循环冻融干湿条件下路用建筑垃圾力学性能及冻融微观结构试验研究

发布时间：2018-03-21 23:19

本文选题：路基工程　切入点：建筑垃圾　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着城市化进程的加快,建筑垃圾的产量与日俱增,造成严重的环境污染。合理的利用建筑垃圾,将其用于公路路基中,不仅可以解决对环境的污染,还可以缓解路用材料匮乏的问题。我国对建筑垃圾的研究起步较晚,很多技术都不成熟,对建筑垃圾作为路基填料的研究较少,本文参考了已有的研究结果,初步摸索出一套室内试验研究方法,旨在通过室内试验了解建筑垃圾的抗干湿及抗冻融性能。本文依托西咸北环线高速公路工程,通过基本物理试验,研究了建筑垃圾的基本物理力学指标。同时对不同配合比的建筑垃圾试件进行抗冻、抗干湿试验,并分析了塑性应变、弹性模量在冻融及干湿条件下的变化规律。另外,通过自主发明的CT扫描模具专利,实现了对建筑垃圾试件的CT扫描,分析了在分层击实条件下微观孔隙率随高度的变化规律;材料配合比与孔隙率之间的关系以及不同层位处孔隙率随冻融次数的变化规律。并尝试通过微观孔隙率变化对建筑垃圾宏观力学现象进行解释。研究表明,干湿循环和冻融循环均会导致建筑垃圾试样累积塑性应变增大、弹性模量减小。10次冻融为建筑垃圾塑性应变及弹性模量变化的拐点,超过该值以后塑性应变及弹性模量变化速度明显加快;60次干湿循环亦为两指标变化的拐点,大于该值后,两指标变化速度显著减缓。冻融条件下,建筑垃圾弹性模量及累计塑性应变变化与微观孔隙变化具有相关性。孔隙率平均增加7%时,弹性模量减小约13%,累计塑性应变增大约20%;当孔隙率平均增加20%时,弹性模量减小约40%,累计塑性应变增大约50%。
[Abstract]:Along with the city to speed up the process, construction waste production grow with each passing day, causing serious environmental pollution. The utilization of construction waste, be used in highway roadbed, not only can solve the environmental pollution, can also relieve the road material shortage. The research of construction waste in China started late, many technologies are not mature, construction waste as roadbed research less, this reference to the existing research results, initially worked out a laboratory test method to anti wet understanding of construction waste through the indoor test and anti freeze thaw performance. This paper relies on the West Ham Nol expressway project, through the basic physical test, the basic physical and mechanical indexes study on construction waste. At the same time of different proportion of construction waste specimens of antifreeze, anti dry test, and plastic strain analysis, elastic modulus in freeze-thaw and dry Changes of wet conditions. In addition, the CT scan mold patent invented, the CT scan specimens of the construction waste, analyzes the compaction conditions in layered micro porosity with height variation; the relationship between material mix ratio and porosity and porosity in different layers varies with the number of freeze-thaw. And try to explain the changes of the construction waste through the micro porosity macro mechanical phenomenon. The research results show that the wet dry cycles and freeze-thaw cycles may result in construction waste sample cumulative plastic strain increases, the elastic modulus decreases.10 freeze-thaw for construction waste inflection point plastic strain and elastic modulus change, more than the value of plastic strain and elastic modulus change significantly faster; the 60 dry wet cycle is also two inflection point index changes, larger than the value after the change rate of two indicators significantly slow. Under the condition of freezing and thawing, construction The construction waste elastic modulus and accumulated plastic strain change and micro pore changes associated with porosity. An average increase of 7%, the elastic modulus decreases about 13%, the cumulative plastic strain increased by about 20%; when the porosity increased by 20% on average, the elastic modulus decreases about 40%, the cumulative plastic strain increased by about 50%.

【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414;X799.1

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