Effect of Different Hydrophobic Treatments on Properties of Recycled Aggregate Concrete

The rapid infrastructure development in India has given rise to problems regarding management of construction and demolition waste. On the other hand, the negative impact of mining for natural resources has raised serious concerns about the environment. The government of India recognising the need of alternative aggregates for concrete permitted the utilisation of recycled and unconventional aggregates in the production of concrete. Previous studies regarding recycled aggregate concrete have mentioned the detrimental effect of recycled aggregates on concrete durability. The current study was designed to investigate the influence of three different types of hydrophobic treatments on mechanical and durability properties of recycled aggregate concrete. The concrete mix was designed to replace natural coarse aggregate by 10, 20 and 30% of coarse recycled aggregate. The recycled aggregate concrete mixes were subjected to (a) mixing-based treatment (b) aggregate-based treatment (c) surface-based treatment method. It was observed that mixing- and surface-based treatments improved the mechanical (compressive and flexural strength) and durability (acid attack, sulphate attack, chloride attack and DIN permeability) performance of concrete. For aggregate-based treatment, high-quality control was required failing which the durability of concrete was compromised.