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: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=520841
• 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，沥青路面横向裂缝问题一直被认为是公路工程师面临的主要难题之一。人们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裂纹模型来解释的，该模型可以是基于经验的，也可以是基于力学的。然而，由于应用中的严重限制，这两种方法都无法充分解释这些裂纹的出现。 在该提案中，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) 粘结强度对裂缝过程的重要性 (3) 变化产生的应力温度和有缺陷的沥青材料的响应。所提出的方法是在施工后对压实过程产生的表面裂缝进行沥青结构建模。将利用有限元方法来模拟空气下降和路面温度对开裂结构应力应变状态的影响。将检查不同的情况，包括不同的性能、粘合值、温度变化率以及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受到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，这些条件会在热处理的沥青材料上产生机械应力。这项研究将对处理特别是热裂纹现象的基础基础产生重大影响。除了改善出行时间、道路安全和恢复公众对路面行业的信心之外，还将在初始投资、维护和修复成本方面节省大量经济费用。