Experimental Study of the Impact of Porosity on Bio-Induced Cementation in Clay-Rich and Dolomite-Rich Rocks Using MICP

Biocementation using the microbial-induced carbonate precipitation (MICP) technique promotes the production of calcium carbonate (CaCO3) within the pores of geomaterials (rock and soil). However, there is still a lack of knowledge on the effect of pre-existing porosity on the biocementation in rocks from a mechanistic view. This work assessed the changes in mechanical properties of characteristically low porosity (clay-rich shale) and more porous (dolomitic) rocks due to MICP biocementation. We treated the rock samples using a microbial agent for a distinct period and temperature. Thereafter, the unconfined compressive strength (UCS) of the rock samples before and after biocementation was obtained. Finally, we analyzed the pre- and post-treatment changes in the samples to better understand the effect of MICP biocementation on the rock strength. The results indicate that in more porous rocks, MICP biocementation treatment will yield a higher increase in strength (+22%) than in ultra-low porous rocks (+13%) treated with MICP.