Enhanced Pozzolanic Activity of Crushed Brick Powder with Hydrated Lime: Concrete Durability Study

Abstract

This study investigated the potential of incorporating crushed brick powders (CBPs) and hydrated lime (HL) as additives in concrete production. Various tests were conducted on mortar, paste, and concrete samples to evaluate the performance of different blend types. The results reveal that among 3%, 6%, 9%, and 12% HL additive in the cement-CBP blend, 6% HL addition yields a significant increase in compressive strength of up to 16% compared to the control mortar. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) indicate improved hydration and reduced calcium hydroxide content in CBP-blended pastes, particularly in the blend with 6% HL. The concrete blend incorporating crushed bricks (C-CB) with 6% HL (C-CB-6HL) demonstrates superior early strength gain, surpassing the control blend by approximately 2.1% at 28 days and exhibiting the highest compressive strength at 90 days. It also shows enhanced moisture resistance, with a reduction in water absorption percentage of up to 10.6% compared to the control blend, reduced water permeability, improved resistance against chloride permeability, and better durability against acid attack compared to other blends. Overall, the C-CB-6HL blend shows the most promising durability characteristics, highlighting the potential for sustainable concrete production. Its outcomes have implications for shaping technical standards and promoting sustainable practices in the construction industry, aligning with environmental conservation goals.