Experimental Investigation of Compressibility of Cohesive Soil Mixed with Waste Tire Chips

A large number of scrap tires become out of use each year and enter environment. Dumping of waste tires in engineered designed landfills may not economically be justified. Therefore finding applications for such materials is environmentally sound. On the other hand, some soft clays are found in practice, which make problems. Although, geotechnical engineering has dealt with such problems by the use of appropriate foundations such as piles, caissons, etc., the soil improvement may also be considered in some cases. Such consideration becomes more valuable when environment issues are present. This paper presents the results of a series of consolidation tests performed on a cohesive soil mixed with various percentages of waste tire chips. Similar mixtures have also been prepared using a sand of the same size distribution as tire chips. This helps to distinguish the effectiveness of using tire chips for fine soil improvement. The volume of sand and tire chips in a certain mixture was kept the same for comparison. The results show that adding sand to the clay can improve the compressibility as expected. The addition of tire chips to the clay can also reduce the compressibility. Having the same volumes of sand and tire chips in each mixture, it will be shown that the compressibility of tire chip-clay mixtures is comparable to that of sand-clay mixture containing the same sand volume does. This is encouraging since the use of waste tires in engineering projects can reduce environmental impact.