This paper presents experimental and theoretical investigations on the flexural utilised of FRP (fibre-reinforced polymer) rebar-reinforced ECC (engineered cementitious composite) beams subjected to freeze–thaw cycles. Eight FRP-reinforced specimens after subjected to 0, 50, 100 and 150 cycles of freeze–thaw were tested to failure under flexural loading. Experimental results show that the moment capacity decreases with the increase of freeze–thaw cycles regardless of the material used, but the decreasing rate of the reinforced ECC specimen is lower than that of the conventional reinforced concrete specimen. The bearing capacity, deflection and crack width of the reinforced ECC specimens under quasi-permanent combination of moments are 1.13 ~ 1.21, 0.66 ~ 0.90 and 0.71 times of those of the conventional reinforced concrete specimens, respectively. Due to the excellent tensile and durability performance of ECC materials, bearing capacity, stiffness and crack resistance of FRP-reinforced ECC beams are enhanced compared with their conventional counterparts, particularly with more freeze–thaw cycles. Based on the formulae from ACI 440 and GB 50608, taking into account of the contribution of ECC material and balanced reinforcement ratio, the simplified formulae are developed to estimate the moment capacity and stiffness of the FRP-reinforced ECC beams. The results predicted on the moment capacity and deflection are in good agreement with the corresponding experimental measurements.

本文介绍了 FRP（纤维增强聚合物）钢筋增强 ECC（工程水泥基复合材料）梁在冻融循环下的弯曲利用的实验和理论研究。在经受 0、50、100 和 150 次冻融循环后，八个 FRP 增强试样在弯曲载荷下进行了破坏测试。实验结果表明，无论使用何种材料，弯矩承载力都随着冻融循环次数的增加而降低，但增强ECC试件的下降率低于常规钢筋混凝土试件。准永久组合弯矩下钢筋ECC试件的承载力、挠度和裂缝宽度分别是常规钢筋混凝土试件的1.13～1.21、0.66～0.90和0.71倍。由于 ECC 材料优异的拉伸和耐久性能，FRP 增强 ECC 梁的承载能力、刚度和抗裂性与传统梁相比有所提高，尤其是在更多的冻融循环下。基于ACI 440和GB 50608中的公式，考虑到ECC材料和平衡配筋率的贡献，开发了简化公式来估计FRP增强ECC梁的弯矩承载力和刚度。对弯矩承载力和挠度的预测结果与相应的实验测量结果非常吻合。特别是在更多的冻融循环中。基于ACI 440和GB 50608中的公式，考虑到ECC材料和平衡配筋率的贡献，开发了简化公式来估算FRP增强ECC梁的弯矩承载力和刚度。对弯矩承载力和挠度的预测结果与相应的实验测量结果非常吻合。特别是在更多的冻融循环中。基于ACI 440和GB 50608中的公式，考虑到ECC材料和平衡配筋率的贡献，开发了简化公式来估算FRP增强ECC梁的弯矩承载力和刚度。对弯矩承载力和挠度的预测结果与相应的实验测量结果非常吻合。