【摘要】 为研究冻融循环作用对CFRP加固混凝土梁疲劳性能的影响,以CFRP加固混凝土梁的疲劳试验作为对照,分别进行了CFRP加固受到冻融循环作用的混凝土梁的疲劳试验和CFRP加固梁经冻融循环作用后的疲劳试验.试验结果表明:在正常使用状态下,冻融循环50次作用后,CFRP加固梁的挠度增加了6.2%~14.9%,主筋应变增加了2.14%~11.2%,刚度变化不显著;在相同疲劳荷载作用下,与未经冻融作用的CFRP加固梁相比,经受冻融循环作用的CFRP加固梁的疲劳寿命降低不到5%;CFRP加固受到冻融损伤的混凝土梁可能发生剥离破坏,因而在工程中,为防止发生剥离破坏应采取有效措施.更多还原

【Abstract】 In order to study the effects of freeze-thaw cycling action on the fatigue behavior of CFRP-strengthened beams,three CFRP(carbon fiber reinforced polymer)-strengthened beams were tested under fatigue loading.One of the beams was a control beam and it was not subjected to freeze-thaw cycles.The remaining two beams underwent freeze-thaw cycling before or after being strengthened,respectively.The main results obtained from the tests are: in normal service state,the deflection increases 6.2% to 14.9%,and the steel strain increases 2.14% to 11.2%,and the stiffness decreases slightly in CFRP-strengthened beam after 50 freeze-thaw cycles;under the same fatigue loading,a slight drop(less than 5%)in fatigue life is observed in strengthened beam with freeze-thaw cycling action compared with the control beam;the debonding failure mode may occur in the beam subjected to freeze-thaw cycles before being strengthened with CFRP.So in this case some measures should be adopted to avoid debonding failure.更多还原