New M.E.Thesis Submitted from Civil

Effect of Polypropylene on the Strength and Durability of Bagasse Ash Cement Stabilized Clay Soil by Tarun Sharma

Abstract

Soil is the foundation material which supports loads from the overlying structure. Many times, soil beneath the structure has weak geotechnical properties, which affects the stability of soil and hence failure of the structure occurs in the form of settlement and cracks etc. Construction of the embankments on the weak and thin foundation soils often poses problems for designers and contractors. Failure due to inadequacy of properties of soft soil, due to swelling and shrinkage of soft soils and due to differential settlement of buildings are some of the failures associated with construction of structures on soft soils. So it is imperative to take out the weak soil and replace it with decent additive or improvising the properties of soft soil by soil reinforcement or soil stabilization or combination of both. Researchers are always in chase for finding innovative techniques for ground improvement using sustainable and locally accessible materials.   

At present, the agricultural and industrial wastes are the major threats across the globe for the environment and humanity due to its disposal problem. Consequently, agricultural waste creates environmental pollution which disturbs the ecosystem. Due to this, engineers have to take challenge for safe disposal of industrial and agricultural wastes. This investigation undertakes use of agricultural waste (i.e. Sugarcane Bagasse Ash) with binding agent (i.e. Ordinary Portland Cement) in stabilizing the clayey soil and reinforcing it with industrial waste (i.e. Polypropylene fibers). Different endeavours have been made to enhance the strength parameters of soil utilising chemical additives as a part of mix with lime and cement, yet researchers need to concentrate more on effective usage of less expensive and locally accessible materials.  

Under this investigation, several unconfined compression tests were conducted in different stages on clayey soil with replacement of soil by SCBA (3%, 6%, 9% and 12%) only, by bagasse ash-cement mix and by bagasse ash-cement mix reinforced with PP-fibers. The unconfined compression tests were performed after 7, 14 and 28 days of curing periods. The outcomes show that the recommended technique is exceptionally effective to enhance the strength parameters of clayey soil as far as unconfined compressive strength is concerned and the durability of soil was also improved. It is found that the friction between the soil particles and fibers at their interface and bond strength seem to be controlling the benefit of reinforcement. For best utilization, the optimum percentage of SCBA, OPC and PP-fibers is 6% sugarcane bagasse ash, 6% ordinary Portland cement and 0.75% polypropylene fibers. Finally, it may be concluded that stabilisation of clayey soil with PP-fibers reinforcement is an effective method.