高速公路半刚性基层沥青路面水损坏机理与结构层疲劳特性分析
发布时间：2019-02-12 15:55
【摘要】：半刚性基层沥青路面是我国高速公路主要的路面结构形式,虽然我国对半刚性基层沥青路面做了较为深入的研究,但对半刚性基层的特点并未全面认识,直接导致以半刚性基层沥青路面为代表的高速公路的路面早期破坏问题凸显,在这种研究背景下,本论文针对半刚性基层沥青路面的病害问题展开研究。通过对津京冀高速公路沿线半刚性基层沥青路面的病害进行全面调查,依据现行相关规范,采用路面平整度、路面车辙检测方法和路面结构强度试验等方法对高速公路水损坏状态及原因进行分析；进而对半刚性基层沥青路面水损害原因进行了分析评价,结果显示,水损坏芯样的沥青混合料标准密度偏低,沥青路面的实际残留空隙率较大,极易发生渗水现象,是造成沥青路面水损害破坏的主要原因；沥青层底部的弯拉应变在荷载作用下首先发生弯拉开裂,并逐渐向上扩展,成为水破坏的根源：沥青混合料及水稳碎石混合料表面附着有较厚的泥层,在遇水后泥层软化,使得胶结料与石料之间逐渐丧失粘结而发生松散,导致沥青路面水破坏在形式上主要体现为坑槽、松散和唧浆；水损害从类型上分为自上而下的表面层水破坏和自下而上的整体结构水破坏,是由于沥青与集料粘附力遭到破坏而产生的破坏现象,它不仅会导致松路面表面损坏,还降低了路面耐久性而诱发其它病害,甚至会迅速导致路面结构的整体性破坏,危害性极大：最后研究了两种典型半刚性沥青路面结构疲劳裂缝的形成机理,进而根据典型沥青路面设计计算图式,揭示路面结构力学响应机制,结果显示,层问滑动状态下半刚性基层层底的拉应力较层间连续状态相同位置的拉应力有明显增大,表明厚度增加对于降低路面结构内部水平拉应力具有明显的效果。本论文研究提出了防止沥青路面早期破坏预防措施,具有重要的现实意义,可为类似工程借鉴。
[Abstract]:Semi-rigid base asphalt pavement is the main pavement structure form of expressway in China. Although our country has done more in-depth research on semi-rigid base asphalt pavement, it has not fully understood the characteristics of semi-rigid base course. The early failure problem of expressway pavement represented by semi-rigid base asphalt pavement is highlighted directly. In this research background, this paper focuses on the disease of semi-rigid base asphalt pavement. Through the comprehensive investigation on the diseases of asphalt pavement with semi-rigid base along the Beijing-Hebei Expressway, according to the current relevant codes, the pavement smoothness is adopted. Pavement rutting detection method and pavement structural strength test are used to analyze the water damage status and causes of expressway. Furthermore, the causes of water damage of asphalt pavement with semi-rigid base are analyzed and evaluated. The results show that the standard density of asphalt mixture with water damage core is on the low side, the actual residual void ratio of asphalt pavement is large, and the phenomenon of water seepage is easy to occur. It is the main cause of water damage of asphalt pavement. The flexural strain at the bottom of the asphalt layer first cracks under load, and gradually extends upward, which is the root of water failure: the surface of asphalt mixture and water-stabilized macadam mixture has a thick mud layer attached to it, and the mud layer softens when it comes to water. As a result, the bond between binder and stone is loosened gradually, which leads to the water damage of asphalt pavement mainly reflected in pothole, looseness and slurry. Water damage is classified into top-down surface layer water damage and bottom-up overall structural water damage, which is caused by the failure of asphalt and aggregate adhesion force, which will not only lead to surface damage of loose pavement. It also reduces the durability of pavement and induces other diseases, and even leads to the destruction of pavement structure as a whole, which is extremely harmful. Finally, the formation mechanism of fatigue cracks of two typical semi-rigid asphalt pavement structures is studied. Furthermore, according to the design and calculation scheme of typical asphalt pavement, the mechanical response mechanism of pavement structure is revealed. The results show that the tensile stress of the base of semi-rigid base under the sliding state is obviously increased than that of the same position in the continuous state of the layers. It shows that the increase of thickness has obvious effect on reducing the horizontal tensile stress of pavement structure. In this paper, preventive measures to prevent early damage of asphalt pavement are put forward, which have important practical significance and can be used for reference in similar projects.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.217;U418.6
，
本文编号：2420572
[Abstract]:Semi-rigid base asphalt pavement is the main pavement structure form of expressway in China. Although our country has done more in-depth research on semi-rigid base asphalt pavement, it has not fully understood the characteristics of semi-rigid base course. The early failure problem of expressway pavement represented by semi-rigid base asphalt pavement is highlighted directly. In this research background, this paper focuses on the disease of semi-rigid base asphalt pavement. Through the comprehensive investigation on the diseases of asphalt pavement with semi-rigid base along the Beijing-Hebei Expressway, according to the current relevant codes, the pavement smoothness is adopted. Pavement rutting detection method and pavement structural strength test are used to analyze the water damage status and causes of expressway. Furthermore, the causes of water damage of asphalt pavement with semi-rigid base are analyzed and evaluated. The results show that the standard density of asphalt mixture with water damage core is on the low side, the actual residual void ratio of asphalt pavement is large, and the phenomenon of water seepage is easy to occur. It is the main cause of water damage of asphalt pavement. The flexural strain at the bottom of the asphalt layer first cracks under load, and gradually extends upward, which is the root of water failure: the surface of asphalt mixture and water-stabilized macadam mixture has a thick mud layer attached to it, and the mud layer softens when it comes to water. As a result, the bond between binder and stone is loosened gradually, which leads to the water damage of asphalt pavement mainly reflected in pothole, looseness and slurry. Water damage is classified into top-down surface layer water damage and bottom-up overall structural water damage, which is caused by the failure of asphalt and aggregate adhesion force, which will not only lead to surface damage of loose pavement. It also reduces the durability of pavement and induces other diseases, and even leads to the destruction of pavement structure as a whole, which is extremely harmful. Finally, the formation mechanism of fatigue cracks of two typical semi-rigid asphalt pavement structures is studied. Furthermore, according to the design and calculation scheme of typical asphalt pavement, the mechanical response mechanism of pavement structure is revealed. The results show that the tensile stress of the base of semi-rigid base under the sliding state is obviously increased than that of the same position in the continuous state of the layers. It shows that the increase of thickness has obvious effect on reducing the horizontal tensile stress of pavement structure. In this paper, preventive measures to prevent early damage of asphalt pavement are put forward, which have important practical significance and can be used for reference in similar projects.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.217;U418.6
，
本文编号：2420572
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