경량 콘크리트의 결함 크기에 따른 압축강도-초음파 상관관계 분석

초록

Lightweight aggregates are used as alternatives to normal aggregates to reduce the unit weight of concrete. Internal defects in lightweight concrete can be caused by lightweight aggregates, and the method for detecting internal defects is insufficient. In this study, an ultrasonic nondestructive test of lightweight concrete is performed, and the correlation between the defect size, compressive strength, and ultrasonic pulse velocity is analyzed by comparing the results of the compressive test. Solid bubble was used as lightweight aggregate, and various sizes of defects were implemented inside the specimens. The ultrasonic nondestructive test was performed according to the defect size of up to 30 curing days, and then, correlation was analyzed by measuring the compressive strength. The ultrasonic pulse velocity of lightweight concrete decreased by up to 23% and the compressive strength decreased by up to 41% as the defect sizes increased. This study confirmed the correlation between the ultrasonic pulse velocity and the compressive strength according to defect sizes and concluded that it is possible to predict defects inside lightweight concrete and mechanical performance by performing an ultrasonic nondestructive test.

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