Improvement of Tensile Properties of Cement-Stabilized Soil Using Natural Rubber Latex

Abstract

Unpaved cement-stabilized roads are commonly used for vehicular transportation in the rural areas of developed and developing countries. The high cement content of such roads, however, reduces the tensile fatigue life, especially at locations with a large strain level, resulting in the occurrence of sudden failure due to the initiation of cracks. In order to mitigate this current shortcoming, natural rubber latex (NRL) was studied in this research as an environment-friendly additive for cement stabilization works. The addition of NRL in a liquid state was found to be convenient for fieldwork implementation. The effect of influence factors was studied in this research, which included types of soil, NRL replacement ratio, water content, cement content and compaction energy on unconfined compressive strength (UCS), indirect tensile strength (ITS), and indirect tensile fatigue life (NF). Portland cement (Type I) contents were varied to 3%, 5%, and 7% by weight of dry soil, and NRL replacement ratios were varied to 10%, 15%, 20%, 25%, and 30% by weight of liquid admixture of water and NRL. The UCS, ITS, and NF values were found to increase when increasing the NRL replacement ratio, up to the highest value at the optimum NRL replacement ratio. The maximum ITS, which is directly related to UCS, was found at optimum liquid content (OLC). Although the cement-NRL-stabilized samples exhibited higher total deformation under a particular fatigue tensile stress, the plastic deformation was found to be significantly lower when compared with cement-stabilized samples at similar cement contents. This indicates that NRL replacement improves the capacity to withstand the developed plastic strain against fatigue. Furthermore, the CO2-e emission values for cement-NRL-stabilized soil were found to be lower than that of cement-stabilized soil at a similar ITS.