Impact of waste glass powder on mechanical properties and microstructure of rubber concrete

To reduce the pollution of waste glass powder (GP) and waste rubber (WR) on the environment, GP is added into rubber concrete as a mineral admixture. The mechanical properties of rubber concrete incorporating with 0-30% of GP are investigated. The microstructure of rubber concrete is determined through scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP), and the nanomechanical properties are determined by nanoindentation technique. The results demonstrate that the utilization of GP decreases the early strength and elastic modulus of rubber concrete, and more than 10% GP degrades seriously the microstructure. However, the addition of 10% GP enhances the compressive strength and elastic modulus at the later ages, and promotes the generation of calcium silicate hydrate (C-S-H) gel that compacts the microstructure of rubber concrete. The nanomechanical properties of the interfacial transition zone are also improved effectively due to the addition of 10% GP.