Long-term Durability of Ordinary Portland Cement and Polypropylene Fiber Stabilized Clay

Soft soil stabilization frequently uses cement, lime, fly ash, etc., but very limited studies are available on its long-term durability. The present study deals with the long-term durability of commercially available EPK clay stabilized with ordinary Portland cement and polypropylene fiber. Experimental investigations were conducted to determine the percentage loss of soil during wetting–drying cycle, which is used as a durability indicator of cement and cement–fiber stabilized soil. Stabilized soil samples were subjected to harsh environmental conditions in a laboratory setup, and their deterioration was observed in each wetting–drying cycle. In the real world, stabilized soil encounters seasonal cycles of monsoon and summer in long run of its service life which is simulated as rapid wetting–drying cycle in laboratory setup. Samples were stabilized using a different percentage of cement, and a mix of cement–fiber and subjected to 12 cycles of wetting–drying to determine the percentage loss of soil as per ASTM standard. Finally, based on the percentage loss of soil for those samples which survived up to 12 cycles, the optimum content of stabilizing agent was determined. The results indicated that only the EPK clay stabilized with 5% and 10% cement in combination with 0.5% fiber survived up to 12 cycles but, only 10% cement mixed with 0.5% fiber was durable against wetting–drying cycle. For all the combination of 10% cement mixed with 0.5% fiber stabilized soil samples, after durability test the soil loss was less than 7%, which satisfy the Portland cement association’s durability specification.