Properties of concrete containing crumb rubber as partial replacement of fine Aggregate—A review

The rapid expansion of the global population and industrialization has resulted in more individuals relying on public and private transportation. Consequently, the rise in personal and commercial vehicle use has significantly contributed to the growing accumulation of scrap tires. Landfilling of waste tires in open mounds causes issues such as the spread of mosquito-borne diseases and landscape degradation. On the other hand, open burning of the tires is difficult as the subsequent fire extinguishing consumes many resources. Furthermore, there are concerns regarding fire safety and releasing harmful toxic gases into the air. Besides, the tire waste construction industry uses a lot of natural resources, such as sand, which are depleting. To avoid the depletion or scarcity of these natural resources, it is necessary to use alternative materials instead of sand. Indeed, methods to reuse or recycle tire waste must be devised. Research has started to explore the potential of using tire waste in the crumb rubber form, which is a waste product derived from the recycling of tires, as a partial substitute for fine aggregate in concrete. This review study aims to find the effect of crumb rubber (CR) in normal concrete as a partial replacement for sand. The study's objective is to provide a baseline for the effect of CR on normal concrete to provide a pathway for future studies working on rubber concrete to mitigate the limitations of the use of CR in concrete. A systematic meta-analysis is performed on the experimental facts from different studies to develop a model for optimizing the use of CR in concrete. The regression model adopted showed a good variation with the input data. The study finds that adding CR to concrete leads to a loss in its mechanical properties when crumb rubber is used. Despite the decrease in strength, rubberized concrete demonstrates enhanced durability characteristics, such as greater resistance to acid attack and chloride ion penetration, making it well-suited for environments with high chlorine exposure. This article provides an overview of the use of crumb rubber as an alternative substitute for fine aggregate in concrete and reviews the normal concrete's properties based on the research findings thus far.