低温条件下SRⅡ型外加剂对混凝土力学与耐久性能的研究

发布时间：2018-01-13 06:28

本文关键词：低温条件下SRⅡ型外加剂对混凝土力学与耐久性能的研究　出处：《沈阳工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：全面探究混凝土抗冻耐久性指标的同时,新型无氯·无碱型混凝土防冻剂作为一种有效、经济、环保的抗冻手段对水泥基制品作用机理以及抗冻耐久性能的改善方面也应进行深入探究。对不同冻结条件下的混凝土试件进行抗压强度、孔隙率、透气性、回弹强度、表面含水率、碳化以及单边冻融循环实验(CIF)后的重量损失、弹性模量损失等试验,综合比较分析后的结果表明混凝土试件在负温下的养护温度越低,恢复标准养护温度后强度恢复越好;混凝土试件特伦托透气系数小于10×10~(-16)m~2且回弹强度比大于85%,可以作为混凝土抗冻耐久性指标。针对我国目前相对比较空白的新型无氯·无碱型混凝土防冻剂,对掺加不同掺量防冻剂的水泥砂浆试件在不同冻结、养护条件下的各项性能、冻融循环后的抗冻耐久性能展开深入研究;并借助X-Ray物质衍射分析对掺入无氯无碱型防冻剂的砂浆试件水化作用机理进行探讨。试验结果表明该种新型无氯·无碱型防冻剂对普通硅酸盐水泥的最优配比为4%;粒化高炉矿渣水泥的最优配比为5%。新型无氯无碱型防冻剂不但可以降低砂浆试件中液相冰点,保证砂浆内部孔隙组织的完整性,还可以促进水泥水化生成物进行二次水化,增加水泥基制品强度,显著改善水泥基抗冻耐久性能。
[Abstract]:At the same time, a new type of non-chlorine and alkali-free concrete antifreeze is an effective and economical one. The mechanism of action and the improvement of anti-freezing durability of cement based products should also be deeply explored. The compressive strength, porosity and permeability of concrete specimens under different freezing conditions should also be studied. Springback strength, surface moisture content, carbonization and one-sided freeze-thaw cycle test after CIF-weight loss, elastic modulus loss and so on. The results of comprehensive comparison and analysis show that the lower the curing temperature of concrete specimen at negative temperature, the better the strength recovery after restoring the standard curing temperature. The permeability coefficient of Trent to concrete specimen is less than 10 脳 10 ~ (-1) -16m ~ (2) and the rebound strength ratio is more than 85%. It can be used as the durability index of concrete. Aiming at the relatively blank new type of non-chlorine and alkaline-free concrete antifreeze agent in our country, the concrete mortar specimens with different amount of antifreeze agent are frozen in different amounts. The properties and durability of freeze-thaw cycle under curing condition are studied deeply. The hydration mechanism of mortar specimens mixed with chlorine-free alkali-free antifreeze was discussed by means of X-Ray material diffraction analysis. The test results show that the new type of non-chlorine and alkali-free antifreeze is the most effective for ordinary Portland cement. The optimum ratio is 4. The optimum ratio of granulated blast furnace slag cement is 5. The new non-chlorine-free alkali-free antifreeze can not only reduce the liquid phase freezing point in mortar specimen, but also ensure the integrity of internal pore structure of mortar. It can also promote the secondary hydration of cement hydration products, increase the strength of cement based products, and significantly improve the durability of cement based freezing resistance.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

【参考文献】