基于孔结构分析的多尺度聚丙烯纤维混凝土耐久性

Durability of Multi-dimensional Polypropylene Fiber Reinforced Concrete Based on Pore Structure Analysis

为研究不同尺度纤维对混凝土耐久性的影响,借助压汞法技术测定多尺度聚丙烯纤维混凝土内部孔隙的孔径大小及分布情况,通过孔径分布、最可几孔径、平均孔径等孔隙特征参数的变化情况,探究多尺度聚丙烯纤维在抗渗试验、抗硫酸盐侵蚀循环试验、抗冻融试验中对混凝土耐久性的影响。研究结果表明:不同尺度聚丙烯纤维的掺入,均使得混凝土内部多害孔和有害孔含量明显减少,少害孔与无害孔的含量大幅增加;混掺纤维的掺入可以进一步减小最可几孔径及平均孔径大小,缓解混凝土在耐久性试验中的劣化进程。

For further research on the influence of different scale fibers on the durability of concrete,the pore size and distribution of multi-scale polypropylene fiber concrete were measured by mercury intrusion method.According to the variation of pore characteristic parameters such as pore size distribution,the most probable pore size and average pore size,the effects of multi-scale polypropylene fiber on the durability of concrete in the impermeability test,sulfate resistance dry wet cycle test and freeze-thaw resistance test were evaluated.The investigation results show that the internal pore diameter of concrete can be refined by adding polypropylene fiber of different sizes,and greatly increase the content of less harmful and harmless holes.The addition of mixed fiber can further reduce the maximum and average pore size,thus alleviating the deterioration process of concrete in durability test.