氯盐侵蚀-外加电流下TRC抗拉限裂性能研究

Study on the Tensile and Crack Limiting Performance of TRC under Chloride Salt Corrosion and Impressed Current

摘要:

为提高氯盐侵蚀-外加电流下纤维编织网增强混凝土（TRC）的抗拉限裂性能，本文首先通过抗压和抗折试验研究了复掺碳纤维和石墨后TRC基体所用细粒混凝土的力学性能，后通过单轴拉伸试验研究了纤维编织网层数和试件厚度对TRC抗拉性能的影响。研究表明，复掺碳纤维和石墨可有效提高细粒混凝土的抗拉强度；增加纤维编织网层数显著提升TRC的抗拉性能并改善裂缝发展，而增大试件厚度对拉伸性能和裂缝形态影响不大；最后，对碳纤维束进行微观分析，发现未外加电流的碳纤维单丝表面仍光滑完整，而外加电流的碳纤维单丝出现断裂。

Abstract:

To improve the tensile and crack limiting performance of Textile Reinforced Concrete (TRC) under chloride salt corrosion and impressed current. In this paper, the mechanical properties of fine-grained concrete mixed with carbon fiber and graphite are studied by compressive and flexural tests, and the effects of textile layers and specimen thickness on the tensile properties of TRC are studied by uniaxial tensile tests. Research has shown that the addition of carbon fiber and graphite can effectively improve the tensile strength of fine-grained concrete; Increasing the number of textile layers can significantly enhance the uniaxial tensile performance of TRC and improve the crack propagation morphology of TRC, While increasing the thickness of specimen does not significantly improve the tensile properties of TRC, and has little effect on the crack propagation morphology; Finally, the microscopic analysis of carbon fiber bundles reveals that the surface of carbon fiber monofilaments applied current remains smooth and intact, whereas the carbon fiber bundle monofilaments applied current are subjected to fracture conditions.