Development of high-performance self-compacting concrete using waste recycled concrete aggregates and rubber granules

In recent decades, self-compacting concrete has slowly gained popularity since its inception due to its unique ability to fill formworks with congested steel reinforcement and with little to no use of mechanical compaction required. Due to the environmental impacts associated with the natural aggregates in concrete production, a more sustainable approach in producing self-compacting concrete is to replace natural aggregates with that of recycled concrete aggregates from common construction waste and demolitions. This form of concrete provides a sustainable alternative in minimising the environmental damages associated with the extraction and depletion of natural resources. This experimental research aims to develop information about the fresh and hardened properties of different forms of self-compacting concrete by utilising recycled concrete aggregates in combination with recycled crumb rubber or lightweight scoria aggregates. The fresh properties were investigated in accordance with the guideline provided by the European federation national representing of concrete using the slump flow, T500, and J-ring tests. Hardened properties include 7 and 28 day compressive and tensile strengths, hardened density testing, and compressive stress-strain behaviour at 28 days. Optimal mix design of recycled concrete and crumb rubber aggregates self-compacting concrete are assessed to optimise fresh and hardened properties. The proposed SCC mixes are able to reduce amount of used cement to 40%. Aslo, as the percentage of recycled aggregate replacement increased, developed SCC mixes flowability and passing ability decreased.