STUDY ON BI-HIERARCHICALLY POROUS BIOCHAR FOAMED MORTAR FOR ACCELERATED CARBONATION

Abstract

Carbon sequestration in cementitious composites has long gained the interest of researchers due to its potential in reducing high CO2 emissions associated with cement production. The effect of carbon capture and sequestration can possibly be enhanced with the combined application of different methods or materials, such as in foamed concrete and through the use of biochar. Both biochar and foamed concrete have each proven to exhibit characteristics which aids in increased carbon capture capacity in past research studies, but the incorporation of both has not been extensively researched on. This research explores the combined use of foaming agent and pre-soaked biochar in cement mortar, which results in a double-layered hybrid foamed mortar comprising different levels of porosity, in improving CO2 absorption and maintaining reasonable compressive strength of the hybrid foamed mortar. The efficacy of Accelerated Carbonation Curing on CO2 absorption and compressive strength were also investigated. Effects of the combined use of foaming agent, biochar and ACC were evaluated through thermogravimetric analysis and compressive strength test. Findings suggested that the combined application of foaming agent and biochar in Type H samples increased CO2 uptake by 0.03-0.61%, while ACC contributes to an improved CO2 uptake of 0.51-1.13% compared to foam control. 28-day compressive strength test results of 11.8-16.4 MPa were obtained from the different Type H hybrid foamed mortar samples.