Evaluation of the Mechanical Properties of Coconut Biomass Reinforced Concrete Composites for Sustainable Construction

The incorporation of coconut biomass into cementitious composites has received increasing attention due to its environmental and structural benefits. This study investigates the impact of coconut biomass dispersion in concrete at concentrations of 1%, 1.5%, and 2% (by weight), analyzing mechanical properties such as axial and diametral compressive strength, as well as the influence of this biomass on the carbonation process. The main results showed that the 1% biomass concentration promoted better homogeneity in the cementitious matrix, resulting in a 28% increase in compressive strength compared to the 2% biomass composites. Furthermore, it was observed that the presence of biomass delayed the progression of carbonation, maintaining the pH above critical levels for reinforcement protection, with values up to 9.5 at the end of the process. For the composite prepared with 3% (w/w), although the initial pH remained relatively high (11.5 to 12.0), the additional porosity caused by the excess biomass can accelerate carbonation, reducing the final pH to about 8.5 to 9.0, a value comparable to biomass-free concrete. The optimum biomass concentration, 2% (w/w), presented the best performance in terms of mitigating carbonation and maintaining pH.