Use of lignocellulose-degrading enzyme bio-cemented soils in the construction industry

Abstract

In their activity, termites break down biomass into glucose, forming cementitious compounds. This results in rainfall-resistant mounds for their shelters, which interests the construction industry. This study explored the potential application of the abundant naturally bio-cemented termite mound soils in highway construction. Experimental investigations compared these mound soils to surrounding soils, revealing that mound soils are 68.2% finer in particle size distribution and have 81.4% lower organic content. Atterberg limits indicated 14.6% higher plasticity and a 5.3% increase in specific gravity for mound soils. Atomic Absorption Spectroscopy (AAS) showed no significant difference in chemical composition. Proctor tests indicated that the compaction characteristics of the soils were comparable, confirming their engineering viability without modifications. Mound soils exhibited a twofold increase in Unconfined Compressive Strength (UCS) and a 33.9% increment in California Bearing Ratio (CBR) strength. One-way ANOVA tests confirmed these differences with p-value ranges of 0.0056-0.0361 below the 0.05 significance threshold. The study advocates utilising eco-friendly naturally bio-cemented mound soils in highway construction, meeting minimum standards. Mound soils from one acre can construct up to 2,500m highway, optimising resource use, promoting sustainability by repurposing natural materials, and significantly reducing carbon emissions. Further research on soil improvement using lignocellulose-degrading enzymes is recommended.