聚丙烯纤维粉煤灰混凝土抗硫酸盐侵蚀性能试验研究

发布时间：2019-03-12 20:45

【摘要】：硫酸盐侵蚀降低混凝土强度,容易造成混凝土结构失效。在混凝土中掺加适量的粉煤灰可以减少水泥用量,增强混凝土的力学性能,提高混凝土的抗硫酸盐侵蚀性能。试验研究了聚丙烯纤维掺量为1kg/m3情况下,粉煤灰掺量分别为0、15%、30%,侵蚀状态分别为自然浸泡和干湿循环浸泡,硫酸盐侵蚀时间分别为1个月、2个月、3个月、4个月、5个月的聚丙烯纤维混凝土基本力学性能以及硫酸盐侵蚀时间分别为1d、14d、28d时的质量损失和强度损失。不同侵蚀状态下基本力学性能试验结果表明,硫酸盐侵蚀聚丙烯纤维混凝土的强度总体呈下降趋势。粉煤灰掺量为15%时,在硫酸盐自然浸泡侵蚀状态下,侵蚀了1个月、2个月、3个月、4个月、5个月的聚丙烯纤维混凝土强度相比于未掺加粉煤灰的混凝土强度分别降低了 2.3%、3.2%、19.4%、13.8%、25.6%;干湿循环侵蚀状态下,相比于未掺加粉煤灰混凝土试件分别降低了-6.91%、1.50%、2.40%、5.26%、6.01%。试验结果同时表明,当粉煤灰掺量为15%时,混凝土强度最大,即抗硫酸盐侵蚀性能最佳。质量损失和强度损失试验结果表明,硫酸盐侵蚀聚丙烯纤维混凝土试件的质量和拉压强度呈下降趋势,混凝土试件受侵蚀后的整体质量逐渐减少,强度下降,耐久性能降低。粉煤灰掺量为15%时,硫酸盐侵蚀聚丙烯纤维混凝土试件在1d、14d、28d 时的质量分别为 2.8655kg、2.38275kg、2.37950kg,抗压强度为 60.3MPa、55.7MPa、55.4MPa,劈裂抗拉强度分别为 4.27MPa、3.94MPa、3.83MPa,相比于粉煤灰掺量为0和30%的混凝上试件强度更大。混凝土结构内部掺加粉煤灰不仅提高试件强度,抗硫酸盐侵蚀性能也会得到提升并能满足其耐久性,节能环保,为王程应用提供试验数据。
[Abstract]:Sulfate erosion reduces the strength of concrete, and it is easy to cause failure of concrete structure. Adding a proper amount of fly ash into concrete can reduce the amount of cement, enhance the mechanical properties of concrete, and improve the resistance to sulfate erosion of concrete. When the content of polypropylene fiber is 1kg/m3, the content of fly ash is 0, 15%, 30%, the erosion state is natural immersion and dry-wet cycle immersion, and the sulfate erosion time is 1 month, 2 months, 3 months, respectively, and the amount of fly ash is 0%, 15%, 30%, the erosion state is 1 month, 2 months, 3 months, respectively. The basic mechanical properties and sulfate corrosion time of polypropylene fiber reinforced concrete for 4 months and 5 months were 1 d, 14 d, 28 d, respectively, and the mass loss and strength loss were obtained at 1 d, 14 d and 28 d, respectively. The experimental results of basic mechanical properties under different erosion conditions show that the strength of sulfate-eroded polypropylene fiber concrete is generally decreasing. When the content of fly ash was 15%, it was corroded for 1 month, 2 months, 3 months, 4 months under the condition of natural sulfate immersion. Compared with the concrete without fly ash, the strength of polypropylene fiber concrete decreased 2.3%, 3.2%, 19.4%, 13.8%, 25.6% respectively. Under the condition of dry and wet cycle erosion, the concrete specimens without fly ash decreased by-6.91%, 1.50%, 2.40%, 5.26% and 6.01%, respectively. The test results also show that when the content of fly ash is 15%, the strength of concrete is the highest, that is, the resistance to sulfate erosion is the best. The results of mass loss and strength loss test show that the mass and tensile strength of sulfate-eroded polypropylene fiber concrete are decreasing, and the whole mass and strength of concrete are decreased gradually, and the durability of concrete is decreased after being corroded. When the content of fly ash is 15%, the mass of sulfate-eroded polypropylene fiber concrete is 2.8655kg, 2.38275kg, 2.37950kg, compressive strength 60.3MPa, 55.7MPa, 55.4MPa respectively at 1 d, 14 d, and 28 d, respectively, when the content of fly ash is 15%, the mass of the specimens is 2.8655kg, 2.38275kg, 2.37950kg, respectively. The splitting tensile strength is 4.27 MPA, 3.94 MPA and 3.83 MPA, respectively, which is higher than that on the coagulation specimen with 0 and 30% fly ash content. The addition of fly ash in the concrete structure can not only improve the strength of the specimen, but also improve the resistance to sulfate erosion and meet its durability, energy saving and environmental protection, thus providing experimental data for Wang Cheng's application.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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