中文摘要：

氯盐环境严重影响混凝土耐久性，但现行规范通常按照强度要求设计混凝土配合比。为此，研究建立了混凝土的氯离子扩散系数多因素模型，并按照预定的混凝土强度和耐久性要求开展配合比分析和设计。首先选择混凝土的氯离子扩散系数及其龄期衰减系数作为混凝土抗氯盐耐久性能指标参数，研究建立了混凝土耐久性指标参数的多因素计算模型。然后，根据预定的强度指标和耐久性能指标的取值，通过求解代数方程组得到混凝土水胶比和矿物掺合料掺量。进而，结合混凝土的工作性能要求，分析确定混凝土配合比设计主要参数的取值。最后，结合工程实例和正交试验方法开展混凝土配合比试验。研究表明，根据本文建立的混凝土配合比设计方法制备混凝土，能同时满足预定的混凝土强度和耐久性能指标的要求，有效克服了传统理论的缺陷。

英文摘要：

The mix proportion of concrete is usually determined by the requirement on the strength of concrete according to current specifications. In this study, a multi-factor model for chloride ion diffusion coefficient is developed, and in this model, the mix proportion of concrete was analyzed and designed to satisfy the requirement of specified strength and durability. Firstly, the chloride ion diffusion coefficient of concrete and the decay index of concrete age were used as the design indices of concrete mix proportion, based on which the multi-factor model was established. Secondly, the water/ binder ratio and the amount of mineral admixtures were determined by solving algebraic system of equations according to the requirement on the specified values of strength index and durability index of concrete in chloride environment. Furthermore, according to the requirements on workability of concrete, the values for the main design parameters affecting the mix proportion of concrete were determined. Finally, based on a practical project and using orthogonal experimental method, a series of experiments on mix proportion of concrete were carried out to examine the proposed method. Results show that with the proposed design method for mix proportion, the prepared concrete can meet the requirements on both strength and durability indices, and the proposed design method can effectively overcome the limitation of traditional methods.