Improvement in properties of concrete with modified RCA by microbial induced carbonate precipitation

The mechanical and durability properties of recycled aggregate concrete (RAC) are generally inferior to conventional due the old mortar attached surface original aggregate, which induces more complicated interfacial transition zones (ITZs) in RAC. microbial induced carbonate precipitation (MICP) modification is a novel environmentally-friendly method improve ITZs In this study, physical coarse (RCA) before after MICP were tested; then, effects on with RCA modified investigated. SEM observation microhardness test conducted reveal micro mechanism improvement modification. results show that exhibits lower water absorption apparent density; specimens higher compressive strength, steel corrosion resistance, less corrosion-induced cracks, can be explained by enhanced ITZ between new mortar.