Optimization of mechanical properties in foamcrete reinforced with raw oil palm empty fruit bunch (EFB) fiber

Abstract

As Malaysia currently heading to biotechnology hub, it is expected that billions tons of palm oil by-products will be produced annually and normally been treated as waste disposal. A large amount of agricultural waste produced in the processing of palm oil is one of the main contributors to the environmental problem. This paper presents an experimental study on the development of the lightweight foamcrete with the inclusion of raw oil palm empty fruit bunch (EFB) fiber. EFB fiber has potential to be developed as alternative fibers in fiber reinforcing concrete. The study was focused on 4 mechanical property parameters which were axial compressive strength, flexural strength, splitting tensile strength and performance index. Three densities of lightweight foamcrete of 800, 1100 and 1400 kg/m3 were cast and tested. The ratio of cement, sand and water used in this study was 1:1.5:0.45. EFB fibers were used as additives at 0.15%, 0.30%, 0.45%, 0.60% and 0.75% by volume of the total mix. The results obtained from the experiments had indicated that the flexural strength of foamcrete reinforced with raw oil palm EFB fiber at different percentages for 800, 1100 and 1400kg/m3 densities correspondingly. For all densities, 0.45% EFB fiber reinforced foamcrete contributed to highest flexural strength. Same pattern can be observed on the compressive and splitting tensile strengths. EFB fiber aid in precluding the promulgation of cracks in the plastic state when load was applied. When the lightweight foamed concrete expands under axial compression and splitting tensile loads which will lead to cracking, the crack has a restricted distance over which it can spread before reaching the EFB fiber, preventing the crack from growing further. EFB fibers which were randomly dispersed in the mix provide three dimension reinforcement compared to the traditional rebar which provides two dimension reinforcement.