C20混凝土组成材料与孔结构及性能关系的研究

该文通过压汞法、快速冻融法、美国电量法、干湿循环腐蚀法等试验分析了不同类型C20混凝土孔结构与性能的关系。对于C20混凝土,掺入复合矿物外加剂可使混凝土孔隙率降低,少害孔增加,有害及多害孔减少,混凝土早期强度没有降低,后期强度有增大的趋势,对抗渗性、抗腐蚀性较为有利,但对抗冻性改善不明显;掺入引气剂增加了混凝土孔隙率及多害孔,混凝土强度有所降低,对混凝土抗冻性、抗渗性、抗腐蚀性均不利;同时掺这两种物质时,虽增加了混凝土孔隙率,但可以使混凝土的孔径分布相对合理(多害及有害孔减少,无害及少害孔增大),混凝土强度降低不明显,对混凝土抗冻性、抗渗性、抗腐蚀性均有利。

Research of Relationship between Pore-structure,Performance and Material Composed of C20 Concrete

The relationship between pore structure and performance of the different types of C20 concrete is analyzed by the experiments of mercury intrusion method,rapid frozen thaw method, American coulometric method and dry-wet cycling eroding method.When the compound mineral admixture is mixed,the porosity rate of C20 concrete can be decreased and the less-harm hole is increased, the harmful hole and the more-harmful hole are decreased.The early strength of concrete is not decreased.But the strength has the increasing trend in the late,which is more favorable for the impermeability and corrosion resistance.But the improvement of the freezing resistance is not obvious. The admixture of air entraining agent can increase the porosity and more-harmful hole,and the concrete strength will be decreased,which will be not favorable for the freezing resistance,the impermeability and the anti-corrosion of concrete.If these two substances are admixed at the same time, the concrete porosity is increased,and the pore size distribution of concrete can be reasonable(decreasing more-harmful hole and harmful hole,and increasing the no-harmful and less-harmful hole). The decrement of concrete strength id not obvious,but it is favorable for the freezing resistance,the impermeability and the anti-corrosion of concrete.