首先，提出了一个基于变系数广义开尔文模型的混凝土徐变度 Dirichlet 级数表达式，并依据延迟范围理论建立了九参数徐变度公式; 然后，推导了松弛系数率的表达式，并在此基础上提出了计算松弛系数的率型迭加算法; 最后，基于试验数据将文中建议的徐变度表达式以及率型迭加算法与常用的徐变度公式以及计算松弛系数的迭加算法进行了比较。结果表明: 提出的徐变度表达式物理概念清晰且能避免负徐变; 九参数徐变度公式的拟合精度高于常用的八参数徐变度公式; 率型迭加算法避免了普通迭加算法的误差传递现象，大幅度提高了早龄期混凝土持载时间较长时的拟合精度．

In this paper,first,a Dirichlet series expression of concrete creep based on the generalized Kelvin mod-el with variable coefficients is suggested,and a creep expression with nine parameters is proposed based on the con-tinuous retardation spectrum.Then,an expression of relaxation coefficient rate is derived and a rate- type superposi-tion algorithm is further proposed to calculate the relaxation coefficient.Finally,by using some experimental data,the suggested creep expression and the rate- type superposition algorithm are respectively compared with the commonones.The results indicate that (1) the proposed creep expression possesses explicit physical meaning and helps toavoid negative creep; (2) the creep expression with nine parameters is of higher fitting precision,as compared withthe expression with eight parameters; and (3) the proposed rate- type superposition algorithm helps to avoid the er-ror propagation existing in the traditional superposition algorithm and greatly improves the fitting precision of theearly- age concrete at longer lag- time stage.