锈蚀钢纤维力学性能及极限拉伸荷载计算方法

Mechanical Properties and Calculation Method for Ultimate Tensile Load of Corroded Steel Fibres

采用干湿循环法将钢纤维进行加速锈蚀,在分析其表观锈蚀特征的基础上,通过轴向拉伸试验和有限元分析研究了锈蚀程度对其力学性能退化的影响.结果表明:干湿循环处理后钢纤维表面出现了较多的锈坑,截面损失和锈坑处应力集中使其力学性能退化,而应力集中程度又取决于锈坑深度、宽度和钢纤维直径.建立了考虑锈坑深度、宽度和钢纤维直径影响的锈蚀钢纤维极限拉伸荷载退化模型,经试验验证,该模型也适用于计算锈蚀钢筋的极限拉伸荷载.

Steel fibres were corroded by using the method of drying-wetting cycles.Based on the investigation of their surface characters and according to the results of uniaxial tension test and finite element analysis,the effect of corrosion degrees on the deterioration of mechanical properties of corroded steel fibres was studied.Results show that many corrosion pits appear on the surface of the steel fibres after drying-wetting cycles.The deterioration of mechanical properties of corroded steel fibres is due to section loss and stress concentration at these pits.Moreover,the degrees of stress concentration depend on the varying pit depth,pit width and diameter of steel fibre.Finally,the deterioration model of ultimate tensile load of corroded steel fibres,considering the effects of pit depth,pit width and diameter of steel fibre,is proposed and verified by test results.Also,the model can be adopted for calculating the ultimate tensile load of corroded steel bars.