Investigation of recycled tire chips for use in GDOT concrete used to construct barrier walls and other applications

This study investigates the use of recycled tire chips as a replacement for natural aggregates in concrete mixtures to improve the impact resistance of concrete barrier walls. The first phase of the project was used to replace large quantities of both coarse and fine aggregates to determine the maximum replacement proportions that could be achieved while maintaining adequate concrete strengths per GDOT standards. The second phase of the project was limited to replacing 20% of the volume of coarse aggregates with recycled tire chips and employed surface treatments to the rubber particles for better adhesion to the cement matrix. A full suite of tests on fresh and hardened concrete properties was performed and adequate strengths were achieved for a replacement up to 20% with recycled tire chips. The rubberized concrete mixtures showed an improved toughness and the ability to resist impact loads when compared to control mixtures.