海洋大气环境下TRC加固RC梁受弯时变性能

为预测海洋大气环境下纤维编织网增强混凝土（textile reinforced concrete，TRC）加固RC梁剩余受弯承载力，对TRC加固RC梁受弯时变性能进行研究。基于材料时变性能，建立了TRC加固RC梁受弯承载力时变计算模型，在验证此模型可靠性基础上，通过9根TRC加固RC梁进行参数分析，研究TRC厚度（25、35、45 mm）、钢筋直径（12、14、16 mm）、纤维编织网层数（1~3层）等因素对TRC加固RC梁起锈时间、开裂时间、剩余受弯承载力的影响规律。结果表明：海洋大气环境下TRC加固RC梁受弯承载力随服役时间增加非线性降低，但是其退化速率小于普通RC梁的；增加TRC厚度可以有效延迟起锈时间和减少承载力降低幅度，当TRC厚度由35 mm增加至45 mm时，TRC加固RC梁的起锈时间分别为23.9 a和39.5 a，承载力降低幅度分别为27.48%和15.57%（服役60 a）；钢筋直径对起锈时间无影响，对开裂时间的影响也较小；当钢筋直径分别为12、14、16 mm时，经过60 a服役期后TRC加固RC梁剩余受弯承载力均较接近；增加纤维编织网层数可减小加固梁锈蚀后受弯承载力退化。

Time-dependent behavior of RC beams strengthened with TRC in marine atmosphere environment

In order to predict the residual bearing capacity of RC beams strengthened by TRC under marine and atmospheric environment, the time-varying behavior of TRC strengthened beams was studied. A time-varying calculation model of TRC strengthened beam was established and verified. Nine strengthened RC beams were used for parametric analysis. The effects of TRC thickness (25 mm, 35 mm, 45 mm), steel diameter (12 mm, 14 mm, 16 mm), textile layers (one layer, two layers, three layers) on the rust time, the cracking time and the residual flexural bearing capacity were studied. The results show that the flexural capacity of TRC strengthened RC beams decreases nonlinearly with the increase of service time, but the degradation rate is less than that of RC beams. Increasing the thickness of TRC can effectively prolong the rust time and reduce the decreasing magnitude of bearing capacity. When the TRC thickness increases from 35 mm to 45 mm, the rust time of TRC strengthened beams is 23.9 a and 39.5 a, respectively, and the bearing capacity decreases by 27.48% and 15.57%, respectively (60 years in service). The diameter of steel has no effect on rust time and little effect on cracking time. When the diameters of steel are 12mm, 14mm and 16mm, the residual flexural capacities of TRC strengthened beams after 60 years is close to each other. Increasing the number of textiles can reduce the decreasing magnitude the flexural capacity of TRC strengthened beams.