Axial compressive behavior of concrete incorporating crumb rubber pretreated with waste quarry dust

Rubber decomposition is extremely slow and time-consuming. Thus, the disposal of waste tires causes environmental issues and is very dangerous for public health. One way to reduce this environmental burden is adding waste rubber to develop green concrete. Using crumb rubber as aggregate in concrete reduces its mechanical performance. In order to enhance the mechanical properties, the use of waste quarry dust (WQD) - a waste material - for pretreating crumb rubber has been investigated in this study. The research aims to evaluate the mechanical behavior of concrete incorporating rubber particles pretreated with WQD. Nine different mixes were made in which one mix contained no replacement of sand, whereas four mixes were made by substituting (5%, 10%, 15%, and 20%) of sand by volume with non-treated rubber; the remaining four contained treated rubber with WQD. The compressive stress-strain curve was examined completely, and the compressive strength, modulus of elasticity, ductility, energy absorption capacities, toughness index, and failure mode of concrete specimens, were evaluated. Also, the tensile strength of all samples was investigated. The 20% replacement of treated rubber with sand increased the compressive strength, modulus of elasticity, and tensile strength up to 100%, 86%, and 85%, respectively, compared with the same replacement percentage of non-treated rubber. The 20% substitution of sand with non-treated rubber showed 23% and 49% increased value of ductility and toughness index, respectively, compared with a similar percentage of treated rubber. It was observed that treated rubber exhibited slightly less improvement in post-peak behavior than untreated rubber. The outcome of this rubber treatment approach provides an overview of the effect of rubber treatment on the compressive stress-strain behavior of concrete.

Automated summary

Rubber decomposition is slow and harmful to the environment and public health. Adding waste rubber to green concrete can alleviate this environmental issue. In this study, the use of waste quarry dust (WQD) for pretreating crumb rubber was investigated to enhance the mechanical properties of concrete. The results showed that treated rubber exhibited better performance than untreated rubber in certain aspects.