This paper presents diagnosis method of concrete cavity at construction stage using the non-destruction technique. The non-destruction technique is schmidt hammer, elastic wave and thermographic camera.
conclusion
1. Presented regression curve is applicable to concrete design strength 18.0MPa and healthy portion concrete compressive strength 21.22MPa. If it is gathered the more data, from concrete surface to inner cavity of depth is calculated with schmidt hammer.
2. Because elastic wave pass the concrete inner, elastic wave disturbance occur. Contact pressure gap of departure-receiver happen doubtful about measuring data. So, it is difficult to grasp for cavity position and size.
3. Thermographic analysis grasp cavity position with effect and when atmosphere temperature is maximum temperature, thermographic is very distinctness.
4. Thermographic analysis useful to cavity position and schmidt hammer is useful to measure from concrete surface to cavity of depth.