Laboratory investigation of road bed improvement using rubber fibers, zeolite, cement and lime

Due to the great importance of creating roads in coastal areas in the economy and connecting highways between eastern and western cities, these soils need to be improved. One of the conventional methods to improve the mechanical properties of soils is the use of stabilizers such as lime and cement. Another method that has been used in recent years is the use of synthetic or natural fibers to strengthen soils. Considering the environmental problems created by conventional stabilizers (cement/lime) and also their economic costs, the use of pozzolan, which has a lower cost, can be a suitable solution as a substitute for these materials. Considering the importance of the topic in the field of improvement, in this research, the effect of two types of pozzolanic additives (zeolite) and rubber fibers on the compressive strength of sand samples stabilized with cement and lime has been investigated using a uniaxial test. The results of the tests show that cement has more effective effects than lime in increasing the compressive strength of the soil. The ratio of compressive strength of cement samples to lime samples is about 650%. Also, lime-stabilized fiber-reinforced samples and cement-stabilized fiber-reinforced samples have an increase in compressive strength by about 50 and 110%, respectively, compared to the case of cement or lime-stabilized samples without fibers. Replacing cement and lime with zeolite does not show a change in compressive strength, which indicates a more appropriate behavior from an economic and environmental point of view.