Abstract
This work aimed to study the effectiveness of liquid asphalt in the enhancement of gypseous soils properties. This enhancement is by reducing the effect of water on gypsum particles and increasing strength parameters.
The work included two types of treatments firstly is by mixing technique and the second type is by grouting technique.
The testing program included the determination of unconfined compressive strength, shear strength and collapsibility parameters of untreated and treated gypseous soil with different percent of liquid asphalt.
The test results showed that the maximum unconfined compressive strength and the shear strength of soil increased to an optimum value and then decreased with increasing liquid asphalt.
The study concluded that the mixing technique was better than the injection technique because the mixing technique will cover the particles with a film of asphalt while the injection fills the voids of soil with asphalt. Moreover the results show that the oblique injection gives more strength to the soil than normal injection.
Keywords: Gypseous soil, Liquid asphalt, Soil improvement, Grouting, Injection
