Effects of concrete composition on transmission length of prestressing strands

The bond behaviour of prestressing strands in precast pretensioned concrete members, and its transmission length, depends on several factors. However, no consensus exists on the main parameters to be considered in the expressions to predict the transmission length. Usually when the concrete properties are considered, only the concrete compressive strength is included. This study analyzes the influence of concrete composition made up of different cement contents and water/cement ratios on the bond behaviour in transmission of seven-wire prestressing strands. The bond properties and the transmission lengths have been determined. The results show that the influence of the water/cement ratio is very small for concretes with lows cement contents, but the influence of the water/cement ratio on the transmission lengths is highly significant when cement content is high. The effect of cement content in the transmission lengths can reveal different tendencies based on the level of the water/cement ratioThe content of this article forms a part of research that the Universitat Politecnica de Valencia's Institute of Concrete Science and Technology (ICITECH) is presently conducting in conjunction with PREVALESA and ISOCRON. This study was funded by the Ministry of Education and Science and ERDF (Project BIA2006-05521). The authors wish to thank the above companies as well as the concrete structures laboratory technicians at the Universitat Politecnica de Valencia for their cooperation. Also, the authors wish to pay their respects to C.A. Arbelaez.Martí Vargas, JR.; Serna Ros, P.; Navarro Gregori, J.; Bonet Senach, JL. (2012). Effects of concrete composition on transmission length of prestressing strands. Construction and Building Materials. 27(1):350-356. doi:10.1016/j.conbuildmat.2011.07.038S35035627