混杂纤维混凝土的耐硫酸盐腐蚀性能研究

为了研究混杂纤维混凝土抗硫酸盐腐蚀性能,对聚乙烯纤维(PE)与聚丙烯粗合成纤维(HPP)混凝土进行硫酸盐干湿循环腐蚀和长期浸泡侵蚀试验,采用形貌损伤、质量损失、相对动弹性模量和抗压强度等宏观测试方法研究了混杂纤维混凝土耐硫酸盐腐蚀性能,并结合SEM微观结构测试技术分析了其腐蚀机理.结果表明:不同纤维掺量的混凝土在硫酸盐腐蚀作用下均出现了不同程度的损伤,其干湿循环的腐蚀作用较长期浸泡腐蚀混凝土的腐蚀损伤更为明显;长期浸泡腐蚀作用时,450 d素混凝土抗压强度可达到60 MPa,各纤维混凝土抗压强度均可达到70 MPa,但在干湿循环腐蚀作用下,聚乙烯纤维和聚丙烯粗合成纤维以0.8%+1.2%掺入时,混凝土抗压强度也可达到70 MPa;纤维对于混凝土内部结构应力的缓解,孔隙、通道等缺陷的分散以及纤维之间的捆绑桥联都显著的提高了混凝土抗硫酸盐腐蚀性.

Sulfate Corrosion Resistance of Hybrid Fiber Reinforced Concrete

In order to further improve the resistance of concrete to sulfate corrosion, under the condition of optimum mix proportion, the experiment of dry and wet corrosion and long-term immersion corrosion of concrete with different fiber content was carried out.The macro test methods such as morphology damage observation, mass loss, relative dynamic elastic modulus and compressive strength were adopted, to study the corrosion resistance of hybrid fiber concrete and its corrosion mechanism by SEM microstructure test.The results show that the concrete with different fiber content has different degree of damage under sulfate corrosion;the corrosion damage under the wet and dry cycle is more obvious than the long-term soaking corrosion.In the long-term immersion corrosion time of 450 d, the concrete has a compressive strength of 60 MPa, and the fiber concrete has a compressive strength of 70 MPa.However, in the dry and wet cycle corrosion, polyethylene fiber and polypropylene crude synthetic fiber mixed with 0.8%+1.2%, the concrete also has a compressive strength of 70 MPa.Fiber can alleviate the internal structural stress of concrete, disperse porosity, channel and other defects, as well as fiber bundles between the bridge are significantly improved the resistance to sulfate corrosion of concrete.