Reliability of transmission length estimation from strand end slip

[EN] An experimental program on twelve series of specimens with different embedment lengths to determine the transfer length was conducted. Transfer length test results of seven-wire strand on twelve different concrete mixtures were analyzed. A testing technique based on the analysis of bond behaviour by means of measuring the force supported by the tendon has been used. The specimens had been instrumented with slip measurement devices at each end of the specimen. A sequence of slip values at each end of the specimen after release versus the embedment length has been analyzed. The expressions relating the transfer length to the tendon end slip are presented. A value of Guyon's factor for tendon stress distribution shape has been obtained. Two criteria to determine the transfer length from the slip sequences at both ends of the specimens have been analyzed.