大流动度路面混凝土力学性能试验研究

发布时间：2018-06-13 04:02

本文选题：大流动度路面混凝土 + 正交试验　；参考：《重庆交通大学》2015年硕士论文

【摘要】：大流动度混凝土是指坍落度不小于160mm,工作性好,坍落度经时损失小的一种高性能混凝土。大流动度混凝土具有良好的工作性、优异的力学性能、耐久性,在我国建设工程领域得到了广泛的应用。将大流动度混凝土应用于路面工程不仅施工速度快,而且可以减少环境污染和噪音喧哗,有着显著的社会、经济效益。目前我国大流动度路面混凝土的研究相对较少,缺乏完善的技术和规程,而且大流动度路面混凝土的力学性能研究也很分散。因此,研究大流动度路面混凝土的力学性能对提高市政道路路面建设质量具有重要意义。本文首先对大流动度路面混凝土的原材料进行研究,提出了各种原材料的技术要求;接着对大流动度路面混凝土进行配合比设计,采用正交试验设计方法,选定水胶比、胶凝材料用量、砂率、粉煤灰掺量四个因素进行试验,以坍落度值和7d、28d龄期下的抗压强度、抗折强度作为评价指标,利用极差、方差分析方法分析了各因素对坍落度、强度影响程度的大小,并根据各因素的影响程度进行配合比调整。在正交试验设计的基础上,研究不同因素变化对大流动度路面混凝土抗压、劈裂、抗折、抗冲击、弹性模量等力学性能及早期抗裂性能的影响,同时利用MIDAS有限元软件对大流动度路面混凝土力学性能进行数值模拟分析,研究了大流动度路面混凝土在不同受力作用下的应力分布和破坏机理,并对计算值和实测值进行比较以验证试验的准确性。最后利用SEM图片对大流动度路面混凝土的粉煤灰-水泥硬化浆体的微观结构进行观察和分析,研究发现适量的粉煤灰有助于提高大流动度路面混凝土的力学性能,最佳掺量为20%。
[Abstract]:Large fluidity concrete is a kind of high performance concrete with good workability and low slump loss. Because of its good workability, excellent mechanical properties and durability, high fluidity concrete has been widely used in the field of construction engineering in China. The application of large fluidity concrete to pavement engineering not only has a fast construction speed, but also can reduce environmental pollution and noise. It has remarkable social and economic benefits. At present, the research of high flow pavement concrete in our country is relatively few, lack of perfect technology and regulation, and the study of mechanical performance of high flow pavement concrete is also very scattered. Therefore, it is of great significance to study the mechanical properties of high flow pavement concrete to improve the construction quality of municipal road pavement. In this paper, the raw materials of high flow pavement concrete are studied firstly, and the technical requirements of various raw materials are put forward, then the mix ratio of high flow pavement concrete is designed, and the water binder ratio is selected by orthogonal design method. Four factors, the amount of cementing material, sand rate and fly ash content, were tested. The slump value and the compressive strength and flexural strength of the cement under the age of 7 days and 28 days were taken as the evaluation indexes. The slump was analyzed by using the method of extreme difference and variance analysis. The intensity influence degree, and according to each factor influence degree carries on the mix proportion adjustment. On the basis of orthogonal experimental design, the effects of different factors on the compressive, split, flexural, impact and elastic modulus of high fluidity pavement concrete are studied. At the same time, by using Midas finite element software, the mechanical properties of pavement concrete with large fluidity are simulated and analyzed, and the stress distribution and failure mechanism of pavement concrete with large fluidity under different forces are studied. The accuracy of the test is verified by comparing the calculated values with the measured values. Finally, the microstructure of fly ash cement hardened paste of high flow pavement concrete is observed and analyzed by SEM image. It is found that proper amount of fly ash is helpful to improve the mechanical properties of high flow pavement concrete, and the best content is 20%.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414

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