路基不同细粒含量级配碎石掺水泥力学特性及耐久性研究

发布时间：2018-05-04 01:23

本文选题：级配碎石 + 掺水泥　；参考：《西南交通大学》2015年硕士论文

【摘要】：哈大高铁客运专线是处于东北严寒地区的无砟轨道,是国家“十一五”规划的重点工程,其所经地段广泛地分布着季节性冻土。因此,针对哈大线路基工程,如何减少其路基冻胀量至标准范围内,是哈大客运专线面临的一个重要难题。文献[2]已经得出了级配碎石掺入水泥能够减少哈大客运专线路基的冻胀量的结论,并得出了水泥的合理掺量在5%～7%。在前面“路基不同细粒含量级配碎石掺水泥冻胀特性研究”的基础上,本文对级配碎石掺水泥这种材料的力学特性、冻融循环后的强度损失以及弯拉疲劳性能进行了分析研究。分析了水泥含量、细粉含量、减水剂含量对级配碎石掺水泥的力学特性影响规律,强度随着龄期的增长规律,各强度之间的关系规律；分析了水泥含量、细粉含量对级配碎石掺水泥冻融循环后的力学性能的影响规律；分析了级配碎石掺水泥的弯拉疲劳方程。主要研究内容及试验结果如下：(1)对级配碎石掺水泥的力学特性研究,结果表明水泥和细粉均是影响级配碎石掺水泥强度的关键性因素,其强度随水泥用量增大而增大、随细粉含量增大而降低、减水剂掺入可适当减少用水量,提高强度。在级配碎石掺水泥的强度龄期方面：28d强度与7d强度符合相关系数较高的线性公式。在级配碎石掺水泥强度关系方面：其28d抗压强度与弯拉强度符合相关系数较高的幂指数公式；压折比k与抗压强度符合相关系数较高的线性公式；劈拉强度与抗压强度符合相关系数较高幂指数公式；弯拉强度与弯拉弹性模量符合相关系数较高的幂指数公式。(2)对级配碎石掺水泥的冻融循环力学特性研究,结果表明50次冻融循环后级配碎石掺水泥的质量损失率在1.5%～3%之间,小于5%。在冻融循环后的抗压强度损失方面：50次循环后的强度损失在10%-30%之间。水泥含量与细粉含量对级配碎石掺水泥强度损失的影响具有一定的波动性,但是仍具有一定的规律性。(3)对级配碎石掺水泥的弯拉疲劳性能研究,结果表明级配碎石掺水泥的弯拉疲劳寿命满足双参数Weibull分布,并通过数学模型结合试验数据建立了级配碎石掺水泥的弯拉疲劳试验方程。
[Abstract]:The high-speed passenger dedicated line of Harbin and Dalian is a ballastless track in the cold area of northeast China. It is the key project of the 11th Five-Year Plan of China, and its section is widely distributed with seasonal frozen soil. Therefore, how to reduce the frost heave to the standard range is an important problem faced by Ha-Da passenger dedicated Line. In reference [2], it has been concluded that graded crushed stone mixing with cement can reduce the frost heaving capacity of subgrade of Ha-Da passenger dedicated line, and that the reasonable cement content is 5% and 7%. On the basis of "study on Frost heaving characteristics of different Fine grained crushed Macadam admixed with cement in roadbed", the mechanical properties, strength loss and bending and tensile fatigue properties of graded crushed Macadam mixed with cement after freeze-thaw cycle are analyzed and studied in this paper. The effects of cement content, fine powder content and water reducing agent content on the mechanical properties of graded crushed stone cement are analyzed. The effect of fine powder content on the mechanical properties of graded macadam after freeze-thaw cycle was studied, and the flexural fatigue equation of graded macadam with cement was analyzed. The main contents and experimental results are as follows: (1) the mechanical properties of graded macadam mixed with cement are studied. The results show that both cement and fine powder are the key factors affecting the strength of graded macadam, and the strength increases with the increase of cement content. With the increase of fine powder content, the water consumption can be reduced and the strength can be increased. The ratio of 28d strength to 7d strength accords with the linear formula with high correlation coefficient in the strength age of graded macadam mixed with cement. In the relation of cement strength of graded crushed stone, 28d compressive strength and flexural strength accord with the power exponent formula with higher correlation coefficient, and the linear formula with high correlation coefficient between compression ratio k and compressive strength. Splitting tensile strength and compressive strength accord with higher power exponent formula, flexural tensile strength and flexural elastic modulus accord with power exponent formula with high correlation coefficient. The results show that the mass loss rate of graded crushed stone mixed with cement after 50 freeze-thaw cycles is between 1.5% and 3%, which is less than 5%. The loss of compressive strength after freezing and thawing cycles is between 10% and 30% after 50 cycles. The influence of cement content and fine powder content on the strength loss of graded macadam cement has certain fluctuation, but still has certain regularity. The results show that the flexural fatigue life of graded macadam cement meets the Weibull distribution of two parameters, and the flexural fatigue test equation of graded macadam cement is established by mathematical model combined with test data.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414

【引证文献】