Abstract
A new estimating method of concrete strength from pin penetration test using air pressure is proposed as a simple in-situ test of shotcrete strength. In procedure of this method, pins are driven on the surface of shotcrete by a conventional air pressure nailer. The compressive strength of shotcrete is estimated from the pin penetration depth. In the paper, the applicability of this method is verified through laboratory and field tests. There are intimate relationships between the pin penetration depth and the compressive strength in range of 1 to 30N/mm2. Therefore, it is found that the proposed new testing method is effective for estimating the shotcrete strength. Add to this, the merits of in-situ testing method serve the purpose of proposing a new control method on shotcrete strength.
