Effect of Crack Repair by Bio-Based Materials Using Alginate and Bacillus Subtilis under Wet and Dry Environment Part-II

. This study examined durability of mortar after repairing crack using alginate gel films (1.5 wt.%) mixed with healing agents under seawater splayed condition. The healing agents consist of Bacillus subtilis (natto) as an aerobic microorganism and glucose as an organic carbon source, thereby producing insoluble calcium carbonate in the gel films in the presence of calcium ions. In this study, repaired mortar was dried under room condition for half year and exposed at seawater splayed condition for another half year. After that, surface condition, elastic wave velocity was measured. In addition, the inside situation in the crack was observed by X ray computed tomography. Based on the results of elastic wave velocity, the property of repair material in mortar was improved under the seawater splayed condition. Additionally the substance in crack derived from healing agents was remained even after seawater splayed exposure.