Multiscale Constitutive Model Development for Deteriorating Concrete

劣化混凝土的多尺度本构模型开发

• 批准号: RGPIN-2022-04668
• 负责人: Erkmen, Emre
• 金额: $ 2.26万
• 依托单位: Concordia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=746382
• 关键词: Multiscale; Constitutive; Model; Development; Deteriorating

Majority of civil infrastructure is constructed using concrete material. For concrete, deterioration of mechanical properties is an important problem that effects the public safety and economy. Understanding the current state of deteriorated concrete is essential to evaluate the residual capacity. On the other and, understanding the residual capacity of an existing structure is essential when it comes to making decisions about retrofitting, demolishing or continuing with operations. Aging deterioration and/or failure of concrete material under excessive loads manifests itself by crack development. In Canada, freeze-thaw cycles and Alkali-Silica Reaction (ASR) in humid environment are major reasons of crack development in concrete. On the other hand, excessive loading may also occur due to earthquakes or explosions. During the service life of a concrete structures, it is possible to conduct non-destructive testing and/or analysis based on computer modelling for condition assessments purposes. Non-destructive testing such as image processing, ultra-sonic-devices and/or elastic wave propagation can help identify the crack configurations. There is currently a significant need in the industry for residual capacity evaluation tools for aging concrete structures. The currently available tools offer limited modelling capabilities when it comes to evaluating the residual capacity of an existing deteriorated structure because safety factors and simplifications proposed by the guidelines during the design stage of new structures cannot be adopted to cover up modelling errors. It is crucial to predict the structural behaviour based on its existing condition to identify realistic failure scenarios. The proposed research aims to develop a constitutive model for concrete material considering the existing crack configuration that can be adopted in structural analysis up to failure. For this purpose, the proposed research aims to develop a computational framework that incorporates the heterogenous nature of the concrete material such that crack development at the meso-scale and uncertainties in the distributions of the aggregate and cracks can be considered. The proposed computational framework can be used for residual capacity analysis of structures, and as such it will provide engineers a thorough and practical basis on which to decide whether to resume continual operation, retrofit or demolish an existing concrete structure. By developing capabilities to assess the residual capacity of deteriorated concrete structures, the proposed research addresses a timely need that is complementary to advancements in non-destructive testing capabilities that identify existing cracks. Accurate evaluation of the residual capacity will support a well-informed decision-making process between public safety and economy, when questions are raised regarding the health and safety of existing concrete structures.

大部分民用基础设施都是用混凝土材料建造的。对于混凝土而言，力学性能劣化是影响公共安全和经济的重要问题。了解劣化混凝土的现状对于评估剩余能力是至关重要的。另一方面，当涉及到关于翻新、拆除或继续运营的决策时，了解现有结构的剩余能力是至关重要的。混凝土材料在超载作用下的老化、劣化和/或失效表现为裂缝的发展。在加拿大，潮湿环境中的冻融循环和碱-硅酸反应(ASR)是混凝土裂缝发展的主要原因。另一方面，地震或爆炸也可能导致超载。在混凝土结构的使用寿命期间，可以进行基于计算机建模的无损检测和/或分析，以进行状况评估。图像处理、超声波装置和/或弹性波传播等无损检测技术可以帮助识别裂纹的形态。目前，该行业对老化混凝土结构的剩余容量评估工具有很大的需求。目前可用的工具在评估现有劣化结构的剩余能力时提供的建模能力有限，因为不能采用指南在新结构设计阶段提出的安全系数和简化来掩盖建模错误。根据结构的现有状态来预测结构的行为，以识别现实的失效情景是至关重要的。提出的研究目的是建立混凝土材料的本构模型，该模型考虑了现有的裂缝形态，可用于结构分析直至破坏。为此，拟议的研究旨在开发一个计算框架，纳入混凝土材料的非均质性质，以便可以考虑细观尺度的裂缝发展以及骨料和裂缝分布的不确定性。建议的计算框架可用于结构的剩余能力分析，从而为工程师决定是否继续运营、改造或拆除现有混凝土结构提供了全面和实用的依据。通过发展评估劣化混凝土结构剩余能力的能力，拟议的研究解决了一个及时的需求，这是对识别现有裂缝的无损检测能力进步的补充。当对现有混凝土结构的健康和安全提出问题时，对剩余能力的准确评估将有助于在公共安全和经济之间进行知情的决策过程。