Possible use of paddy husk ash in improvement of engineering characteristics of peaty clay

Abstract

Deferent types of consolidation techniques have been used to improve the engineering characteristics of peaty clays encountered in highway projects in Sri Lanka. The main drawback in these techniques is the long time duration required in the case of thick deposits. Mixing with cement as an alternate improvement technique had been studied at University of Moratuwa successfully in the laboratory. Considering the high cost involved in mixing cement, this research attempts to study the use of another pozzolonic materialpaddy husk ash (PHA)(Also known as Rice Husk Ash (RHA) - that is widely available as a waste product. In this research, to assess the improvement of strength and compressibility, different mix proportions were tried out. Improvements were assessed by conducting consolidation tests and unconsolidated undrained triaxial tests. Test results showed that PHA alone is not as effective as cement as a binder but can be used in combination with cement.