Improving the properties of recycled aggregate pervious pavement blocks through bio-mineralization

Pervious concrete (PC) comprised of cement, water, coarse aggregates are widely used nowadays for sustainable and low impact pavement. The primary purpose of this study is to investigate the performance enhancement of pervious concrete blocks (PCB) containing recycled coarse aggregates (RCA) through microbially induced calcium carbonate precipitation (MICP). Two types of bacterial enhancement methods were adopted, which are PCB with pre-soaked RCA using bacteria solution and PCB with bacteria added mixing water. The properties of RCA, cement paste, and PCB were measured. The water absorption of RCA soaked in the bacteria and culture medium for 21 days was reduced by 10.41%. Meanwhile, the porosity of PCB decreased by 15.70%, and compressive strength increased up to 28.48% when incorporating pre-soaked RCA. There was an increase of 57.23% in compressive strength for hardened cement paste when bacteria were added in the mixing water. The compressive strength of PCB increased by 35.48% when compared with PCB with normal mixing water. Both enhancement methods show promising results and realize the purpose of enhancing the properties of PCB containing RCA.