Transfer Length of CFRP/CFCC Strands for Double-T Girders

摘要

>Presents the results of an experimental investigation addressing the variations in transfer lengths in two types of carbon fiber reinforced polymer (CFRP) prestressing strands. Parameters such as the level of prestress at release, creep, and the rate and method of release of prestress are considered. In all, eight double-T (DT) prestressed girders fabricated with high strength concrete were tested. Four DT girders were prestressed with CFRP Lead/me tendons while the other four DT girders were prestressed with carbon fiber composite cable (CFCC) strands. Based on the experimental results, a proposed modification in an available model for predicting the transfer length of CFRP Leadline tendons and CFCC strands is suggested. A comparison of results for the transfer length obtained using the proposed modification with those of others is made. It is shown that the calculated and measured transfer lengths are in close agreement with those obtained by others in the case of Leadline tendons only. It is also noted that the level of release of prestress has no significant effect on transfer length.>References>1. Abdelrahman, A. A., Tadros, G., and Rizkalla, S. H., href=" http://dx.doi.org/10.14359/994 " title="a€?Test Model for First Canadian Smart Highway Bridge,a€?" target="_blank">a€?Test Model for First Canadian Smart Highway Bridge,a€? ACI Structural Journal, V. 92, No.4, July-August 1995, PP. 451-458. > 2. Shehata, F., Abdelrahman, A., Tadros, G., and Rizkalla, S. H., a€?FRP for Large Span Highway Bridge in Canada,a€? Proceedings of the U.S.-Canada-Europe Workshop, Recent Advances in Bridge Engineering, U. Meier and R. Betti (Editors), Zurich, Switzerland, 1997. > 3. ACT Committee 440, a€?Statea€”of-the-Art Report on Fiber Reinforced Plastic Reinforcement for Concrete Structures,a€? American Concrete Institute, Farmington Hills, MI, 1996, 153 pp. > 4. Mitchell, D., Cook, W. D., Khan, A., and Tham, T., a€?href="http://dx.doi.org/10.15554/pcij.05011993.52.66 " title="Influence of High Strength Concrete on Transfer and Development Length of Pretensioning Strand,a€?" target="_blank">Influence of High Strength Concrete on Transfer and Development Length of Pretensioning Strand,a€? PCI JOURNAL, V. 38, No. 3, 1993, pp. 52-64.> 5. Soudki, K. A., Green, M. F., and Clapp, F. D., href=" http://dx.doi.org/10.15554/pcij.09011997.78.87 " title="a€?Transfer Length of Carbon Fiber Rods in Precast Pretensioned Concrete Beams,a€?" target="_blank">a€?Transfer Length of Carbon Fiber Rods in Precast Pretensioned Concrete Beams,a€? PCI JOURNAL, V. 42, No. 5, September-October 1997, pp. 78-87.> 6. ACT Committee 318, a€?Building Code Requirements for Structural Concrete (ACI 318-98) and Commentary (ACI 318 R 98),a€? American Concrete Institute, Farmington Hills, MI, 1998. > 7. C. S. A. Standard CAN 3-A23.3-94, a€?Design of Concrete Structures for Building,a€? Canadian Standards Association, Rexdale, Ontario, Canada, 1994. > 8. Shahawy, M. A., Issa, M., and Batchelor, B. de V, href="http://dx.doi.org/10.15554/pcij.05011992.84.96 " title="a€?Strand Transfer Length in Full Scale AASHTO Prestressed Concrete Girders,a€?" target="_blank">a€?Strand Transfer Length in Full Scale AASHTO Prestressed Concrete Girders,a€? PCI JOURNAL, V. 37, No. 3, May-June 1992, pp. 84-96. > 9. Buckner, C. D., href=" http://dx.doi.org/10.15554/pcij.03011995.84.105 " title="a€?A Review of Strand Development Length for Pretensioned Concrete Members,a€? " target="_blank">a€?A Review of Strand Development Length for Pretensioned Concrete Members,a€? PCI JOURNAL, V. 40, No. 2, March-April 1995, pp. 84-99. > 10. Russell, B. W., and Burns, N. H., href="http://dx.doi.org/10.15554/pcij.09011996.44.65 " title="a€?Measured Transfer Lengths of 0.5 and 0.6 in. Strands in Pretensioned Concrete,a€? " target="_blank">a€?Measured Transfer Lengths