Enhancing the performance of pervious geopolymer concrete incorporated coated biomass aggregate: A mathematical modeling approach

Researchers have investigated diverse approaches to developing sustainable construction materials, with particular attention to enhancing the mechanical performance and water permeability of pervious geopolymer concrete (PGC). PGC has been introduced as an alternative to conventional Portland cement (OPC) and natural aggregates (NA), offering both structural improvements and environmental benefits. In this study, biomass aggregate (BA) was produced from incinerated palm oil biomass, while coated biomass aggregate (CBA) was synthesized by combining BA with alkaline liquid (AL) and fly ash (FA), followed by curing at 80 °C for 24 h. Experimental results demonstrated that PGC incorporating CBA achieved a maximum compressive strength of 13.7 MPa, representing a 121 % increase compared with the OPC–NA reference mix (6.2 MPa) and a 65 % improvement over PGC containing BA (8.3 MPa). Importantly, this strength enhancement was obtained without reducing permeability. The CBA–PGC mixtures exhibited permeability values up to 2.1 cm/s, closely comparable to OPC–NA (2.15 cm/s) and higher than the 1.81–1.98 cm/s range recorded for BA–PGC. The optimum mixture was achieved with a FA:CBA ratio of 1:7, NaOH concentration of 10 M, an AL/FA ratio of 0.5, and curing at 80 °C for 24 h. These findings indicate that incorporating CBA into PGC significantly improves compressive strength while maintaining adequate water permeability, thereby highlighting its potential as a sustainable aggregate alternative. Furthermore, multiple linear regression models were developed to predict compressive strength (fc’) and permeability (k) across different pervious concrete mixes. The models achieved R²values above 0.9, confirming their predictive accuracy and reliability. Overall, this study demonstrates the viability of utilizing industrial by-products such as BA and CBA to produce high-performance, eco-efficient PGC, contributing to the advancement of sustainable construction materials.