The Rubber-Soil is a new kind of construction material which is made from recycled wire-free rubber chips derived from scrap rubber tires and bonded together by rubberised cementitious material. It is proposed to be used in many civil engineering applications such as a backfill material in retaining wall and a sub-base material in pavement. This research aims at understanding the general behaviour of Rubber-Soil in both geotechnical and environmental aspects....[ Read more ]

The Rubber-Soil is a new kind of construction material which is made from recycled wire-free rubber chips derived from scrap rubber tires and bonded together by rubberised cementitious material. It is proposed to be used in many civil engineering applications such as a backfill material in retaining wall and a sub-base material in pavement. This research aims at understanding the general behaviour of Rubber-Soil in both geotechnical and environmental aspects.

Many conventional geotechnical testing, unconfined compression test, static and cyclic triaxial test, direct shear test, consolidation test, creep test and permeability test, were conducted on the Rubber-Soil to study its shear strength, compressibility and permeability properties. The experimental investigations have indicated that the material exhibits favourable qualities such as high strength and stiffness, lightweight, porous, good dynamic behaviour and creep resistance. It was also found that the material behaviour is similar to that of cemented soil especially for the shear strength behaviour. The material's resistance maybe contributed by both cementitious bonding and frictional resistance of its reconstituted state. The damage mechanics was found to be suitable to describe the shear strength behaviour also.

Apart from the understanding in geotechnical aspect, environmental investigation is also important to convince the implementation of the material. Toxicity Characteristics Leachate Procedure Test and Leaching Lysimeter Test were conducted to investigate the influences of environment by the material. The results showed that the material is non-toxic and is harmless to the environment and human life. Besides the leaching properties, the influences in shear strength properties when subjected to critical conditions such as acid rain attack were also studied by simulation. It was found that long term freezing induced greatest deterioration on the material, however, can be compensated by strengthening the design mix.