. Coconut fibers were used as additives at 0.12%, 0.24%, 0.36%, 0.48% and 0.60% by volume of the total mix. Test results indicated that the engineering properties of LFC strengthen with coconut fiber had increased soundly. Coconut fiber inclusion changes the post-peak response at the load-deflection curves for the samples, which modifies the failure mode and enhance the flexural strength, compressive strength and splitting tensile strength