Evaluation of the effects of enzyme-based liquid chemical stabilizers on subgrade soils

Abstract

The purpose of this study was to asses the strength of enzyme treated soil material. Thus the aim of the paper is to present laboratory results on the effects of two enzyme-based liquid chemicals as soil stabilizers. Soil samples were prepared for standard geotechnical tests from two types of soils treated with the two enzyme-based products. One soil had a plasticity index of 35% and the other had a plasticity index of 7%. The maximum plasticity index reduction after treatment of both soils was less than 5 % and therefore not significant. A slight improvement in the maximum dry density was obtained following treatment by one product on one of the soil samples, but this is within experimental variability. Unconfined compressive strength was evaluated after the samples were left to cure in plastic bags for 7, 14, 28 and up to 56 days for one sample and revealed a mixed effect on strength. In those instances where there was an increase in strength it was less than 50 % with an increase in concentration level of the two enzyme-based stabilizers and age for both soils after treatment, which is practically not significant.