This study aimed to evaluate the effect of coconut husk and Expanded Polystyrene (EPS) composition on the mechanical and acoustic properties of lightweight concrete. The research was conducted experimentally using a two-way factorial design with coconut husk variations of 0%, 0.5%, 1%, 1.5%, and 2% of cement weight and EPS variations of 0%, 10%, 20%, and 30% of coarse aggregate volume. A total of 20 mix variations (5 coir levels × 4 EPS levels) were prepared with three replications for each test, resulting in 120 specimens. Compressive strength was tested at 7 days following ASTM C39, while sound absorption was measured at frequencies of 100–2000 Hz based on ISO 10534-2. The results showed that the addition of coconut husk up to 1% improved compressive strength through fibre reinforcement, whereas increasing EPS content enhanced sound absorption due to higher porosity but reduced mechanical strength. Statistical analysis using ANOVA (R² = 0.94, p < 0.05) and desirability optimisation identified the optimal composition at 1% coconut husk and 10% EPS. The developed lightweight concrete is suitable for non-structural building components requiring improved acoustic performance and reduced weight.
Copyrights © 2026