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.

大多数民用基础设施都是使用混凝土材料建造的。对于混凝土来说，力学性能的恶化是影响公共安全和经济的重要问题。了解劣化混凝土的当前状态对于评估剩余能力至关重要。另一方面，在做出有关改造、拆除或继续运营的决策时，了解现有结构的剩余容量至关重要。混凝土材料在过大荷载下的老化恶化和/或失效表现为裂纹的发展。在加拿大，潮湿环境中的冻融循环和碱硅反应（ASR）是混凝土裂缝发展的主要原因。另一方面，由于地震或爆炸也可能发生超载。在混凝土结构的使用寿命期间，可以基于计算机建模进行无损测试和/或分析以进行状态评估。图像处理、超声波设备和/或弹性波传播等无损检测可以帮助识别裂纹结构。目前，业界非常需要老化混凝土结构的剩余能力评估工具。在评估现有退化结构的剩余能力时，当前可用的工具提供的建模功能有限，因为无法采用新结构设计阶段指南中提出的安全系数和简化来掩盖建模错误。根据现有条件预测结构行为以识别实际的故障场景至关重要。所提出的研究旨在开发一种考虑现有裂缝配置的混凝土材料本构模型，该模型可用于直至失效的结构分析。为此，拟议的研究旨在开发一个计算框架，该框架结合了混凝土材料的异质性质，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。所提出的计算框架可用于结构的剩余能力分析，因此将为工程师提供全面且实用的基础，以决定是否恢复持续运行、改造或拆除现有混凝土结构。通过开发评估劣化混凝土结构剩余能力的能力，拟议的研究满足了及时的需求，与识别现有裂缝的无损检测能力的进步相补充。当提出有关现有混凝土结构的健康和安全的问题时，对剩余容量的准确评估将支持公共安全和经济之间的明智决策过程。