Enhancement of Thermophilic (Geobacillus stearothermophilus) Cement–Sand Mortar Properties

Abstract

This study describes the incorporation method of Geobacillus stearothermophilus (ATCC 12978) inside the cement--sand mortar. Different cell concentrations of Geobacillus stearothermophilus were incorporated and the improvement in the properties of cement--sand mortar has been observed. Based on the study conducted, the involvement of Geobacillus stearothermophilus (ATCC 12978) has a positive impact to improve the performance of cement--sand mortar in terms of compressive strength and water absorption characteristic as compared to the controlled mortar. The incorporation of Geobacillus stearothermophilus has catalyst the occurrence of wollastonite (CaSiO3) that has proven capable to the enhanced concrete properties by modifying concrete pore structures. This study shows that the optimum concentration gives the most enhanced properties of the resulted cement--sand mortar as 1 {\texttimes} 109 cfu/ml. The current work demonstrates that the direct involvement of Geobacillus stearothermophilus in mortar has a great potential to enhance concrete performance in such natural way.