Paper Title
Study the Effect of Bacillus Cereus on the Strength Characteristics of Rice Husk Ash Concrete

Abstract
The effect of Bacillus cereus on the mechanical properties of the concrete formed with 20% replacement of Rice Husk Ash to the weight cement is presented in the study. For the purpose of this study, a control mix was designed to have 28-day strength of 20 MPa in which cement was replaced with RHA by 20% of its weight. Then Bacillus cereus was introduced in the mix in the concentration of 5%, 10%, and 15%. Tests were for performed for compression strength, water absorption, and impact strength. Results showed that the introduction of the Bacillus cereus in the concrete improved its compressive strength to 33% than that of the control mix for 15% concentration of Bacillus cereus at 28 days of curing. Bacillus cereus of with the concrete reduced the water absorption from 2.4% to 1.7% at 15% concentration, confirming the calcite precipitation. Scanning Electron Microscopy and X-Ray Diffraction spectroscopy on the control sample and the sample with 15% Bacillus cereus broth at 28 days of curing exhibited the formation of additional CSH, calcite precipitation in the micro-pores and improved the microstructure of the concrete at 15% Bacillus cereus broth and made concrete matrix denser. All these findings indicated that the replacement of RHA with the introduction of Bacillus cereus improved the mechanical properties of concrete. Keywords - Bacillus cereus, Rice Husk Ash, Compression Strength, Scanning Electron Microscopy.