Evaluation of the Performance of Sack Polypropylene Recycled Fibers on the Strength Parameters of Babolsar Sand with Different Percentages of Cement

To implement asphalt roads in an area, in many cases, especially in poor and swampy areas, there is a need for improvement. In recent years, the use of reinforced soil is common for the design of roads, foundations and retaining walls. On the other hand, the solid waste management, in terms of large volume and longtime decomposition of wastes such as sack polypropylene fibers, in addition to its effective role in the economic cycle is as one of the important indicators of development at the macro level in developing countries. Therefore, reinforcing of soil with the use of waste materials has a particular importance. In this research, by performing a laboratory experiment, the effect of adding various percentages of sack polypropylene fibers on the behavior and values of strength parameters of non-cemented and cemented sand (with three weight ratios of 3, 5 and 7% and 7-day treatment time) were investigated. The results show that the presence of these fibers has a significant effect on the behavior of non-cemented and cemented sand. Adding these fibers improves the strength parameters (φ and C), increase the maximum strength, failure strain and residual strength of soil. The effect of these fibers on the all studied parameters in non-cemented soil is higher than that of cemented soil. Also, their effect becomes less by increasing the percentage of cement in cemented soil. According to the research, these materials can be used in the road beds, which has environmental benefits, in addition to economic benefits