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2 - 附录A 科技文献翻译 原文 HYPERLINK /science?_ob=PublicationURL_cdi=5702_pubType=J_auth=y_acct=C000050161_version=1_urlVersion=0_userid=1002874md5=cb49fc38603a573d7e3a632eb3bfa307 Construction and Building Materials  HYPERLINK /science?_ob=PublicationURL_tockey=%23TOC%235702%232007%2399978999423FLA%23_cdi=5702_pubType=Jview=c_auth=y_acct=C000050161_version=1_urlVersion=0_userid=1002874md5=893c5a113ea14f9cac285e3e5e7b4025 Volume 21, Issue 5 , May 2007, Pages 1052-1060 An approach to determine long-term behavior of concrete members prestressed with FRP tendons Abstract The combined effects of creep and shrinkage of concrete and relaxation of prestressing tendons cause gradual changes in the stresses in both concrete and prestressing tendons. A simple method is presented to calculate the long-term prestress loss and the long-term change in concrete stresses in continuous prestressed concrete members with either carbon fiber reinforced polymer (CFRP) or aramid fiber reinforced polymer (AFRP) tendons. The method satisfies the requirements of equilibrium and compatibility and avoids the use of any empirical multipliers. A simple graph is proposed to evaluate the reduced relaxation in AFRP tendons. It is shown that the prestress loss in FRP tendons is significantly less than that when using prestressing steel, mainly because of the lower moduli of elasticity of FRP tendons. The long-term changes in concrete stresses and deflection can be either smaller or greater than those of comparable girders prestressed with steel tendons, depending on the type of FRP tendons and the initial stress profile of the cross-section under consideration. Keywords: Creep; FRP; Long-term; Prestress loss; Prestressed concrete; Relaxation; Shrinkage Nomenclature A area of cross section d vertical distance measured from top fiber of cross section E modulus of elasticity age-adjusted elasticity modulus of concrete fpu ult