Application of waste tire rubber and recycled aggregates in concrete products: A new compression casting approach

Abstract The inferior performance of eco-friendly concrete owing to the addition of waste materials is a big hurdle in its practical adaptation. This study focuses on developing eco-friendly and green concrete, having performance similar to normal aggregate concrete (NAC). For this purpose, two waste products, including recycled aggregates (RA) and waste tire chipped rubber (CR), were used during the study. Furthermore, green concrete was also manufactured using RA treated through techniques such as lime immersion with carbonation and acetic acid immersion with mechanical rubbing. To achieve the strength of green concrete similar to NAC, an innovative concrete casting approach was followed. Green concrete specimens were cast and then compressed in the fresh state using specially designed molds. Results show that the compressive strength of recycled aggregate concrete (RAC) incorporating 20% CR in replacement of coarse aggregates is noticed 49% lower than NAC. However, the compressive strength and elastic modulus of compressed RAC and treated RAC incorporating 10-20% of CR in replacement of coarse aggregates are quite close to traditional concrete specimens without CR. No such method is available in the current literature through which green concrete incorporating RA and CR can achieve properties similar to NAC. Furthermore, the cost comparison and cement strength contribution index calculated in this study also show the industrial application potential of the new casting approach. Therefore, the developed concrete casting approach promotes the efficient utilization of RA and CR in the production of precast concrete members resulting in eco-friendly and sustainable construction.