纤维网格增强超高韧性水泥复合材料加固混凝土圆柱受压性能试验

Experimental study of compression performance of concrete cylinder strengthened by textile reinforced engineering cement composites

为提升纤维增强聚合物复合材料(FRP)在加固材料中的优势和发挥效率,同时克服传统纤维网格增强砂浆的抗裂性差的缺点,将超高韧性水泥基材料(ECC)替代砂浆作为FRP网格无机黏结剂的新型复合材料已被提出,但仍缺乏相关的基础研究。本文以新型聚乙烯型ECC为基材,重点研究FRP grid/ECC加固混凝土柱的加固机制。以标准混凝土圆柱为试验对象,采用新型ECC材料为基材的FRP grid/ECC复合材料,以不同强度素混凝土、不同网格材料(玄武岩纤维增强聚合物复合材料(BFRP)与碳纤维增强聚合物复合材料(CFRP)网格)为试验变量,研究了该加固方式下对混凝土轴心受压性能的影响。试验结果表明,该加固方法可有效改善素混凝土脆性压溃破坏模式,提高峰值强度及受压延性。基于FRP grid/ECC材性特征,提出两阶段FRP grid/ECC加固机制,并基于该机制提出加固素混凝土圆柱承载力计算方法。

In order to make full use of fiber reinforced polymer(FRP)in retrofitting and overcome the poor anticracking property of textile reinforced mortar,a new composite was developed,where the engineering cement composite(ECC)replaces the mortar as the inorganic adhesive to bond the FRP textile,while,it still lacks of fundamental researches on the mechanism for retrofitting.Taking polyethylene type ECC as substrate,the mechanism for strengthening concrete columns by FRP grid/ECC was focused.The experimental study was conducted for standard concrete cylinder,strengthened by FRP grid/ECC where new ECC material was served as the matrix.The testing variables were plain concrete strength and different textile grid,i.e.basalt fiber reinforced polymer(BFRP)and carbon fiber reinforced polymer(CFRP)grid.The uniaxial compressive performance was studied.The test results show that the new strengthening method can improve the crushing failure mode,and enhance the compression strength and ductility.Based on the material property of FRP grid/ECC,the two-phase strengthening mechanism was proposed in this study,for the development of method to predict the compression capacity of FRP grid/ECC strengthened concrete cylinder.