Study on Durability Design and Construction Standard of Reinforced Concrete Construction

本课题的主要研究成果如下：1.采用流变学方法，通过压实模拟，掌握墙体模板中混凝土的活性; 2.对混凝土碳化退化因素进行了分类，并对混凝土碳化进行了预测分析。3.为了定量地研究温度对混凝土裂缝的影响，对高温气候条件下环境因素的影响进行了研究。外部因素（大气温度等）和内部因素（配合比设计、水泥种类等）4.为了量化环境因素对混凝土纤维降解的影响，评价混凝土纤维的耐久性，参照ASTM C-666 A中混凝土的循环次数，可以预测钢筋混凝土的使用寿命。5.通过断裂力学试验，对钢筋锈蚀引起的混凝土裂缝扩展进行了研究。裂缝宽度的变化可以用组合模型来描述。6.对钢筋混凝土在碳化或氯盐侵蚀下的腐蚀进行了试验研究，提出了用腐蚀率预测结构使用寿命的方法。7.从性能化标准的角度出发，提出了一种基于腐蚀率的结构使用寿命预测方法。并提出了一种利用硬化混凝土的化学成分、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.