聚乙烯醇纤维改性混凝土及其抗盐蚀性能研究

Study on polyvinyl alcohol fiber modified concrete and its salt corrosion resistance

为缓解环境侵蚀对混凝土性能的影响,采用聚乙烯醇(PVA)纤维改性高强度混凝土,并对其抗盐蚀性能进行研究。结果表明,随着盐蚀的进行,各试件抗压强度均先提高后降低,PVA纤维掺量为0.2%、0.3%时混凝土初始抗压强度分别为50.6、47.5 MPa,较基准组分别提高了11.9%、5.1%;盐蚀150 d时,PVA纤维掺量为0.2%的试件抗压强度最高,达到52.7 MPa,较基准组提高了25.8%;各试件的相对质量先减少后波动增加,其中,PVA纤维掺量为0.2%的试件最稳定;各试件的相对动弹性模量先大幅度增大后波动变化。PVA纤维的最佳体积掺量为0.2%,可提高混凝土的抗压强度、减少质量损失、增大动弹性模量,此时,混凝土的抗盐蚀性能最佳。

In order to alleviate the impact of environmental erosion on the properties of concrete,this experiment modified high-strength concrete with polyvinyl alcohol(PVA)fiber and studied its salt corrosion resistance.The test results show that with the progress of the salt corrosion test,the compressive strength of all specimens increases first and then decreases.Among them,the initial compressive strength of concrete with 0.2%and 0.3%PVA content is 50.6 MPa and 47.5 MPa,respectively,which is 11.9%and 5.1%higher than that of the benchmark specimen.The maximum compressive strength of the test specimen with 0.2%PVA content reaches 52.7 MPa,which is 25.8%higher than that of the benchmark test.The relative mass of each specimens first decreases and then fluctuates,and the 0.2%PVA specimen is the most stable.The relative dynamic elastic modulus of each specimen first increases significantly and then fluctuates up and down.The optimum volume content of polyvinyl alcohol fiber is 0.2%,which can improve the compressive strength of concrete,reduce mass loss and increase dynamic elastic modulus.At this time,the salt corrosion resistance of concrete material is the best.