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采用纤维编织网增强混凝土(TRC)这种新型材料对结构进行修补加固不仅可以改善结构的性能,而且可以几乎不增加结构的截面尺寸。为了评估TRC增强钢筋混凝土构件的抗裂能力,分别对14根不同情况的梁进行弯曲试验。结果表明,在钢筋混凝土梁配筋率一定的情况下,提高TRC层中的配网率可以有效地延缓梁上主裂缝的发展,减小裂缝的宽度和间距;纤维编织网的表面粘砂处理能更好发挥纤维编织网的约束能力,从而有效减小梁受拉区底面的最大裂缝宽度。精细混凝土中掺加聚丙烯纤维有助于提高梁的起裂荷载和减小梁正常使用阶段的裂缝宽度,有助于改善精细混凝土的韧性。新老混凝土界面植入U型抗剪销钉可以提高增强后梁的整体刚度,从而提高其抗裂性能;而涂抹界面剂的作用不明显。最后,基于钢筋混凝土结构的裂缝间距和宽度计算理论,定性地分析了纤维编织网对钢筋混凝土结构裂缝计算中控制参数的影响。
The use of new materials such as fiberglass reinforced concrete (TRC) to repair and reinforce structures not only improves structural performance but also increases structural cross-sectional dimensions with little or no increase. In order to evaluate the crack resistance of reinforced concrete members strengthened by TRC, bending tests were conducted on 14 different beams. The results show that increasing the distribution rate in the TRC layer can effectively delay the development of the main cracks on the beam and reduce the width and spacing of the cracks under the condition of a certain reinforcement ratio of the reinforced concrete beam. Can better exert the restraining ability of the fiber braid, thereby effectively reducing the maximum width of the crack in the bottom of the tension zone of the beam. The incorporation of polypropylene fiber into the fine concrete helps to improve the cracking initiation load of the beam and reduce the crack width during the normal use of the beam, which helps to improve the toughness of the fine concrete. Implantation of new-type concrete interface with U-shaped shear pins can enhance the overall rigidity of the reinforced rear beam, thereby improving its anti-cracking performance; and apply the interface agent is not obvious. Finally, based on the theory of crack spacing and width calculation of reinforced concrete structures, the influence of fiber braid on the control parameters in the crack calculation of reinforced concrete structures is qualitatively analyzed.