Impact of rice husk ash (RHA) and nylon fiber on the bearing capacity of organic soil

Abstract

In the south-west part of Bangladesh, the regular systems of foundation are not suitable for the massive structure because an organic soil layer exists at a distance of 3–6 m from the ground surface. The existence of organic soil layer causes excessive settlement due to its high compressibility and low shear strength. To solve this matter, soil improvement is needed indispensably because it drops the construction expense and decreases the risk of further damage to the structures. Soil stabilization is an important method in the field of construction. The techniques of stabilization are used to enhance the strength of expansive or poor organic soil. In Bangladesh, huge amounts of industrial wastes are being produced every year due to fast urbanization and industrialization. Disposal of these waste materials is important as these are creating harmful effects on the environment. Rice husk ash (RHA) and nylon fibers are enormously available as industrial waste are dangerous if not disposed technically. Utilization of these industrial waste in ground improvement is likely to offer an admissible solution. This research represents the investigational results acquired from tests performed on organic soil stabilized with RHA and strengthened with randomly distributed nylon fibers. To investigate the impact of RHA and nylon fiber on strength properties of organic soil, standard proctor compaction, unconfined compressive strength (UCS), unsoaked and soaked CBR tests were conducted first on the soil samples partially replaced by RHA with dose 0%, 5%, 10%, 15%, 20% and then soil plus optimum percent of RHA and different content of nylon fiber (0.3%, 0.5%, 0.7%, 1%, 1.2%). The experimented results disclose that inclusion of different dosages of RHA and nylon fiber in organic soil leads to increase in the optimum moisture content and decrease in maximum dry density. The experimental results also express that the suggested technique is very effectual to improve the strength properties of poor organic soil in words of UCS, unsoaked and soaked CBR values. The result of this research work can be used as a guideline for soil improvement and can be used in the field of civil engineering.