预应力混凝土用钢绞线弹性模量不确定度来源分析及评定

Analysis and evaluation of elastic modulus uncertainty source of steel strands for prestressed concrete

为满足预应力混凝土用钢绞线在重要工程建设中的使用要求,《预应力混凝土用钢绞线》对钢绞线的弹性模量规定(195±10) GPa,预应力混凝土用钢绞线施工时,要求实际伸长值与理论伸长值误差不超过6%。准确测定弹性模量及不确定度评定对钢绞线产品质量把控和钢绞线伸长量计算具有重要意义。采用拉伸试验测定钢绞线弹性模量,对钢绞线弹性模量不确定度来源进行分析,通过对钢绞线弹性模量的测量及对误差等进行计算,得出在kp=2及95%的置信水平下,弹性模量的试验结果准确表示为(199±10) GPa,对弹性模量不确定度进行评定可为把控评价钢绞线弹性模量质量和预应力施工伸长量计算提供参考。

To meet requirements for use of prestressed concrete steel strands in important engineering construction,Steel strands for prestressed concrete specifies elastic modulus of steel strands(195±10)GPa.When constructing steel strands for prestressed concrete,it is required that error between actual elongation value and theoretical elongation value should not exceed 6%.Accurate measurement of elastic modulus and uncertainty evaluation has great significance for controlling steel strand products quality and calculating steel strand elongation.Using tensile testing to determine steel strands elastic modulus and analyzing uncertainty sources of steel strands elastic modulus.By measuring steel strands elastic modulus,calculating repeated measurement errors of elastic modulus.At a confidence level of k p=2 and 95%,the experimental results of elastic modulus are accurately expressed as(199±10)GPa,and uncertainty of elastic modulus is evaluated,which can provide reference for controlling and evaluating quality of steel strand elastic modulus and calculating elongation of prestressed construction.