A STRUT AND TIE MODEL FOR FRCM-STRENGTHENED REINFORCED CONCRETE DEEP BEAMS

Exiting literature revealed that fabric reinforced cementitious matrix (FRCM) is a promising material for the strengthening of shear deficient reinforced concrete (RC) beams. However, most of the available experimental studies are devoted to the use of FRCM system for the strengthening of slender beams and limited literature is available on the strengthening of deep beams using FRCM system. Moreover, there is no available literature on the analytical modelling of FRCM-strengthened deep beams. In this paper, a simple strut and tie model (STM) has been used to predict the ultimate load carrying capacity of RC deep beams strengthened in shear using FRCM system. The model accounts for the internal transverse reinforcement ratio and axial rigidity of the FRCM system. The proposed model is validated against an experimental results of RC deep beams strengthened with different types of FRCM system available in the literature.现有文献研究表明，织物增强水泥基复合材料（fabric reinforced cementitious matrix, FRCM）是加固抗剪性能不足的钢筋混凝土（reinforced concrete, RC）梁的极具应用前景的材料。然而，现有绝大多数试验研究均聚焦于采用FRCM体系加固细长梁，针对采用FRCM体系加固深梁的相关文献较为匮乏。此外，目前尚无关于FRCM加固深梁的分析建模相关研究。本文采用简化桁架模型（strut and tie model, STM），预测采用FRCM体系进行抗剪加固的RC深梁的极限承载能力。该模型考虑了内部横向配筋率与FRCM体系的轴向刚度。本文通过现有文献中采用不同类型FRCM体系加固的RC深梁试验结果，对所提出的模型进行了验证。