高强不锈钢绞线网/ECC约束混凝土抗压强度

Compressive strength of concrete confined by high-strength stainless steel stranded wire meshes and engineered cementitious composites

将高强不锈钢绞线网/超高韧性水泥基复合材料(ECC)用于约束高强混凝土(简称HSME约束高强混凝土),并考虑混凝土强度(C55~C75)、ECC强度及横向钢绞线配网率等,开展其受压性能的试验和理论研究.由轴压试验可知:当HSME约束高强混凝土达到开裂荷载、85%的峰值荷载和峰值荷载时,最大裂缝宽度分别为0.02,0.08,0.20 mm,表现出极好的裂缝控制能力;破坏时整体裂而不碎,约束层和核心混凝土黏结良好.与素混凝土相比,HSME约束高强混凝土抗压强度、延性和变形能力显著增高.增大ECC强度和混凝土强度可增大其开裂荷载及峰值荷载,增大横向钢绞线配网率可增加其延性.引入ECC及横向钢绞线特征值,建立了HSME约束高强混凝土抗压强度计算模型,并通过对比本试验和其他试验的结果,验证了该模型的有效性.

High-strength stainless steel stranded wire meshes and engineered cementitious composites(ECC),HSME confined high-strength concrete for short,were applied to confining high-strength concrete,and the experimental and theoretical studies on compressive properties of the confined concrete were carried out,considering the effects of the ECC strength,reinforcement ratio of lateral steel stranded wires and concrete strength.Test results show that the maximum crack width of HSME confined highstrength concrete at the cracking load,85%of peak load and peak load are about 0.02,0.08 and 0.20 mm,respectively,which indicates the excellent crack control capability.The specimens are cracked without splitting at failure,and no interfacial bond failure is found between the constraint layer and core concrete.The compressive strength,ductility and deformation ability of HSME confined high-strength concrete are significantly improved compared with plain concrete.The cracking load and peak load increase with the increase of the ECC strength or concrete strength.The ductility increases with the increases of the reinforcement ratio of lateral steel stranded wires.A calculation model of the compressive strength of HSME confined high-strength concrete was developed by introducing the characteristic values of ECC and lateral steel stranded wires.The model was verified to be acceptable by the results in this paper and other experiments.