侵蚀环境下高性能FRP筋材力学性能退化实验研究与分析

发布时间：2018-01-22 04:00

本文关键词： FRP筋恶劣侵蚀环境拉伸性能评价模型　出处：《江苏大学》2017年硕士论文　论文类型：学位论文

【摘要】：纤维复合增强筋(Fiber Reinforced Polymer Rebar)是有效提升普通混凝土结构耐久性能的新途径之一,它具备普通钢筋所不具备的比重小、比强高、抗侵蚀等优势,相比普通钢筋具有极大的发展潜力。迄今为止,大多数研究的是FRP筋材在加速侵蚀环境下的力学性能,并不能将研究成果直接与实际工程应用相结合,具有一定的局限性。本文通过FRP筋的自然老化试验,对CFRP(Carbon Fiber Reinforced Plastic)筋和GFRP(Glass Fiber Reinforced Plastic)筋材的耐久性能进行了持续观测和试验研究,主要包括以下几方面的研究工作:1、对恶劣侵蚀环境下的玻璃纤维筋材和碳纤维筋材进行了力学性能实验和研究,测定并分析了测试筋材的弹模、极限强度、破坏模式等。试验结果表明:FRP筋的破坏模式与尺度相关,对于同种玻璃纤维筋材,名义直径12mm相对于8mm的筋材,其拉伸破坏形态可近似看作炸散型;相比GFRP与CFRP筋,GFRP炸散形态更接近于炸散型。对比分析不同种FRP筋抗拉强度的极限,存在尺度效应,且随直径增加,极限强度有所降低;侵蚀试验后测试两种筋材的杨氏弹模,发现与厂家提供的理论范围(GFRP:40GPa~45GPa)、(CFRP:130GPa~140GPa)相吻合。2、探究了恶劣侵蚀环境(清水、碱溶液、人工海水溶液)对纤维筋抗腐蚀性能以及力学性能退化的机理。结果表明:对相同直径的GFRP筋抗拉性能在碱溶液状况中降低较明显,清水相对于盐溶液侵蚀,极限抗拉性能劣化不显著。3、探究恶劣侵蚀环境对纤维复合筋杨氏弹模的影响。结果表明当增加侵蚀浸泡时间时,FRP筋杨氏模量有一定程度的降低,且弹模劣化水平与初始物理力学性能相关,碳纤维复合筋材的拉应力最大值高于同直径的GFRP筋,且在恶劣侵蚀环境下力学性能降低较少。4、对已有碳纤维及玻璃纤维筋抗拉强度测试的相关数据进行可靠度分析和计算,并结合一次二阶矩的计算方法,对确定侵蚀环境下FRP筋力学性能所对应的可靠指标进行了探究,对FRP-混凝土全寿命周期设计给出一定参考与建议。
[Abstract]:Fiber Reinforced Polymer rebar is one of the new ways to improve the durability of ordinary concrete structures. It has the advantages of small proportion, high ratio, corrosion resistance and so on. It has great development potential compared with ordinary steel bar. So far. Most of the studies are on the mechanical properties of FRP bars under accelerated erosion environment, which can not be directly combined with the actual engineering applications. In this paper, the natural aging test of FRP tendons is carried out. For CFRP(Carbon Fiber Reinforced plastic tendons and GFRPs. The durability of Glass Fiber Reinforced plastic bar has been continuously observed and tested. This paper mainly includes the following research work: 1. The mechanical properties of glass fiber reinforced material and carbon fiber reinforced material under severe erosion environment are tested and studied. The elastic modulus and ultimate strength of the test steel bar are measured and analyzed. The test results show that the failure mode of the WFRP bars is related to the scale. For the same kind of fiberglass tendons, the nominal diameter of 12 mm is relative to that of 8 mm. The tensile failure morphology can be regarded as the explosive type. Compared with GFRP and CFRP, the morphology of GFRP is more similar to that of CFRP. The tensile strength limits of different FRP bars are compared and analyzed, and there is a scale effect, which increases with the diameter. The ultimate strength is decreased; After the erosion test, the Young's elastic modulus of the two kinds of tendons was tested, and the theoretical range provided by the manufacturer was found to be in the range of GFRP: 40GPa45GPa. CFRP: 130GPa140GPa) coincided with .2and explored the environment of severe erosion (clear water, alkaline solution). The mechanism of degradation of corrosion resistance and mechanical properties of fiber tendons in artificial sea aqueous solution. The results show that the tensile properties of GFRP tendons of the same diameter are obviously decreased in alkaline solution. Compared with salt solution erosion, the ultimate tensile performance of clear water is not significantly deteriorated. 3. The effects of severe erosion environment on Young's elastic modulus of fiber composite tendons are investigated. The results show that when the erosion immersion time is increased. The Young's modulus of FRP tendons is reduced to some extent, and the degradation level of elastic modulus is related to the initial physical and mechanical properties. The maximum tensile stress of CFRP composite tendons is higher than that of GFRP tendons of the same diameter. The mechanical properties of carbon fiber and glass fiber tendons are reduced less. 4. The reliability analysis and calculation of the existing data of tensile strength test of carbon fiber and glass fiber reinforcement are carried out and combined with the calculation method of first order second order moment. This paper probes into the reliable indexes corresponding to the mechanical properties of FRP tendons under erosion environment, and gives some references and suggestions for the design of the whole life cycle of FRP- concrete.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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