新型复合材料“高强钢绞线网/ECC约束素混凝土”受压性能试验研究

考虑混凝土强度、工程水泥基复合材料(ECC)强度和横向高强钢绞线配筋率等因素，研究新型复合材料“高强钢绞线网/ECC约束素混凝土”(以下简称HSE约束素混凝土)的受压性能。HSE约束素混凝土轴心受压试验显示，达到最大荷载的30%左右时，约束层ECC出现约为0.01 mm的竖向裂缝；约为最大荷载的85%时，表面最大裂缝宽度约为0.07 mm；达到最大荷载时，最大裂缝宽度仅为0.20 mm；说明该新型复合材料具有很好的裂缝分散和控制能力。之后荷载缓慢下降至最大荷载75%左右，第一根横向钢绞线断裂；达到破坏时裂而不碎，约束层和核心混凝土未发生黏结破坏，完整性良好。HSE约束素混凝土与素混凝土相比，其开裂应力提高了88%~116%；轴心抗压强度提高了21%~49%、轴心压应变增加了约45%；极限压应变提高了106%~175%。ECC强度和混凝土强度及横向钢绞线配筋率的提高，均增大其开裂和最大荷载及极限压应变。 

Experimental study on compressive performance of new composite material “concrete confined with high-strength steel stranded wire meshes/ECC”

The compressive performance of new composite material “concrete confined with high-strength stainless steel stranded wire meshes/ECC” (hereinafter referred to as HSE confined concrete) was studied by considering the effects of parameters: concrete strength, strength of engineered cementitious composites (ECC) and reinforcement ratio of lateral high-strength stainless steel stranded wires. The axial compression test of HSE confined concrete shows that vertical cracks about 0.01 mm appears on ECC in constraint layer at about 30% of the peak load. When the applied load reaches about 85% and 100% of the peak load, the maximum crack width on the surfaces is about 0.07 mm, 0.20 mm, respectively. These phenomena show that the new composite material has excellent crack dispersion and crack-controlling ability. When the applied load decreases to 75% of the peak load, the first lateral steel stranded wires rupture for the first time. The HSE confined concrete specimens are cracked without breaking when completely destroyed, and maintain a good bond between the constraint layer and core concrete, which has a good integrity. Compared with the plain concrete column, the cracking stress, axial compressive strength, the axial compressive strain and ultimate compressive strain of HSE confined concrete are increased by 88%-116%, 21%-49%, 45%, 106%-175%, respectively. The increases of ECC strength, concrete strength grade and the reinforcement ratio of lateral steel stranded wires have improved the cracking load, peak load and ultimate compressive strain of HSE confined concrete.