Abstract

This study aimed at producing high-strength lightweight concrete using sustainable agricultural materials. Concrete units were fabricated by partially substituting fine aggregates with rice husk (RH) and incorporating cassava starch (CS) as an organic admixture. Eight concrete units were manufactured, and their mechanical properties assessed through procedures approved by ASTM standards. The results revealed that as the RH percentage increased from 0 to 15%, there was a decrease in the slump of the fresh concrete, dropping from 35.3 to 14.7 mm. The findings revealed that the concrete density decreased consistently, with the increment in the rice husk quantity (0-15%) integrated into the concrete. Similarly, it was observed that the addition of cassava starch led to an increase in both concrete density and compressive strength, irrespective of the content RH incorporated into the concrete. The compressive strength of the concrete, produced with 0, 5, 10, and 15% RH without the inclusion of CS, measured 19.7, 19.1, 16.8, and 15.2 MPa, respectively. In contrast, the counterparts (0, 5, 10, and 15% RH) manufactured with the addition of 1% CS exhibited compressive strengths of 21.4, 20.3, 18.1, and 16.5 MPa, respectively after 28 days of curing. The results demonstrated that addition of low RH volume and 1% CS can produce concrete with compressive strength appreciable for the construction of farm buildings. These results provide positive indications that agricultural residues can indeed be utilized to produce sustainable concrete for applications in agricultural production.