混凝土氧气扩散系数试验研究

Experimental study on diffusion coefficient of oxygen in concrete

为了确定混凝土材料氧气扩散系数和混凝土水灰比、环境相对湿度及环境温度的关系,根据Fick扩散定律的基本原理,研制了混凝土氧气扩散系数测试装置.利用该装置,进行了上述3种因素对混凝土氧气扩散系数影响效果的正交试验研究.结果表明,环境相对湿度对混凝土氧气扩散系数影响最明显,混凝土水灰比次之,环境温度的影响最后.根据试验结果,利用SPSS统计分析软件得到了混凝土氧气扩散系数和混凝土水灰比、环境相对湿度和环境温度相互关系的预计模型,为钢筋锈蚀的定量评价中合理确定混凝土氧气扩散系数提供了科学依据.

To find the relationship between the oxygen diffusivity and the water-binder ratio of concrete, relative humidity and temperature, base on the Fick's first law an equipment is designed which can test the oxygen diffusivity in concrete. By using this equipment, experiments were conducted according to the principle of orthogonal experimental design. The results show that the relative humidity is the main factor that affects the oxygen diffusivity in concrete and the water-binder ratio of concrete follows it. Based on the experimental results, the prediction model between the oxygen diffusivity and the three factors is developed. The prediction model enables to provide a scientific basis for the evaluation of the reinforcement corrosion in concrete.