, Professor, Civil, Environmental and Geo-Engineering
A number of commercial enzyme solution products have been developed over the past years for which the manufacturers, based on limited laboratory and field data, advertise significant benefits for stabilization of pavement subgrades and other soil stabilization applications. This research studied the effect of two enzymes as soil stabilizers on two soil types to determine how and under what conditions they function. Researchers evaluated the chemical composition, mode of action, resilient modulus, and shear strength to determine the effects of the enzymes A and B on the soils I and II. The enzymes produced a high concentration of protein and observations suggest the enzymes behave like a surfactant, which affects its stabilization performance. The specimens were subjected to testing of varying lengths of time to determine their performance. Researchers observed an increase in the resilient modulus as the curing time increased, but that an increase in application rate, as suggested by manufacturers, did not improve the performance of the enzymes. The study also suggests noticeable differences between the two enzymes and their effects on the soils in terms of resilient modulus and the stiffness of the soil.