Simplified Material Model for Concrete Containing High-Content of Tire-Derived Coarse Aggregate under Compression Loading

The flexible properties of the shredded rubber tires give rubberized concrete desirable properties such as lower relative density, and better dampening ability, higher toughness, and improved deformability resulting in an enhanced dynamic performance. Limited work has been done in modeling these effects. In this study, natural coarse aggregates in concrete mixes were replaced by volume by shredded tires up to 100% replacement ratios following 10% increments. Compression tests were conducted to investigate the effects shredded tires on the mechanical properties of concrete. As expected, the results showed a decrease in the compressive strength and the elastic modulus of the concrete as the replacement ratio increase. Due to compatibility, strain at peak values increased and the integrity of the concrete after failure was enhanced. Models describing the effects shredded tires have on the mechanical properties of the concrete were developed and validated against experimental data from various researchers.

Assessing the environmental impact of shredded tires as embankment fill material

This article deals with the assessment of the environmental impact of shredded scrap tires mixed with sand to build embankments. Pollution of water as well as consequences of fire ignition were considered. Percolation, lixiviation, and lysimeter tests were performed on the raw material as well as on residue resulting from the fire. The collected liquids were analysed considering 200 physicochemical parameters. Their toxicity on a small shellfish and a bacterium was assessed. Measurements were compared with existing regulations and recommendations. Fire propagation risk in the core of the embankment and on the surface was also investigated. Measurements confirmed the limited consequences on the environment except in the case of fire, where residue must be considered hazardous waste.