일방향 철근 콘크리트 슬래브의 폭발 피해 분석을 위한 최적의 비파괴검사법에 관한 연구

It is necessary to analyze on the compressive strength among material properties of concrete for confirming damages of architectures due to large explosion. A non destructive test is known as the representative methods estimating compressive strength and ultrasonic pulse velocity, rebound hardness test are widely used because of their simplicity, convenience. But combined method supplementing two types is applied at now as they are affected by the characteristics of test specimen. In this research to check damages on the members of structure before and after explosion, the characteristics of compressive strength are compared and analyzed through a real explosion test prior to full scale structures. The test results showed that the larger the TNT powder and the shorter the distance, the greater the decrease in strength before and after the explosion and that the largest displacement and moment for the explosive load and the greatest decrease in the strength at the central part. Due to the surface condition and the thickness variation of the concrete specimens, the standard deviation value is the smallest in the combining method of fusion of the ultrasonic method and rebound hardness method. Thus, the combining method can be one of appropriate methods to evaluate the strength in the reinforced concrete structures damaged by the explosion