Utilization of sandstone waste in cement mortar for sustainable production of building materials through biomineralization

Sandstone waste generated during stone cutting and processing is a major environmental problem. In this study, different ratios of sandstone powder was utilized as a cement replacement and the mortar specimens were treated with bacteria to enhance the durability properties. With replacement ratio of sandstone powder (10% to 40%), strength loss was observed in all the sandstone-modified mortars. Due to bacterial treatment in CSB10, CSB20, CSB30 and CSB40 specimens, compressive strength was increased by 11%, 12.8%, 17% and 6%, respectively compared to their respective controls. Water absorption rate was significantly reduced and lower sorptivity coefficient was recorded in bacterial treated specimens. In bacterial treated CSB30 specimens, compressive strength recovery (17%) and reduced sorptivity coefficient (0.002) were observed. Present study results suggest that microbial treatment of sandstone modified mortar with a 30% replacement ratio of cement is a possible solution for utilizing stone waste in the construction industry.

Automated summary

This study enhanced the compressive strength and durability properties of sandstone-modified mortar through bacterial treatment. Using sandstone powder as a replacement for cement, the bacterially treated mortar specimens showed lower water absorption rate and higher compressive strength.