Durability study on reinforced concrete axial members retrofitted with fibre-reinforced cementitious matrix (FRCM)**********

纤维增强水泥基体（FRCM）加固钢筋混凝土轴杆的耐久性研究************

• 批准号: 537318-2018
• 负责人: ELREFAI, AHMED
• 金额: $ 1.82万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Engage Grants Program
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=650000
• 关键词: Durability; study; reinforced; concrete; axial

Fabric-reinforced cementitious matrix (FRCM) is a retrofitting system that has been introduced recently to retrofit/strengthen reinforced concrete (RC) structures. FRCM consists of one or more layers of anti-corrosive textiles made of carbon, glass, or Polyparaphenylene benzobisoxazole (PBO) grids that are sandwiched between layers of cementitious mortars. Unlike the epoxy-based fiber-reinforced polymers, mortars used in FRCM systems inherit the compatibility between the system and the concrete substrate since both materials have the cement as a common "base". To date, no data is available on the aging performance of FRCM-wrapped RC elements under the combined effect of axial loading and the exposure to harsh environmental conditions. The proposed research aims at examining such performance through a series of laboratory tests that will be conducted on RC prisms and cylinders wrapped with FRCM and tested under axial loads. The test parameters include the specimen's cross section (square and circular), the type of FRCM systems (2 types), the number of FRCM layers (1 or 2 layers), the specimen's condition prior to wrapping (conditioned or unconditioned), and the exposure condition after wrapping, which include (1) freeze-and-thaw cycles, (2) high temperatures, (3) humidity and high temperatures, (4) alkali solution, and (5) saltwater. Unconditioned specimens will be tested for reference. Specimens will be instrumented with strain gauges and/or compressometers to monitor the loads and strains during the test until failure occurs. Experimental results in terms of capacity, debonding, straining, modulus, and ductility will be recorded. The effect of different exposures on such quantities will be determined and verified against the provisions of ACI-549.4R-13. The results would be used to develop conceptual design rules for FRCM systems, which consider the effect of environmental aging in RC compression members such as columns and walls.

纤维增强水泥基复合材料（FRCM）是近年来发展起来的一种用于加固钢筋混凝土结构的加固体系。FRCM由一层或多层由碳、玻璃或聚对苯撑苯并双恶唑（PBO）网格制成的防腐蚀织物组成，这些网格夹在水泥砂浆层之间。与环氧基纤维增强聚合物不同，FRCM系统中使用的砂浆继承了系统和混凝土基材之间的相容性，因为两种材料都有水泥作为共同的“基础”。到目前为止，没有数据可用于在轴向载荷和暴露于恶劣环境条件的综合影响下的FRCM包裹RC元件的老化性能。拟议的研究旨在通过一系列的实验室测试，将进行钢筋混凝土棱柱体和圆柱体包裹FRCM和轴向载荷下进行测试，以检查这样的性能。试验参数包括试样的横截面（正方形和圆形），FRCM系统的类型（2种），FRCM层的数量（1或2层），包装前的样本状况（调节或未调节），以及包裹后的暴露条件，包括（1）冻融循环，（2）高温，（3）湿度和高温，（4）碱溶液;（5）盐水。将对未经处理的样本进行试验以供参考。将使用应变计和/或压缩计对样本进行测量，以监测试验期间的载荷和应变，直至发生失效。将记录关于承载力、脱粘、应变、模量和延性的试验结果。将根据ACI-549.4R-13的规定确定和验证不同暴露对这些数量的影响。研究结果将用于制定FRCM系统的概念设计规则，该规则考虑了环境老化对RC受压构件（如柱和墙）的影响。