Laboratory Tests on Permeability of TDA-Weathered Rock Material Mixtures

As a kind of highly permeable and lightweight material, the tire derived aggregates (TDA) has been widely used in different aspects of geotechnical engineering such as retaining walls, abutments and embankments. Based on human health and environmental matters, the use of recycled TDA is gaining attention. The purpose of this study is to explore the permeability of TDA-weathered rock material mixtures. The TDA-weathered rock material mixtures were prepared with TDA in percentages of 20% and 40% by weight to evaluate its effects on the permeability. After TDA-weathered rock material mixtures were compacted, the compaction cylinder with TDA-weathered rock material mixtures was fixed in the developed variable-head permeameter. Results indicate that the permeability of mixtures increases obviously with the increment of water content when TDA percentage is 40%, but changes a little with the increment of water content when the TDA percentage is 20%. The permeability coefficient is higher when TDA percentage is 40%. The results are helpful to select the optimum mix proportions of TDA-weathered rock material mixtures.