Impact of magnesium chloride on the mechanical properties of innovative bio-mortar

The present work aimsat studying the effect of different MgCl2 concentrations on the mechanical properties of bio-mortar. Calcium/Magnesium chloride (Ca/MgCl2) mixtures with molar (M) ratios of 1/0, 0.75/0.25, 0.5/0.5, 0.25/0.75 and 0/1 Ca/MgCl2 were tested for their abilities to consolidate sand by mixing with 1 M urea and bacterial cells (Sporosarcina pasteurii) with 2.4 optical density at 600 nm (OD600). The results showed that, the compressive strength of the prepared bio-mortar decreases with the increase of MgCl2 concentration. This is mainly due to the change in the type and crystallinity of the precipitated mineral by bacterial cells within sand grains.