Preliminary study of natural fibers with various treatment processes on properties of fiber-reinforced cement

Natural fiber has remarkable engineering properties, especially tensile strength. It can be used as a fiber reinforcement in cement composites with some environmentally friendly with economic advantages. Recycling of natural wastes could reduce PM 2.5 pollution during the burning season. However, those natural fibers require any pre-treatment processes to achieve more bonding ability with the cement matrix. The main aim of this study is to investigate the effects of various pre-treatment processes on the properties of fiber-reinforced cement. This test used rice straw and hemp fibers to represent the natural fibers. The results show that even the presence of natural fiber causes density and mechanical strength reductions, the elasticity through the deflection test is evidently increased up to 40.5%. All tested pre-treatment processes, i.e., using NaOH, HCl, and boiled in water, provided quite similar results in density and mechanical properties. The usage of NaOH seems to achieve good properties with reasonable price and simple preparation method. Moreover, applying less NaOH concentration or alternative non-chemical method (i.e., boiled water) could provide acceptable results with much less environmental impacts and costs.