미생물을 혼입한 콘크리트의 전기적 염화물 침투 저항 및 강도 특성 평가

An Assessment of Properties on Electrical Chloride Penetration Resistance and Compressive Strength of Micro-organism Mixed Concrete

In recent years, river sand depletion has caused the increase of sea sand use. Chloride which exists in the sea sand promotes the rebar corrosion and causes degradation of durability in the RC concrete structures. In case of offshore RC structures, chloride causes the rebar corrosion and the salt damage which generates concrete cracks, although high quality river aggregates are used for the building construction. In this study, the concretes were produced by using a microorganism and the compressive strength test and the chloride ion penetration test were performed. Two tests(compressive strength, chloride ion penetration resistance) were carried out for performance evaluation of concrete. ${\phi}100mm{\times}200mm$ size specimens were made and 5 types of mixing water(2F-1, 5B, Urea medium, Marine broth medium and Ordinary water) were used to make concrete specimens and compressive strength test. All specimens were cured for 7, 28days. To evaluate chloride ion penetration resistance, ${\phi}100mm{\times}200mm$ specimens were cut and ${\phi}100mm{\times}50mm$ samples were prepared. The electrical chloride ion penetration testing method were performed in order to measure the chloride ion resistance and the test was progressed according to the contents of ASTM C1202-12. SEM and porosimeter analysis were performed in order to identify the microstructures of specimens. As a result of the tests, 2F-1 group had superior compressive strength and chloride ion penetration resistance to the others. Through this research, it was tried to examine the potential for reducing the defects of concrete and applying the micro-organism as a natural admixture material.