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以碳纤维复材约束混凝土为研究对象,探讨盐水干湿环境对其抗压性能的影响。基于亚热带气候特征,设计了盐溶液干湿循环加速老化试验系统。制作了5组共60个尺寸为150 mm(直径)×300 mm(高度)的混凝土圆柱体试件。试验试件按5种干湿循环作用次数(0,60,120,240,360次)进行分组,承受每种循环次数的试件由4种不同层数的碳纤维复材(0,1,2,3层)包裹约束,每种条件制备3个相同的试件。通过实施轴向压缩试验,分析了碳纤维复材约束混凝土经受干湿环境作用后的破坏模式、应力-应变曲线、抗压强度和极限压向应变的变化规律。试验结果表明:经受盐溶液干湿循环后的素混凝土圆柱抗压性能有所提高,而碳纤维复材约束混凝土圆柱的抗压性能下降;与未经受干湿环境作用的试件相比,经过360次干湿循环后,素混凝土圆柱的抗压强度提高9.38%,而包裹1、2、3层碳纤维复材约束混凝土圆柱的抗压强度分别下降12.10%、10.81%、13.88%。
Taking carbon fiber reinforced concrete confined concrete as the research object, the effect of brine wet and dry environment on its compressive properties was discussed. Based on the subtropical climatic characteristics, a salt-wet-dry cycle accelerated aging test system was designed. A total of 60 concrete cylindrical specimens with a size of 150 mm (diameter) × 300 mm (height) were produced. The test specimens were grouped according to the number of wetting and drying cycles (0, 60, 120, 240, and 360), and the specimens subjected to each cycle were covered by four kinds of carbon fiber composites (0, 1, Three identical specimens were prepared for each condition. Through the axial compression test, the failure modes, stress-strain curves, compressive strength and ultimate compressive strain of CFRP-constrained concrete subjected to dry-wet environment were analyzed. The experimental results show that the compressive strength of plain concrete columns after salt-water wet-dry cycles has been improved, while the compressive properties of concrete-filled cylindrical columns with carbon fiber composite materials have been reduced. Compared with the specimens without dry-wet environment, After the second wet-dry cycle, the compressive strength of plain concrete columns increased by 9.38%, while the compressive strength of concrete cylinders wrapped with 1, 2, 3-layer carbon fiber composite materials decreased by 12.10%, 10.81% and 13.88% respectively.