Abstract

This study examined durability of mortar after repairing crack using alginate gel films (1.5wt.%) 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.

Abstract

Abstract

Composite panels were produced using film stacking procedure: a dry layer of fabric and two layers of matrix were piled up alternately and compression molded. The matrices used were PLA or PHB and the fabric was a cotton twill fabric without any chemical pre-treatment or treated with an epoxy functional oligomeric acrylic polymer (J). The PLA-based composite had clearly better mechanical properties than the pure matrix, namely +75%, +39% and +45% for elastic modulus, elongation at break and tensile strength, respectively. The PHB gave dramatic results reaching increases of +103%, +83%,+104% of the same three parameters. The J additive employed in the PLA gave no substantial changes but reduced the elongation at break. The same J additive in the PHB-based composite apparently increased the adeshion between matrix and fabric, showing an modulus and strenght increase with a reduction of elongation at break.