【作者】 徐静；

【导师】 李玉华；

【作者基本信息】 大连理工大学 ， 道路与铁道工程， 2013， 硕士

【摘要】 半刚性基层在我国的高速公路建设中得到广泛的应用,其中90%多都是半刚性基层沥青路面结构型式,成为我国主要的高速公路结构类型。半刚性基层有优越性,但同时也存在一定的缺陷,抗拉强度比较低,易开裂,因此半刚性基层的抗弯拉性能十分重要。本文以水泥稳定碎石为对象,通过室内劈裂强度试验和弯拉强度试验来研究其抗弯拉性能。劈裂强度试验分析了水泥剂量、养生龄期以及试件尺寸对劈裂强度的影响,结果表明：劈裂强度随水泥剂量、龄期的增长而增长,并通过圆柱体试件和立方体试件强度的对比预测劈裂强度存在尺寸效应。弯拉强度试验采用的是中梁试件100mm×100mm×400mm切割而成的非标准小梁试件40mm×40mm×200mm和中心加载模式,试验分析了弯拉强度随水泥剂量、养生龄期、养生温度变化的规律,结果表明：随着水泥剂量的增加、试验龄期的增长,弯拉强度呈增长趋势,低温养生不利于弯拉强度的形成,且此研究规律与采用标准弯拉试验研究的规律基本是一致的。同时,本文对劈裂强度和弯拉强度做了相关性分析,发现劈裂强度低于弯拉强度,二者的比值随养生龄期和水泥剂量增长变化不大,说明两种强度随龄期的增长速率相当,且受水泥剂量影响也基本相同。最后通过有限元建模计算,对劈裂强度、弯拉强度作了进一步分析。通过本文的试验研究,更好地认识水泥稳定碎石的抗弯拉性能,并提出了弯拉试验的新试验方法,为室内试验研究提供参考。更多还原

【Abstract】 Semi-rigid base has been widely used in China’s highway construction, of which more than90%are semi-rigid base asphalt pavement structure, to become China’s major highway structure. Semi-rigid base is superior, but there are some defects, for example, poor tensile strength, easy to crack, so the flexural tensile performance of the semi-rigid base is very important.In this paper, the splitting strength test and flexural tensile strength test are used to predict the flexural tensile performance of cement stabilized macadam. The influence of cement dosage, curing age and specimen size on splitting strength are analyzed by splitting strength test, which show that the splitting strength increase with the growth of cement dosage and curing age and that splitting strength size effect exists by the contrast of the strength of cylinder specimen and cube specimen. The non-standard beam specimens40x40x200mm, which are cut from beam specimens100x100x400mm, are used in the flexural tensile test. The loading mode in the test is center loading mode. The test analyzes the variation of flexural tensile strength with cement dosage, curing age as well as curing temperature. The test results show that flexural tensile strength of cement stabilized macadam present growth trend with the increase of cement dosage and curing age and that lower temperature isn’t benefit to the formation of flexural tensile strength. And the laws are consistent with the laws of standard flexural tensile strength. In addition, the correlation of splitting strength and flexural tensile strength are studied, which discover that splitting strength is lower than the flexural tensile strength and that the ratio don’t have significant change with the variation of cement dosage and curing age. The results illustrate that the growth rate of the strength with age is basically the same, and by the impact of cement dosage. Last, calculated by the finite element model, splitting strength, flexural strength and compressive strength was further analyzed.By the experimental study, a better understanding of the flexural tensile performance of cement stabilized macadam is acquired and a new test method of flexural tensile strength is put forward, which can provide a reference for laboratory test.更多还原