刚性路面沥青夹层早龄期-服役期影响机制研究

发布时间：2018-05-23 13:11

本文选题：刚性路面板 + 沥青功能夹层　；参考：《福州大学》2014年硕士论文

【摘要】：刚性路面在重载交通作用下经常出现过早断板现象,近年来业界提出在面板与基层之间设置沥青功能夹层,改善刚性路面的力学性能,但目前相关理论研究落后于工程实践。特别是,近年来早龄期理论分析显示界面的影响十分复杂。鉴于此,本文拟通过数值分析,现场足尺板试验的方法,重点对沥青功能夹层的早龄期-服役期工作影响机制开展研究。具体包括沥青夹层路面板早龄期力学行为、参数敏感性,夹层参数影响机制,以及考虑车辆荷载作用下沥青夹层路面板早龄期-服役期工作机制。具体研究结论如下：沥青夹层路面板在前72h翘曲变形主要以板角翘曲为主,72h后随着弹性模量的增长1/4路面板、板中处才参与翘曲变形,并出现板中脱空现象。早龄期应力随龄期增长而增长,且板角处及板中处应力变化规律不一致,板角处顶部和底部同时表现受拉或者受压,而板中处顶部和底部早龄期应力出现拉压反向的特点。与普通板相比,设置沥青夹层后板角处翘曲位移显著减小,但是板中的翘曲量则明显增大。同时,沥青夹层设置会显著减小路面板早龄期拉应力,而板底剪应力主要受到板中翘曲影响,板中翘曲量越大,板底剪应力越大。对早龄期路面板的翘曲和应力的参数敏感性分析表明,弹性模量、热膨胀系数、泊松比、徐变柔度参数等材料参数影响显著,夹层界面切向刚度影响则居其次,夹层厚度和模量的影响较弱。夹层界面切向刚度的增大会明显增加路面板早龄期板角翘曲,却又显著降低板中翘曲量。夹层厚度和模量增加对路面板早龄期拉应力影响不大,但会显著减小板底剪应力和早期界面开裂风险。四个季节下设置沥青夹层后板角翘曲及板底拉应力均降低,春秋冬季板中位移变化不大。而夏季早期施工设置夹层后板中在较早龄期便开始出现拱起现象,且拱起量明显大于未设夹层板,夏季板底拉应力下降最明显。与未设夹层结构相比,车辆荷载和早龄期性状耦合作用下,设沥青夹层结构受荷性能明显更加不利。对耦合应力影响显著的早龄期性状参数主要是翘曲形状和翘曲量,早龄期应力影响则很小。粗糙界面对于早期板角翘曲形成不利,但在服役阶段对于抵抗重载引起的应力有力。最后,通过足尺板试验发现设置沥青夹层后,路面板板中区域容易拱起,而板边更容易下压；另外,设置沥青功能夹层后路面板的早龄期应力较低,维持在0.5～1.4MPa之间。有限元计算结果与试验结果显示,早龄期路面板力学行为影响因素十分复杂,徐变、收缩、损伤、界面的龄期变化都需要进一步研究考虑。
[Abstract]:Rigid pavement often appears premature breakage under the action of heavy load traffic. In recent years, the industry has proposed to set up asphalt functional sandwich between the face slab and the base to improve the mechanical performance of the rigid pavement, but the relevant theory research lags behind the engineering practice at present. In particular, the influence of interface on early age analysis is very complicated in recent years. In view of this, through numerical analysis and the method of field full-scale plate test, the influence mechanism of asphalt functional sandwich from early age to service period is studied in this paper. It includes the mechanical behavior, parameter sensitivity, the influence mechanism of interlayer parameters, and the working mechanism of asphalt sandwich pavement panel under vehicle load. The concrete research results are as follows: the main warpage deformation of asphalt sandwich pavement is the angular warping of the slab 72 hours after the increase of elastic modulus 1 / 4 road panel, the central part of the board only participate in the warpage deformation, and appear the phenomenon of void in the plate. The stress of early age increases with the increase of age, and the stress changes at the corner and in the plate are not consistent. The top and bottom of the plate show tensile or compression at the same time, while the stress at the top and bottom of the plate show the characteristics of reverse tension and compression. Compared with the ordinary plate, the warpage displacement at the corner of the plate is significantly reduced, but the amount of warpage in the plate increases obviously. At the same time, asphalt intercalation can significantly reduce the early age tensile stress, and the shear stress is mainly affected by the warpage in the plate. The larger the warpage in the plate, the greater the bottom shear stress. The parameter sensitivity analysis of warpage and stress of early age pavement panel shows that elastic modulus, coefficient of thermal expansion, Poisson's ratio and Xu's flexibility have significant influence on material parameters, and the influence of interlayer tangential stiffness is the second. The influence of interlayer thickness and modulus is weak. The increase of the tangential stiffness of the interlayer interface will obviously increase the angular warpage of the early age panel, but decrease the amount of warpage in the plate. The increase of interlayer thickness and modulus has little effect on the tensile stress at early age, but it can significantly reduce the shear stress and the risk of early interface cracking. The angle warpage and the tensile stress of the slab bottom decreased after the asphalt sandwich was installed in the four seasons, but the displacement of the plate in spring and autumn did not change much. However, in the early summer construction, the arch rise began to appear in the early stage of construction, and the arch rise was obviously larger than that without the sandwich plate, and the tensile stress of the bottom of the plate decreased most obviously in summer. Compared with the structure without interlayer, the loading performance of asphalt sandwich structure is more unfavorable under the coupling of vehicle load and early age behavior. The significant effect on coupling stress in early age is the warpage shape and warpage quantity, but the early age stress has little effect on it. The rough interface is unfavorable to the early warpage of the plate, but it has the force to resist the stress caused by the heavy load during the service stage. Finally, through full-scale plate test, it is found that the area in the road panel is easy to arch and the edge is easier to be pressed after the asphalt sandwich is installed, and the early age stress of the rear road panel with the asphalt functional sandwich is lower, which is maintained between 0.5~1.4MPa. The results of finite element analysis and test show that the factors affecting the mechanical behavior of the early age road panel are very complex, and the creep, shrinkage, damage and the age change of the interface need to be further studied.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.2

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