相对法评价涂层混凝土冻融损伤

利用相对法分别计算了环氧砂浆涂层、聚氨酯涂层和聚脲涂层的动弹性模量及涂层混凝土内部的逐层动弹性模量,分析了混凝土内部结构损伤层的损伤演变规律,同时辅以扫描电镜(SEM)与压汞试验结果对相对法所得结论进行了验证.结果表明:3种涂层的抗冻防护效果为环氧砂浆涂层>聚氨酯涂层>聚脲涂层;混凝土构件表层的动弹性模量最低,冻融侵蚀最严重,混凝土构件内层的动弹性模量最大,基本未受侵蚀,混凝土构件损伤层动弹性模量由表及里的呈现递增至平缓的变化趋势;混凝土损伤层动弹性模量降低是由于多害孔的比例增大而引起的.

Relative Method for Evaluating Freeze Thaw Damage of Coated Concrete

The dynamic elastic modulus of epoxy mortar coating, polyurethane coating, polyurea coating and concrete with coating were calculated by using the relative method. The damage evolution law of the damage layer and the internal structure of concrete was analyzed. The results of the relative method were verified by the scanning electron microscopy(SEM) and the mercury intrusion test. The results show that effectivness of the frost resistance of the three coatings is in the following order: epoxy mortar coating>polyurethane coating>polyurea coating; the dynamic elastic modulus of the surface layer of concrete members is the lowest, and the freeze thaw damage and erosion are the most serious; the dynamic elastic modulus of the inner layer of concrete members is the highest, which is basically not eroded; the dynamic elastic modulus of damaged layer of concrete members increases from surface to inside and then changes smoothly; the decrease of dynamic modulus of elasticity of concrete members are caused by the increase of the proportion of harmful holes.