二次受力下FRP筋内嵌加固混凝土梁抗弯承载力分析

Analysis for flexural capacity of reinforced concrete beams strengthened with near-surface mounted FRP bars considering effect of secondary loading

为研究二次受力对纤维增强塑料筋(FRP)内嵌加固(NSMR)混凝土梁抗弯极限承载力的影响,通过5根混凝土梁的静力加载试验,对在不同二次受力程度影响下的内嵌加固梁极限弯矩进行了研究.分析结果表明:随着初始弯矩的增大,对加固梁的极限承载力影响程度越大,由于不考虑二次受力影响所引起的计算误差就越大,所以当被加固梁的初始弯矩处于开裂弯矩区间时,可忽略二次受力带来的影响;当初始弯矩超过开裂弯矩时,则二次受力的影响不可忽略.

For studying the influence of flexural ultimate capacity which the fiber reinforced plastic rebar （FRP） near-surface mounted reinforce （NSMR） concrete beams considering secondary loading. Five reinforced concrete （RC） beams were tested by static loading, ultimate moment was studied considering different influence degree of secondary loading. The analysis results show the greater degree of influence on the ultimate capacity of the reinforced beam with the increase of initial moment. The calculation errors which ignore the secondary loading are lager. When the initial moment is at the range of cracking moment, the effects of secondary loading can be ignored. When the initial moment is lager than the cracking moment, the influence of secondary loading should not be neglected.