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在花岗岩石梁受拉区嵌入CFRP筋以提高其抗弯承载力,对既有石结构加固和拓展现代石结构的应用范围具有重要意义。为研究石梁表层嵌埋CFRP筋组合石梁中CFRP筋、粘结剂与花岗岩的粘结性能,开展了26个直接拔出试件的试验研究。主要研究参数包括CFRP筋直径大小、CFRP筋嵌埋长度和粘结剂保护层厚度。试验现象揭示了3种典型破坏形式:CFRP筋拉断破坏、CFRP筋-粘结剂界面滑移破坏和石梁嵌埋槽角劈裂破坏。试验结果表明:1)试件破坏方式与嵌埋长度、CFRP筋表面粘结剂保护层厚度以及CFRP筋直径大小有关;2)CFRP筋表层粘结剂保护层最小厚度为0.5Db;3)极限荷载随着嵌埋长度的增加而增大,而平均粘结强度随着嵌埋长度的增加而减小;4)基本锚固长度与CFRP筋材直径有关,基本锚固长度与CFRP筋材直径的比值随直径的增加而有所增加。
Embedding CFRP tendons in the tension zone of granite beam to improve its flexural capacity is of great importance to the reinforcement of existing stone structures and the application of modern stone structures. In order to study the bond behavior of CFRP bars and adhesives with granite embedded in CFRP bars with stone beams embedded in the surface, a series of 26 direct pull-out tests were carried out. The main research parameters include the diameter of the CFRP tendons, the embedment length of the CFRP tendons and the thickness of the adhesive cover. The test phenomenon reveals three typical forms of failure: tensile fracture of CFRP tendons, slip failure of CFRP tendons-binder interface and corner fracture of rockfill embedded gutters. The test results show that: 1) the failure mode of the test piece is related to the embedding length, the thickness of the protective layer on the surface of the CFRP tendons and the diameter of the CFRP tendons; 2) the minimum thickness of the protective layer of the CFRP tendons is 0.5Db; 3) The load increases with the length of embedded, and the average bond strength decreases with the increase of embedded length; 4) The basic anchorage length is related to the diameter of CFRP, the ratio of the basic anchorage length to the diameter of CFRP Increases with increasing diameter.