Study on Durability Design and Construction Standard of Reinforced Concrete Construction

本项目总结如下：用流变学方法，通过压实模拟，可以掌握墙体形式下混凝土的活动性。对混凝土碳化的影响因素进行了分类，并对混凝土碳化进行了预测分析。环境气候因子不仅存在于宏观层面，而且存在于中观和微观层面。为了量化温度对混凝土裂缝的影响，研究了高温气候条件下环境因素对混凝土裂缝的影响。外部因素（大气温度等）和内部因素（配合比设计、水泥种类等）对混凝土温度和脱水的影响。为了量化影响絮凝降解的环境因素，评价混凝土的絮凝耐久性，参考ASTM C-666A，采用混凝土循环来预测钢筋混凝土的使用寿命。通过钢筋腐蚀引起混凝土裂缝扩展的断裂力学试验，可以推导出裂缝宽度变化的组合模型。结果表明，在各种条件下，配筋扩展与裂缝宽度之间呈线性关系。对钢筋混凝土的碳化腐蚀和氯化物腐蚀进行了试验研究，提出了用腐蚀比预测结构使用寿命的方法。从性能标准的角度，研究了耐久性设计的参考文献，提出了一种利用硬质混凝土的化学成分、微观结构等参数进行耐久性设计的新方法。

The summary of this project as follows1.With rheological approach, we can grasp the activity of concrete in the wall form, by using the compacting simulation.2.We did clasify the degradation factors and make predictive analysis of concrete carbonation. It might be considered that not only enviromental climatic factor at macro-level but also at meso-level and micro-level.3.To quantify the effect of temperature on the crack of concret, it is examined about the effect of enviromental factor in hot climate. External factor (temperature of atmospher e.t.c) and internal factor (mix design, kind of cement, e.t.c.) on the temperature and dehydration of concrete.4.To quantify the enviromental factors that influence on flost degradation and to evaluate flost durability of concrete, using the cycle of concrete refer to ASTM C-666A we can predict the service life of reinforced concrete.5.With fracture mechanical experiment on the crack propagation of concrete caused by the reinforcing bar due to corrosion, transformation of crack width can be followed by the combination model. It was found that the relation between the expansion of reinforcing and the crack width under various conditions is lenear relation.6.We had experimental study about corrosion in reinforced concrete due to carbonation or chloride attack and proceeded a method for prediction of structure's service life using the corrosion ratio.7.From the stand point of performance-based standard, investigation references of Durability Design and suggest a new durability design method using the parameters of hardend concrete, for example, chemical component, microstructure, e.t.c.