For the purpose of evaluating the strength of high-strength concrete, the strength of small diameter core was compared with 100, 50, and 30 mm cores. In case of high strength concrete, the smaller the core diameter, the lower the strength was. It is probably due to the disturbance of specimen during coring. Therefore, it is considered that it is difficult to apply in the field.

The purpose of this study is to development inspection, diagnosis and utilizing manual for facilities such as bridges, tunnels, and buildings. For this, firstly, the classification system about inspection and diagnosis equipment was established and that was divided in accordance with the intended use(durability, safety, equipment, environment). based on this, the manual was developed including specification, performance of equipment and using, managing and controling for the inspection and diagnosis work.