Long-Term Durability of Ordinary Portland Cement and Polypropylene Fibre Stabilized Kaolin Soil Using Wetting–Drying and Freezing–Thawing Test

Soft soil stabilization frequently uses cement, lime, fly ash, etc., but very limited studies were conducted on the long-term durability of stabilized soil. The present study deals with the long-term durability of commercially available kaolin soil stabilized with ordinary Portland cement (OPC) and polypropylene fibre using a much more realistic approach, where the effect of weathering action can be observed in each cycle. Laboratory investigations were conducted to find the percentage loss of stabilized soil during wetting–drying and freezing–thawing tests, which are used as a durability indicator of cement and cement–fibre-stabilized soil. The stabilized soil encounters seasonal cycles of monsoon and summer in long run of its service life, which is simulated in rapid harsh weathering cycles in a laboratory setup. Kaolin soil samples were stabilized using different percentages of cement and mix of cement–fibre combination and were subjected to 12 cycles of wetting–drying and freezing–thawing cycles separately to determine the percentage loss of soil in accordance with the ASTM standards. Results of wetting–drying tests indicate that kaolin soil stabilized with cement and fibre combination survived up to 12 cycles, but only 10% cement + 0.5% fibre was durable against wetting–drying test based on percentage loss. Results of freezing–thawing tests indicate that only the kaolin soil stabilized with 10% cement, 5% cement + 0.5% fibre, and 10% cement + 0.5% fibre survived up to 12 cycles and are durable against freezing–thawing test based on percentage loss which satisfies the Portland Cement Association’s durability specification.