中文摘要：

为探讨钢绞线网片-聚合物砂浆加固技术在桥梁加固中的可行性，开展了钢筋混凝土箱梁的加固试验研究。通过3根薄壁箱梁缩尺试件的纯弯加载试验，检验了该技术的加固效果，并对试件的位移、应变、裂缝扩展及破坏特征进行了比较和分析；研究了桥梁箱梁加固和建筑结构矩形梁加固的差异，对钢绞线网片-聚合物砂浆用于混凝土箱梁桥的加固提出了建议。结果表明：加固措施显著增大了箱梁的刚度，起到了抑制裂缝开展、提高屈服荷载和极限荷载的作用；加载过程中，箱梁的应变分布存在明显的剪力滞效应，加固梁的破坏始自剪弯区U型箍内侧砂浆面层的拉裂，并受到腹板弯剪裂缝萌生、扩展的影响；加固梁的最终破坏形态为砂浆-混凝土界面的剥离破坏，而钢绞线未被拉断，受压区混凝土也未出现压溃现象。

英文摘要：

In order to investigate the feasibility of steel stranded wire mesh and polymer mortar （SMPM） in the strengthening of bridge structures, experimental study of the reinforced concrete box-girders was carried out. The strengthening effect was verified through the bending tests on three scaled thin-walled box-girder specimens. Comparison and analysis were made on the displacements, strains, crack propagation and failure characteristics. Differences of strengthening of bridge box-girders and rectangular beams in building structures were discussed. Suggestions regarding application of the SMPM in the strengthening of bridge box-girders were given. Test results show that the structural stiffness is increased significantly with the crack propagation restrained by the strengthening measures. Increases in the yielding load and the ultimate load are also observed. Failure of the two strengthened girders both initiated from the tensile cracking of mortar at the inner side of the U-formed anchorage, which is influenced by the initiation and propagation of flexural shear cracks in the slabs. The failure mode is the debonding of the SMPM laminated from the concrete girders, while the steel wires are not ruptured in the test and no concrete crush in the compressive region of the top plate is observed.