Estimation of Compressive Strength and Member Size of Steel Fiber Reinforced Concrete Using Stress Wave-Driven Nondestructive Test Methods

Among fiber-reinforced composites, steel fiber has been widely-used for concrete infrastructure such as silos, tunnels, specifically aiming at reducing the weight of concrete and enhancing its strength by overcoming the brittleness. However, there is still little known about appropriate quality management and applicability assessment for steel fiber composites. This study fills this knowledge gap by testing the possibility of maintenance through steel fiber concrete thickness estimation and assessing the applicability of the quality management instrument. To this end, this study utilizes two different stress wave-driven non-destructive test methods: ultrasonic pulse velocity and impact-echo methods. The ultrasonic pulse velocity method was employed to estimate the compressive strength of steel fiber reinforced concrete, while the impact-echo method was applied to estimate the thickness of various steel fiber reinforced concrete members. As a quality management factor of concrete, correlations between steel fiber mixing ratios and compressive strengths were experimentally explored and validated by error ratios for twenty-four specimens. The reliability was relatively high overall. The average error rate of all the specimens with steel fiber mixing ratios of 0, 0.75 and 1% was 3.36%. Accordingly, the results prove the applicability of the non-destructive test methods for building quality management.