Synthesis of Coconut (<i>Cocos nucifera</i>) Husk Fiber-Silica Composite as Concrete Additive

Abstract

Concrete is extremely vulnerable to crack formation. However, repair and monitoring can be labor-intensive and costly. The investigation focused on the augmentation of natural fiber-silica composite-containing concrete’s mechanical properties. Raw coconut husk fiber (CHF) was used to mix with sodium metasilicate, and the synthesized coir-silica composite (CSC) was mixed in a cementitious matrix to test its self-healing properties. The synthesized composite (CSC) has a sheet-like morphology, whereas the silica has a rough surface morphology based on the SEM-EDX micrographs. The presence of silica improved the thermal stability of the raw coconut husk fiber (CHF). Results demonstrated that both pristine condition and healed samples had enhanced mechanical properties with the addition of the CSC material. Hence, the produced composite embedded in concrete surpassed control specimens in terms of healing capability for compressive and tensile strengths after damage. Finally, a synthesis method was developed to prepare a coconut husk fiber-silica composite, demonstrating a viable upcycling route for coconut husks waste utilization.