Integrated approach for analyzing thermal effects on pavement construction-induced cracks

分析路面施工引起的裂缝热效应的综合方法

• 批准号: 5852-2011
• 负责人: AbdElHalim, Omar
• 金额: $ 1.53万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=568420
• 关键词: Integrated; approach; analyzing; thermal; effects

For 80 years, the problem of transverse surface cracking of asphalt pavements has been recognized as one of the major dilemmas facing highway engineers. Extensive research has been performed that produced large volumes of literature, and predictive models. Transverse cracks are traditionally explained through thermal cracking models which may be either empirically or mechanistically based. However, both approaches fail to adequately explain the appearance of these cracks due to serious limitations in their applications. In this proposal the problem will be considered in terms of the following elements: (1) Construction induced cracks causing the surface defects necessary to initiate transverse cracking (2) The importance of bond strength on the process of cracking (3) Stress generated by changes in temperature and the response of the defected asphalt material. The proposed methodology is to model the asphalt structure after construction with surface cracks resulting from the compaction process. A Finite element method will be utilized to simulate the effects of dropping air and pavement temperatures on the stress-strain state of the cracked structure. Different scenarios will be examined including different properties, bond values, rate of change of temperature and distribution and characteristics of the construction induced cracks. The results of the analytical phase will be used to develop a laboratory technique that accurately simulates field conditions when the pavement is subjected to changing temperatures. The laboratory model will generate stresses and strains caused by the changing temperatures and not the currently simulated conditions which induce mechanically generated stresses on thermally treated asphalt materials. This research will have a significant impact on the fundamental basis treating the phenomenon of thermal cracking in particular. Great economic savings on the initial investments and maintenance and rehabilitation costs will be realized, in addition to improved travel time, road safety and restoring the public confidence in the pavement industry.

80年来，沥青路面横向开裂问题一直是公路工程师面临的主要难题之一。已经进行了广泛的研究，产生了大量的文献和预测模型。横向裂纹传统上是通过热开裂模型来解释的，热开裂模型可以是基于经验的或基于机械的。然而，这两种方法都不能充分解释这些裂纹的出现，由于在其应用中的严重限制。 在本提案中，将根据以下要素考虑问题：（1）施工引起的裂缝，导致引发横向裂缝所需的表面缺陷（2）粘结强度对开裂过程的重要性（3）温度变化产生的应力和有缺陷的沥青材料的反应。所提出的方法是模拟施工后的沥青结构与表面裂缝所造成的压实过程。将利用有限元方法来模拟空气和路面温度下降对开裂结构的应力应变状态的影响。将检查不同的情况，包括不同的属性，粘结值，温度变化率和施工引起的裂缝的分布和特征。 分析阶段的结果将用于开发一种实验室技术，该技术可以准确模拟路面温度变化时的现场条件。实验室模型将产生由温度变化引起的应力和应变，而不是当前模拟的条件，其在热处理沥青材料上诱导机械产生的应力。这项研究将对特别是处理热裂纹现象的根本基础产生重大影响。除了改善旅行时间、道路安全和恢复公众对路面行业的信心外，还将节省大量的初始投资和维护及修复费用。