Utilization of waste clay bricks as coarse and fine aggregates for the preparation of lightweight aggregate concrete

The amount of waste clay bricks has been increasing as the demolition of old buildings in China, which has caused the serious environmental problem. Utilizing waste clay bricks as lightweight aggregates for preparing concrete is a new idea to consume them and save natural resources. Based on this concept, an experimental study was carried out to evaluate the feasibility of preparing lightweight aggregate concrete with waste clay bricks by testing the properties of prepared lightweight aggregate concrete. The results indicate that the dry densities of all mixtures are about 1700 kg/m3∼1850 kg/m3, meeting the standard requirement for lightweight aggregate concrete (≤1950 kg/m3), the 28-day compressive strength could reach up to 40 MPa, and corresponding static elasticity modulus is about 26 GPa. Moreover, both freeze-thaw resistance and carbonation resistance of all mixtures could satisfy the service requirements of Chinese standard (JGJ 51), and the chloride migration coefficient varies from 5.0 × 10−12 m2/s and 19.0 × 10−12 m2/s, corresponding with chloride penetration resistance of concrete from high to low. It has been proved that consuming waste clay bricks by preparing lightweight aggregate concrete with waste clay bricks as coarse and fine aggregates is a promising way and has application potentials.