Effect of Basalt and Polypropylene Fibers on Unconfined Compressive Strength of Cement-Stabilized clay, an Experimental Approach

Document Type : Original Manuscript


1 Department of Civil Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran

2 Department of Civil Engineering, Gonbad Kavoos Branch, Islamic Azad University, Gonbad Kavoos, Iran


So far, many studies have been done on the performance of conventional chemical stabilizers such as cement, lime, fly ash or other chemical additives. However, very limited researches were conducted on the mechanical behavior of cement-stabilized soil with fiber inclusion. Fiber-reinforcement of a stabilized soil offers new opportunities to improve ductility and strength characteristics of weak soils. The main objective of this research is considering the effects of curing time, initial moisture content, polypropylene fiber (PPF) or basalt fiber (BF) with or without addition of cement on the Unconfined Compressive Strength (UCS) of the clay soil. Different ratios of PPF or BF and/or cement were added to the soil to identify their influences on the UCS. The study finds that adding cement, PPF or BF to soil causes a remarkable increase in the strength. The strength of the PPF-reinforced specimens was observed significantly more than that of BF-reinforced ones. The strength of specimens increases gradually as the initial moisture content decreases and the cement content or curing time increases. However, the axial strain at failure for cement-stabilized specimens decreased with increasing cement content or curing time. Furthermore, it is concluded that the increase in UCS of combined PPF or BF and cement inclusions is more than the increase caused by each of them, individually.