Role of Fly Ash on Strength Properties of Rejuvenated Soil Cement for Pavement Materials

Abstract

Stabilization with cement is the most commonly used technique for the improvement of soil physical, mechanical, and engineering properties. This research reported on the properties of the rejuvenation for recycled soil cement with incorporation of fly ash (FA). The study showed that the specific gravity of Rejuvenated Soil Cement (RSC) decreased with increasing FA. The free swell ratio and linear shrinkage of RSC were significantly decreased with the increase in FA. The maximum dry unit weight of RSC increased with increasing FA up to the optimum FA content of 20 – 25 %. The optimum water content in compaction was relatively constant with the increase in FA. Particularly, the strength improvement in active zone of FA-RSC was influenced by several factors viz., compaction, packing, rehydration, and pozzolanic reaction. As a result, the unconfined compressive strength (UCS) of RSC increased with increase in FA and curing time. This research clearly showed that the rejuvenation of soil-cement with FA as additive was successful. It was also shown that the normalized UCSs of RSC at various curing times could be used to predict the UCSs at 7 and 28 days.

Keywords

• rejuvenated soil cement
• pozzolanic reaction
• rehydration effect
• unconfined compressive strength
• secant modulus of elasticity