【作者】 杨晓东；

【导师】 郭成超；

【作者基本信息】 郑州大学 ， 道路与铁道工程， 2024， 硕士

【摘要】 半刚性基层作为我国高等级公路基层主要结构形式,在服役期间由于车辆重复荷载以及环境因素的不断作用,不可避免地出现裂缝甚至碎裂等病害,这大大降低了公路的服役性能,缩短了公路的使用寿命。如何高效地对半刚性基层病害进行处治和修复,已经成为道路交通养护的迫切需要。现阶段对于半刚性基层修复有诸多办法,其中注浆修复是较为常见的修复加固方法,但是由于部分常规注浆材料修复效果不佳,故使用自主设计制造的恒压注浆设备和团队创新研发的新型强渗透型高聚物注浆材料,采用室内试验、微观试验、足尺模型试验和数值模拟相结合的方法对渗透型高聚物注浆修复加固碎裂水泥稳定碎石的修复效果和修复机理进行深入研究。主要研究内容及结论如下:(1)对不同影响因素下渗透型高聚物注浆的水泥稳定碎石抗压特性进行研究,通过正交试验和控制变量试验来分析不同影响因素下的无侧限抗压强度和抗压回弹模量,并对无侧限抗压强度数据进行拟合。通过DIC数字图像相关技术,从位移和应变的角度对压缩破坏全过程分析。结果表明:渗透型高聚物注浆能够有效恢复和提升碎裂水泥稳定碎石的无侧限抗压强度和抗压回弹模量。(2)对渗透型高聚物注浆修复水泥稳定碎石韧性进行研究,通过正交试验和控制变量试验分析劈裂强度和极限拉应变影响,并对劈裂强度数据进行拟合。使用DIC数字图像相关技术,对劈裂破坏全过程进行研究。结果表明:注浆后试件的劈裂强度和劈裂破坏极限拉应变较注浆前有明显提升,渗透型高聚物有效制约了裂纹的开展,减缓裂纹的扩张速率,消耗并分散能量,使韧性能力得到增强。(3)对注浆修复前后的水泥稳定碎石进行了多种微观试验。结合SEM扫描电镜,探究了材料承载能力和韧性的提升机理。结合EDS能谱分析,研究了渗透型高聚物与碎石集料的界面微观形貌与元素组成。结合MIP压汞分析,发现注浆后的水泥稳定碎石孔隙结构等得到改善。最后通过XRD分析,得到渗透型高聚物是通过物理作用修复加固碎裂水泥稳定碎石。(4)开展足尺模型试验对渗透型高聚物注浆前后修复加固效果进行研究,使用FWD落锤式弯沉仪分析注浆前后弯沉情况,对注浆前后路面利用ABAQUS有限元软件建立路面结构三维模型。结果表明:渗透型高聚物注浆能够有效降低病害路面的面层指标SCI、基层指标BDI和路基指标D8,不同路面结构实测路表弯沉值与数值模拟计算弯沉值偏差均不大于20%。更多还原

【Abstract】 Semi-rigid grass-roots level,as the main structural form of grass-roots level of high grade highway in China,will inevitably show cracks and even cracks during service due to repeated vehicle loading and the continuous action of environmental factors,which greatly reduces the service performance of the highway and shortens the service life of the highway.How to efficiently treat and repair semi-rigid grass-roots level diseases has become an urgent need for road traffic maintenance.At this stage,there are many ways to repair the semi-rigid grass-roots level,of which grouting repair is a more common repair and reinforcement methods,but due to the poor repair effect of some of the conventional grouting materials,so the use of independently designed and manufactured constant-pressure grouting equipment and the team of innovative research and development of a new type of strong permeable polymer grouting materials,the use of indoor experiments,microscopic experiments,foot-scale modeling tests and numerical simulation combined with a combination of methods of permeable polymer grouting materials.Using a combination of indoor tests,micro-tests,foot-scale model tests and numerical simulations,the team carried out an in-depth study on the repair effect and repair mechanism of permeable high polymer grouting for repairing and reinforcing cracked cement-stabilized gravel.The main research contents and conclusions are as follows:(1)The compressive properties of cement-stabilized gravel with permeable polymer grouting under different influencing factors were investigated,and the unconfined compressive strength and compressive resilience modulus under different influencing factors were analyzed by orthogonal tests and controlled variable tests,and the unconfined compressive strength data were fitted.The whole process of compression damage was analyzed from the perspective of displacement and strain by DIC digital image correlation technique.The results showed that the permeable polymer grouting could effectively restore and enhance the unconfined compressive strength and compressive resilient modulus of fractured cement stabilized aggregates.(2)The permeable polymer grouting to repair the toughness of cement stabilized gravel was investigated,and the effects of splitting strength and ultimate tensile strain were analyzed by orthogonal and controlled variable tests,and the splitting strength data were fitted.Using DIC digital image correlation technology,the whole process of splitting damage was studied.The results show that the splitting strength and ultimate tensile strain of the specimens after grouting are significantly improved compared with those before grouting,and the permeable polymer effectively restricts the development of cracks,slows down the expansion rate of cracks,consumes and disperses the energy,so that the toughness capacity is enhanced.(3)Various microscopic tests were conducted on cement stabilized gravel before and after grouting repair.Combined with SEM,the enhancement mechanism of the bearing capacity and toughness of the material was investigated.Combined with EDS,the microscopic morphology and elemental composition of the interface between the permeable polymer and the crushed stone aggregate were investigated.Combined with MIP,it was found that the pore structure of cement stabilized aggregates was improved after grouting.Finally,through XRD analysis,it was obtained that the permeable polymers were used to repair and reinforce the fractured cement stabilized aggregates through physical action.(4)A foot scale model test was carried out to study the repair and reinforcement effect of permeable polymer before and after grouting,FWD hammer bending instrument was used to analyze the bending settlement before and after grouting,and ABAQUS finite element software was used to establish three-dimensional model of the pavement structure before and after grouting.The results show that:permeable polymer grouting can effectively reduce the surface index SCI,grass-roots index BDI and subgrade index D8 of the diseased pavement,and the deviation of the measured bending subsidence value of different pavement structures from the numerical simulation bending subsidence value is not more than 20%.更多还原