Evaluation and Application of Peanut Biochar in Cement Mortar Under Water and Carbonation Curing

Abstract

Utilization of biochar derived from daily waste to replace part of cement is an environmental method to make sustainable concrete. This study investigates the possibility of using waste biomass to prepare biochar, which can be used as an admixture in cementitious composites. Preparation and investigation of some key physical properties, including phenolphthalein test, strength and shrinkage, of cement mortar with peanut husk biochar are explored. 1% and 3 % weight of cement were replaced by biochar in cement mortar and prepared biochar-mortar was subject to water curing and carbonation curing and its effect on the mentioned properties were studied. Findings showed that using peanut husk biochar to replace 1% and 3% of cement improve strength (28-day age) of mortar slightly compared to control under both curing, attributed to densification effect of biochar in mortar matrix. Addition of biochar also increased drying and carbonation shrinkage with the increase in biochar dosage. Water absorptivity test confirmed that blend of biochar improved secondary water absorptivity because of more pores in biochar. Overall, this research suggests that peanut husk biochar can be utilized as a filler admixture in cementitious composites, which also provide a means to sequester carbon in mortar and reduce pollution.