冻融条件下水泥稳定碎石力学性能变化规律试验研究

发布时间：2018-04-06 01:07

本文选题：水泥稳定碎石　切入点：抗压回弹模量　出处：《哈尔滨工业大学》2015年硕士论文

【摘要】：水泥稳定碎石基层由于具有较好的强度和耐久性、较高的承载能力和整体稳定性,目前在我国高速公路建设中应用广泛。在我国,90%以上的各等级公路基层采用石灰粉煤灰以及水泥稳定类等半刚性材料。但水泥稳定碎石基层也存在着一些缺点:比如对重载敏感性大、排水性能差、容易收缩开裂、表面容易冲刷等。北方季冻地区地区具有全年低温时间长、冬季漫长寒冷、寒暑变化剧烈、早晚温差大的气候特点。这样的气候环境影响水泥稳定碎石基层材料的路用性能。水泥稳定基层在初冬和春融期经常处于冻融循环状态。因此本文对该地区水泥稳定碎石基层在冻融循环作用下的力学性能进行了相关的试验分析研究。本文将参照相关试验规程进行室内试验,制备并养生试件,进行冻融循环,并测定材料在冻融循环之后的力学性能的变化情况,处理并分析得到的试验数据,研究力学性能变化规律,进而研究力学性能变化对路面结构的影响,具体的工作包括以下几点:冻融作用下水泥稳定碎石力学性能变化规律。从确定水泥稳定碎石原材料的技术性质入手,确定试验条件下的最佳含水量和最大干密度,并以此为依据通过试验确定水泥剂量。制备并养生圆柱式试件,进行冻融循环试验。以顶面法确定材料的抗压回弹模量并进行劈裂试验,并对试验结果进行分析处理,找出其变化规律。冻融循环对水泥稳定碎石疲劳性能的影响。制备并养生水泥稳定碎石材料中梁式试件,进行冻融循环试验。到规定的冻融次数后,测定材料的弯拉强度,在此基础上进行材料的疲劳试验。分析并处理得到的实验数据,总结水泥稳定碎石材料在不同冻融循环次数下疲劳寿命的变化情况,得到不同保证率下的疲劳方程。冻融循环对水泥稳定碎石基层路面结构的影响。基于前面得到的水泥稳定碎石基层在不同冻融循环次数作用下的抗压回弹模量以及劈裂强度,借助路面结构分析软件处理相关数据,研究力学性能变化对路面各结构层层底拉应力以及弯沉的影响,进而分析对整个路面结构所带来的影响。
[Abstract]:Cement stabilized crushed stone base is widely used in highway construction in China because of its good strength and durability, high bearing capacity and overall stability.Lime fly ash and cement stabilizer are used as semi-rigid materials in more than 90% of highway bases in China.But there are some disadvantages in cement stabilized macadam base, such as high sensitivity to heavy load, poor drainage performance, easy shrinkage and cracking, easy surface erosion and so on.The seasonal freezing area in northern China is characterized by long low temperature, long and cold winter, sharp changes in cold and summer heat, and large temperature difference in the morning and evening.This climate affects the road performance of cement-stabilized macadam base material.Cement stabilized base is often in the state of freeze-thaw cycle in early winter and spring thawing period.In this paper, the mechanical properties of cement stabilized macadam base under freeze-thaw cycle are studied.In this paper, laboratory tests will be carried out according to the relevant test procedures. The samples will be prepared and preserved, and the freeze-thaw cycles will be carried out. The mechanical properties of the materials after freeze-thaw cycles will be measured, and the experimental data obtained will be processed and analyzed.The change law of mechanical properties and the influence of mechanical properties on pavement structure are studied. The specific work includes the following points: the change law of mechanical properties of cement stabilized macadam under freeze-thaw action.Based on the determination of the technical properties of the raw materials of cement stabilized crushed stone, the optimum moisture content and the maximum dry density under the test conditions are determined, and the cement dosage is determined on the basis of the tests.The cylindrical specimen was prepared and kept in good health, and the freeze-thaw cycle test was carried out.The elastic modulus of the material was determined by the top surface method, and the splitting test was carried out. The experimental results were analyzed and treated to find out the variation law.Effect of freeze-thaw cycle on fatigue performance of cement stabilized crushed stone.The beam specimen of cement stabilized macadam was prepared and tested by freeze-thaw cycle test.After the specified freeze-thaw times, the flexural tensile strength of the material was measured, and the fatigue test of the material was carried out on this basis.By analyzing and processing the experimental data, the changes of fatigue life of cement stabilized macadam under different freeze-thaw cycles are summarized, and the fatigue equations under different guarantee rates are obtained.The influence of freeze-thaw cycle on pavement structure of cement stabilized crushed stone base course.Based on the modulus of resilience and splitting strength of cement stabilized macadam base under different freeze-thaw cycles, the pavement structure analysis software is used to process the relevant data.The influence of mechanical properties on the tensile stress and deflection of each layer of pavement structure is studied, and the influence on the whole pavement structure is analyzed.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414

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