天然轻骨料混凝土外掺粉煤灰力学性能及耐久性能试验研究

发布时间：2018-12-18 02:43

【摘要】：本文以天然浮石为粗骨料，利用工业废料粉煤灰，采用外掺法，配制了强度等级为LC50的天然轻骨料混凝土。针对不同掺量的粉煤灰，研究了天然轻骨料混凝土的基本力学性能和部分耐久性能。试验通过掺加0%、20%、30%和40%体积的粉煤灰替代相同体积的砂，配制了4组轻骨料混凝土，研究了3d、14d、21d、28d、60d和90d的抗压强度与28d的轴心抗压强度和弹性模量；研究了25次、50次、75次、100次、125次、150次和200次盐溶液快速冻融的动弹性模量；研究了5次、15次、30次、45次、50次、55次和60次抗硫酸盐侵蚀的质量损失和抗压强度。本文通过以上试验，结合试验数据，对抗压强度与龄期的关系、抗压强度与粉煤灰掺量的关系进行了分析，选出了抗压强度最优组；对快速冻融循环试验盐溶液试验组与清水对比组的相对动弹性模量进行了分析，探讨了盐冻耦合环境下轻骨料混凝土破坏机理；对在硫酸盐侵蚀环境下抗压强度与干湿循环次数关系、干湿循环相对质量损失进行了分析，建立了应力-应变曲线，研究了硫酸盐侵蚀对轻骨料混凝土的影响，探讨了粉煤灰在混凝土中抗硫酸盐侵蚀的作用机理。同时，，利用SEM电镜试验，对部分试验进行了微观分析。通过试验研究，得出了较为满意的试验结果，为今后天然轻骨料混凝土的发展提供试验依据。
[Abstract]:Using natural pumice as coarse aggregate and industrial waste fly ash, the natural lightweight aggregate concrete with LC50 strength grade was prepared by the method of admixture. The basic mechanical properties and partial durability of natural lightweight aggregate concrete were studied. In this experiment, four groups of lightweight aggregate concrete were prepared by adding 30% and 40% fly ash of 30% and 40% volume instead of the same volume of sand. The compressive strength of 60 d and 90 d and the axial compressive strength and elastic modulus of 28 d; The dynamic elastic modulus of 25 times, 50 times, 75 times, 100 times, 125 times, 150 times and 200 times of freezing and thawing of salt solution was studied, and the mass loss and compressive strength of 5 times, 15 times, 30 times, 45 times, 50 times, 55 times and 60 times of sulfate corrosion resistance were studied. In this paper, the relationship between compressive strength and age, the relationship between compressive strength and the content of fly ash is analyzed, and the optimum group of compressive strength is selected. The relative dynamic elastic modulus of salt solution test group and clear water contrast group were analyzed, and the failure mechanism of lightweight aggregate concrete under salt-freezing coupling environment was discussed. The relationship between compressive strength and the times of dry and wet cycles, the relative mass loss of dry and wet cycles, the stress-strain curve and the influence of sulfate erosion on lightweight aggregate concrete were analyzed. The mechanism of sulfate resistance of fly ash in concrete is discussed. At the same time, the microscopic analysis of some tests was carried out by means of SEM electron microscope test. Through experimental study, satisfactory test results are obtained, which provide experimental basis for the development of natural lightweight aggregate concrete in the future.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU528.2

【参考文献】