Improvement of clayed soil using cement and polypropylene fi̇ber

Soil stabilization is the improvement of the soil's week engineering properties by lots of different methods. In this study, surface soil stabilization with cement and polypropylene fiber is discussed. The aim of this study is to examine the effect of cement and polypropylene fiber on engineering properties of the clayed soil. In this study, first of all, sieve analysis test, hydrometer test, specific gravity test and Atterberg limit test were performed to the soil, taken from Bursa Uludağ University campus, to classify the soil according to Unified Soil Classification System, which is classified as low plasticity clay soil. Then, 5%, 10% cement and 0,5%, 1,0%, 1,5% polypropylene fiber are added to this natural soil to prepare test specimens. These test specimens' optimum water contents and maximum dry unit weights are obtained by Proctor compaction tests. After that, the samples are prepared according to their optimum water contents and unconfined compression tests, California bearing ratio (CBR) tests and swelling tests are done on these samples. The samples that prepared for unconfined compression tests are kept in desiccator for 1, 7 and 28 days and then they are tested. The results of the experiments show that additives added to the natural clay soil improves the soil's engineering properties. However, polypropylene fiber added to the soil reduces the unconfined compressive strength of the soil a little bit due to the coagulation of the fiber inside the soil. In addition, curing time increases the unconfined compressive strength of the cemented samples as expected.