Geotechnical characterisation of recycled EICP stabilized earthen materials

The use of earth materials, in the construction industry has gained increasing attention due to their sustainability and environmentally friendly properties. However, a major challenge remains in enhancing the material’s strength and durability through ecological stabilization methods that avoid energy-intensive processes and the use of conventional chemical binders, such as cement or lime. Among the various alternative eco-friendly stabilization techniques, recent studies have highlighted the potential of the Enzyme-Induced Calcium Precipitation (EICP) technique which relies on the catalytic action of the urease enzyme to hydrolyse urea, leading to the precipitation of calcium carbonate, forming the desired binding agent. Despite promising results from EICP stabilization, few studies have focused on the recyclability potential of stabilized earth or on how recycling affects key geotechnical properties such as grain size distribution, plasticity, or strength. This study presents a preliminary assessment of the recyclability potential of EICP-treated soils. It compares the geotechnical properties – such as particle size distribution and Atterberg limits – of recycled soil mixtures with those of the original soil to evaluate any changes induced by the recycling process. The findings of this study offer insights into the recyclability of EICP-treated earth materials and address potential environmental concerns related to their disposal.