Effects of CO

The increasing impact on environment due to the mining of river beds for the use of natural river sand as fine aggregate in mortar/concrete demands for sustainable methods. Hence, in this present study to reduce the use of natural river sand in mortar/concrete, a sustainable alternative method was investigated. This method involves the use of Recycled Brick Powder (RBP) as an alternative to river sand in cement mortar. In this present study, CO2 sequestration method was employed on RBP and was used as a partial replacement to river sand in cement mortar. Recycled Brick Powder (RBP), which was obtained by crushing the construction demolition waste, was carbonated at various levels (0%, 10% and 20%) of CO2 concentration in an accelerated carbonation chamber. This CO2 sequestrated RBP was replaced at 0%, 25% and 50% by weight of that of natural river sand. Flow table test was conducted to determine the consistency of the cement mortar mixes. The compressive strength was determined at the ages of 1, 3, 7 and 28 days of curing. From the obtained results, it was observed that the increase of RBP percentage tends to reduce the consistency of cement mortar and the compressive strength. From the compressive strength test results, it was found that CO₂ sequestration had positive effect on both the consistency and compressive strength of cement mortar containing RBP. An increase in compressive strength of about 4% was observed with carbonated RBP. This research confirms that CO2 sequestered RBP can be used as a low-carbon eco-friendly sustainable fine aggregate that helps in carbon reduction and preservation of natural resources.