CARBONATION AND RECYCLING OF HIGH-STRENGTH CONCRETE

Abstract

At present, concrete industry is concerned with the sustainability of the built environment. Durability of concrete plays an important role is achieving this. Among the various deterioration processes that affect the durability, concrete carbonation has become the focus, due to the increase in the carbon-dioxide (CO2) levels across the globe. Casting fresh cementitious materials against a hardened concrete substrate is a common practice in precast construction, leading to the formation of cold-joints or construction joints. These joints may have an important impact on concrete durability. Owing to the lack of proper curing and poor workmanship, the joints become the points of attack in aggressive environments. The accelerated carbonation of test specimens with the vertical interfaces formed between freshly cast cementitious mixtures and hardened concrete substrates was carried out. The effect of w/c ratio and the size of coarse aggregates on the microwave beneficiation method and carbon sequestration were also investigated.