Incorporating Size Effects into Multiscale Adhesion Modelling of Bitumen-Mineral Interfaces

将尺寸效应纳入沥青-矿物界面的多尺度粘附建模中

• 批准号: EP/W000334/1
• 负责人: Gordon Airey
• 金额: $ 64.95万
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FW000334%2F1
• 关键词: Incorporating; Size; Effects; into; Multiscale

The UK's road network totals over 250,000 miles of paved roads providing a means for efficient distribution of goods and services, economic security and social prosperity. The entire road network has an asset value of £750 billion and as the UK's main transport infrastructure provides a vital service to road users, commerce and industry. However, the network requires constant upgrading, maintenance and rehabilitation with a predicted spend of £181bn required over the next 20 years.Over 95% of these paved roads are constructed from asphalt mixtures which comprise three principal components, namely, mineral aggregates (microns to centimetres), natural or added filler (< 63 microns) and bitumen (film thickness 10-20 microns). However, in spite of their importance, the deterioration of asphalt mixtures has never been fully understood or accurately predicted. The key reason is that the current means of assessing and predicting adhesive behaviour between the bitumen and the mineral aggregates does not account for size effects at the different material dimensional scales. These size effects result mainly from the variations of the bitumen film thickness, mineral surface roughness, air void radius, bitumen polarity distribution (molecular sizing) and mineral compositional distribution. Neglect of these size effects makes it impossible to accurately predict the asphalt mixture's distresses such as material fracture (traffic load induced fatigue cracking, non-load associated thermal cracking and age related cracking), moisture damage susceptibility (material disintegration and softening, stripping and fretting), potholes and other forms of severe surface deterioration, all of which are directly affected by the bitumen-mineral interfacial adhesive properties.The project aims to develop an overall 'adhesion analysis framework (AAF)' focusing on the measurement and prediction of interfacial adhesive properties between bitumen (binder) and mineral aggregates in asphalt mixtures using a size-affected multiscale experimental and modelling approach. Using a combination of experimental techniques, adhesion theories and material modelling approaches, size-dependent and size-independent material properties will be determined and scaled up from nano to micro to macroscale to predict the bitumen-mineral interface adhesive debonding properties of a range of asphalt mixture types. The research will use a combination of microscopy and spectroscopy imaging and molecular dynamics (MD) modelling at the nanoscale to predict bitumen-mineral interface adhesion and a range of size-independent material properties. The viscoelastic Griffith energy equilibrium principle will then be used at the microscale to produce a mechanics-based debonding initiation criterion incorporating the critical material size effects and the size-independent material properties obtained from the nanoscale MD simulations. The theoretical bitumen-mineral debonding criterion will then be verified by means of pull-off adhesion and cohesion testing incorporating different materials and size effects as well as loading and environmental conditions. The final scaling up effect will deal with crack (debonding) propagation developed through a Paris' law propagation model incorporating both size-dependent and size-independent materials parameters determined at the nano and microscales. These theoretical predictions will then be experimentally verified by a novel 'sandwich-cracking' test with prefabricated initial cracking dimensions together with material and conditioning variables. Finally, all these different multiscale effects will be incorporated into a multiscale modelling hierarchy for predicting adhesive failure and overall material response and delivered as a web-based opensource software and database. This user-friendly software will be used to design and produce better and long-lasting asphalt materials to ensure long-term sustainability of this key national asset.

英国的道路网络总计超过250,000英里的铺装道路，为有效分配商品和服务，经济安全和社会繁荣提供了一种手段。整个道路网络的资产价值为7500亿英镑，并且由于英国的主要运输基础设施为道路使用者，商业和行业提供了至关重要的服务。但是，该网络需要持续升级，维护和康复，预计在接下来的20年内需要支出1,10亿英镑的支出。其中95％的铺路道路是由沥青混合物建造的，这些混合物包括三个主要组件，这些组件包括三个主要组成部分，即矿物聚集体（厚度为center of centers of formons），自然填充（flosters offerens），添加了填充物（<63 micters）（<63 micr）（<63 micters）（<63 micr）（<63 micr）（<63 micr）（<63 micr）。然而，尽管它们的重要性，但沥青混合物的定义从未被充分理解或准确地预测。关键原因是当前的评估和预测沥青和矿物聚集体之间的粘合性行为的手段不能解释不同材料尺寸尺度的尺寸效应。这些尺寸效应主要是由于沥青膜厚度，矿物表面粗糙度，空气空隙半径，沥青极性分布（分子尺寸）和矿物组成分布的变化所致。忽视这些尺寸效果的使得无法准确预测沥青混合物的困扰，例如材料断裂（交通负荷引起的疲劳裂纹，与非负载相关的热裂纹和与年龄相关的裂纹），水分损伤易感性（材料崩解和软化，软化，剥离和脱落和脱衣），裂口和其他形式，由严重的表面脱位，这些菲斯特的距离，这些菲因的局限性，这些菲因夫妇的交织都是彼此的，这是所有菲斯特的交织。该项目旨在开发一个整体“粘附分析框架（AAF）”，重点介绍了使用尺寸受尺寸影响的多尺度实验和建模方法的沥青混合物中沥青（粘合剂）和矿物聚集体之间界面粘合性能的测量和预测。使用实验技术，粘合理论和材料建模方法，将确定尺寸依赖性和与尺寸无关的材料特性，并从纳米到微观到宏观尺寸，以预测沥青混合物范围的沥青阵线界面粘合性粘结性能。该研究将使用显微镜和光谱成像和分子动力学（MD）建模的组合来预测沥青阵线界面粘合剂以及一系列尺寸无关的材料特性。然后，将在微观尺度上使用粘弹性Griffith Energy等效原理，以产生基于力学的剥离启动标准，从而增加了临界物质尺寸效应和从纳米级MD模拟获得的尺寸独立的材料特性。然后，理论沥青矿物质剥离标准将通过拉动粘附和内聚力测试均具有不同的材料和尺寸效应以及负载和环境条件来验证。最终的扩展效果将处理通过巴黎定律传播模型开发的裂纹（剥离）传播，从而增加了在纳米和显微镜下确定的尺寸依赖性和与尺寸无关的材料参数。然后，这些理论预测将通过一种新型的“三明治裂缝”测试以及预制的初始裂纹维度以及材料和调节变量以及材料和条件变量来实验验证。最后，所有这些不同的多尺度效果将纳入多尺度建模层次结构，以预测粘合剂故障和整体材料响应，并作为基于Web的OpenSource软件和数据库提供。该用户友好的软件将用于设计和生产更好，持久的沥青材料，以确保该关键国家资产的长期可持续性。