An Experimental Study on Influence of Concrete Strength and Cover Size on Transfer Length of Prestressing Strand in Pretensioned Prestressed Concrete Members

압축강도 및 피복두께에 따른 프리텐션 부재의 전달길이 변화에 관한 연구

In recent times, large strands have become increasingly popular in the pretensioned prestressed industry and have found wide applications in varying geometries of sections. However, use of such elements and their behavior in several situations have been questioned with respect to anchoring of these strands in concrete. In addition, the experimental results available on bond are limited and information relating to large strands is rare. This study was conducted to determine the influence of some of the inadequately examined properties on transfer length of prestressing strand. The principle variables considered were strand size, concrete strength and clear bottom cover. The experimental results indicate clearly that concrete strength at transfer and cover size influence transfer length significantly. An attempt was made to suggest prediction equation for transfer length including above parameters.