The use of gram-negative Bacillus bacteria as an additive in reactive magnesium oxide cement for stronger concrete

Abstract

This project aims to study the influence of Bacillus in enhancing the mechanism of hydration of reactive magnesium oxide (RMC) and hence, the rate of carbonation to ultimately forms more HMCs to give rise to higher strength. Bacillus is theorized to provide additional nucleation sites for the hydration of MgO to take place by giving an increased contact area for MgO and H2O molecules for hydration and more brucite formation. Any changes in hydration mechanism due to the addition of bacillus are studied with the following methodologies covered in this paper such as Isothermal calorimetry, TGA, XRD, and SEM for both hydrated and carbonated samples. These samples are then tested for the compressive strength test. This project will explore if bacillus does increase the strength of RMC using the cement mix design proposed and will include explanations. This will then prove if bacillus could be used as one of the mechanisms to improve the strength-gain mechanism of RMC.