Adding Aluminum Oxide to Improve the Repairing Effect of Cracks Based on Bio-Remediation

Abstract

A novel method of adding aluminum oxide to improve the efficiency of bio-remediation was evaluated. Aluminum oxide, at various amounts, was added to the medium to obtain a change in pH and urease activity. Urea and calcium salts with various amounts of aluminum oxide, were mixed with an absorbance-fixed bacterial suspension to analyze the effect of the method on production rates for calcium carbonate. Concrete specimens in which precracking was induced were subjected to bio-remediation with different amounts of added aluminum oxide. Adding aluminum oxide can decrease the pH of the environment, providing a more suitable micro environment and improving urease activity of bacteria. Moreover, the method can increase the adsorption of germs to increase the utilization rate of urea and production rate for calcium carbonate. After repairing, those with added aluminum oxide were better repaired and their strengths were higher. Therefore, the method can accelerate the bio-remediation reaction and reduce repairing time.