Improving the dispersive soils with polypropylene fiber and lignosulfonate stabilizer

Document Type : Original Article

Authors

1 Islamic Azad University, Shiraz, Iran

2 Department of Civil Engineering, Zand-e-Shiraz higher Education Institute

3 Department Of Civil Engineering, Estahban Branch, Estahban, Iran

Abstract

The behavior of dispersive soils has caused serious damages to many structures, especially to dams and roads. Necessity to using the problematic soils has necessitated the improvements. In this study, improvement of dispersive soils with the lignosulfonate as a stabilizers and polypropylene as a reinforce fibers have been studied to assess the possibility of increasing the resistance to erosion and compressive strength of dispersive soils. For this purpose, double hydrometer test, pine-hole and unconfined compression tests has performed on modified dispersive clay. The results show that dispersive potential reduced by adding lignosulfonate. Adding polypropylene improves the strength of the soil. Although the reinforcing the soil with only polypropylene fibers cannot reduce the dispersive potential, the simultaneous usage of lignosulfonate and polypropylene leads to increasing erosion resistance and unconfined compression strength. Simultaneous improvement with 2% lignosulfonate and 0.35% polypropylene fibers significantly reduced the soil dispersity from 100% to 23%. Furthermore, this mixture changes the dispersive potential from high to non-dispersive conditions, increases the compressive strength of the soil after 7 days of curing almost 6 times bigger and after 28 days more than 25 times.

Keywords