碳纤维增强复合网格-聚合物水泥砂浆加固RC梁的抗弯性能试验研究

为研究碳纤维增强复合(CFRP)网格和聚合物水泥砂浆(PCM)复合加固钢筋混凝土(RC)梁的抗弯性能，对5个RC梁试件进行抗弯性能试验，分析CFRP网格-PCM复合加固RC梁的抗弯破坏机理，研究网格不同层数和不同单位加固量对RC梁抗弯性能的影响。基于抗弯承载力的既有计算模型，引入剥离应变建立改良计算模型，并采用其他学者的9根FRP网格加固RC梁的受弯试验数据，验证改良计算模型的准确性。研究结果表明：CFRP网格-PCM对RC梁的抗弯加固效果明显，单位加固量较高的试件具有更高的承载能力，但其更易发生剥离破坏；在单位加固量相当的条件下，单层网格与双层网格呈现出相同的抗弯性能，双层网格重叠布置的加固方式是有效的；抗弯承载力的既有计算模型对试验结果拟合效果较差，所建立的改良计算模型拟合程度较好，能更好地反映CFRP网格-PCM复合加固层的实际受力状态。

Experimental study on flexural performance of RC beamsstrengthened with CFRP grid-PCM

To investigate the flexural capacity of reinforced concrete (RC) beams strengthened with a composite layer combining carbon fiber reinforced polymer (CFRP) grid and polymer cement mortar (PCM), five RC beams were tested with the number of FRP layers and ratio of strengthening material (i.e. FRP grid) as parameters. The failure mechanisms of RC beams strengthened with CFRP grid-PCM were analyzed to reveal the flexural strengthening performance. Based on the existing analytical model of flexural capacity of RC beams, an improved analytical model was established by considering the peeling strain of CFRP grids. The applicability of the model was then validated by comparing the test data of nine RC beams strengthened with FRP grid and tested by other researchers. The experimental results show that CFRP grid PCM works pretty well, and the specimens with high ratio of strengthening material have high load carrying capacities, but are prone to peeling damage. Specimens with one-layer or two-layer grids have the same flexural capacity with the same ratio of strengthening material, indicating that the bonding of two-layer grids is effective. Test results cannot be predicted by the existing calculation models in terms of flexural capacity, but the improved calculation model can provide relatively good prediction, and can better reflect the stress state of the CFRP grid-PCM composite.