论文总字数：35679字

摘 要

随着道路工程的蓬勃发展，我国路面结构出现了越来越多的老化沥青混凝土与新沥青混凝土相接的情况，其中以路面坑槽病害的挖除再填补最为常见。修补后的坑槽在使用过程中，其坑槽壁面接缝很容易产生开裂和局部破损，并不断延伸，即“界面早期破坏”。这种现象使维修效果大打折扣，不仅降低了公路的使用性能，而且增加了养护维修费用。因此，本文主要针对坑槽修补后的二次破坏，研究和分析新老沥青混凝土交界面的破坏机理，并运用数值模拟技术分析弹性模量对新老沥青混凝土界面承受剪应力大小的影响，最后设计室内试验来模拟老化沥青与填补沥青相接的情况，并求出其平均抗剪强度，分析抗剪性能的变化规律，为实际工程的应用提出建议。

首先，本文对坑槽修补后其界面发生早期破坏的原因进行分析，对新旧沥青混凝土界面的破坏类型进行分类。本文通过调研将界面早期破坏的原因分为三类，包括水损害、受力损害、技术因素导致破坏；将界面的破坏类型分为四类，包括沥青与集料之间的剥落、内聚破坏、界面破坏、混合破坏。并进一步对各种因素的影响大小及不同破坏类型的原因进行分析。研究结果有利于本文在数值模拟中对参数的拟定。

其次，为了获得新老沥青混凝土相接的路面在实际路况中承受剪应力作用的规律，因此本文采用ABAQUS软件对标准行车荷载作用下的新老沥青混凝土拼接路面进行了计算，并通过改变表面层的弹性模量和表面层厚度来探索剪应力变化规律。研究结果可以与本文设计的室内试验进行对比，更好的说明剪应力对界面破坏的重要影响。

最后，本文设计室内试验来分析新老沥青混凝土界面抗剪性能的变化规律。通过老化试验来实现沥青混合料的不同老化程度（不同回弹模量）；通过碾压法，利用环氧树脂实现新老沥青混合料的拼接；通过UTM直剪试验测定新老沥青界面的平均抗剪强度；通过单轴压缩试验测定各试件的实际回弹模量。综合分析回弹模量对新老沥青混凝土界面抗剪性能的影响，分析破坏面的类型及产生原因。研究结果结合数值模拟规律可以为坑槽修补材料提供依据，改善界面早期破坏的问题，降低养护维修费用。

关键词：沥青混凝土,抗剪性能,数值模拟,室内试验,界面早期破坏

Abstract

With the development of the highway in our country, there are more and more road facing the problem that the aged asphalt concrete connect to the new asphalt concrete. In most cases,we usually dig out the old asphalt concrete and refill the new asphalt concrete to deal with the potholes problems.But the repaired potholes often get some cracks and local destruction at the interface,and the diseases keep growing which is called interface distress. It is not only reduces the performance of the road, but also increases the maintenance cost. Therefore, this paper mainly focuses on the secondary damage after repairing pits.This paper researches and analyzes the failure mechanism of the interface between the new and old asphalt concrete, and uses numerical simulation techniques to analyze the effect of elastic modulus on the shear stress experienced by the interface between new and old asphalt concrete. An indoor test was designed to simulate the connection of aged asphalt and filled asphalt. The average shear strength was calculated and the variation of shear resistance was analyzed to provide recommendations for practical engineering applications.

First of all, this paper analyzes the causes of the early damage of the interface after pit repair, and classifies the damage types of the old and new asphalt concrete interfaces. In this paper, the reasons for the early destruction of the interface are divided into three categories, including water damage, mechanical damage, and technical factors; and the interface failure types are divided into four categories, including flaking and cohesive failure between asphalt and aggregates, interface destruction, mixed destruction. This paper analyzes the impact of various factors and different damage types. The research results are helpful to the formulation of parameters in numerical simulation.

Secondly, in order to obtain the regularity of shear stress acting on the road surface with new and old asphalt concrete in the actual road conditions, this paper uses ABAQUS software to calculate the new and old asphalt concrete spliced road surface under standard vehicle load. The change of shear stress was explored by changing the elastic modulus of the surface layer and the thickness of the surface layer. The results of the study can be compared with the laboratory tests designed in this paper to better illustrate the important impact of shear stress on interface failure.

Finally, this paper designs an indoor test to analyze the change law of the shear strength of the interface between the new and old asphalt concrete. Aging test to achieve different aging degree of asphalt mixture (different resilience moduli),and use epoxy resin to achieve new and old asphalt mixture splicing.Through UTM direct shear test,it can determine the interface average Shear strength.The actual rebound modulus of each test piece was determined by a uniaxial compression test. This paper analyzes the impact of the modulus of resilience on the shear strength of the interface between new and old asphalt concrete, and analyzes the type of failure surface and its causes. The results of the study combined with numerical simulations can provide evidence for pit repair materials, and improve the early failure of the interface, and reduce maintenance costs.

KEY WORDS: Asphalt concrete, Shear resistance, Numerical simulation, Laboratory test, Interface distress

目录

摘要 I

Abstract II

第一章 绪论 1

1.1研究背景与意义 1

1.2国内外研究现状 1

1.2.1新老沥青混凝土界面破坏机理研究 1

1.2.2沥青混凝土抗剪强度测试试验 2

1.2.3不同介质接触面剪切力学性能的研究 3

1.3主要研究内容 3

1.4研究方案和技术路线 4

1.4.1研究方案 4

1.4.2技术路线 5

第二章 沥青路面坑槽修补界面早期破损机理研究 7

2.1坑槽壁面的水损害 7

2.1.1水降低了沥青与集料之间的粘附性 7

2.1.2水力冲刷现象使沥青剥落 7

2.2坑槽壁面的受力破坏 8

2.3新旧沥青混凝土交界面的破坏类型 9

2.4本章小结 10

第三章 基于ABAQUS的新老沥青混凝土界面剪应力分析 11

3.1新老沥青混凝土拼接结构的有限元模型 11

3.1.1路面结构选择方案 11

3.1.2有限元模型的建立及结构参数的设定 11

3.2新老沥青混凝土界面的剪应力计算 13

3.2.1表面层为4cm的模拟结果 13

3.2.2表面层为6cm的模拟结果 15

3.2.3表面层为8cm的模拟结果 17

3.3新老沥青混凝土界面剪应力分析 18

3.3.1变量选取 18

3.3.2剪应力影响因素分析 19

3.4本章小结 19

第四章 室内试验模拟新老沥青混合料界面破坏 21

4.1沥青混合料的配合比设计 21

4.2室内试验模拟新老沥青拼接结构 25

4.3回弹模量与抗压强度测试 26

4.4新老沥青混合料界面抗剪性能测试 28

4.5室内试验与数值模拟对比分析 32

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