Evaluation and Prediction of the Mechanical Behavior and Durability of FRC for Optimization of Design Criteria at Serviceability Limit States for Bridges

评估和预测 FRC 的机械性能和耐久性，以优化桥梁正常使用极限状态下的设计标准

基本信息

批准号：
RGPIN-2015-06694
负责人：
Charron, JeanPhilippe
金额：
$ 1.6万
依托单位：
École Polytechnique de Montréal
依托单位国家：
加拿大
项目类别：
Discovery Grants Program - Individual
财政年份：
2018
资助国家：
加拿大
起止时间：
2018-01-01 至 2019-12-31
项目状态：
已结题

来源：
https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=647245
关键词：
Evaluation Prediction Mechanical Behavior Durability

项目摘要

Large proportion of infrastructures, particularly bridge decks, are exposed to severe environmental conditions and present an early deterioration. Thus, some materials and design criteria used in construction do not allow reaching the expected lifetime of structures (over 75 years) without intervention. Promising methods to extend significantly the durability of infrastructures are to revise design criteria in service conditions for normal strength concretes (NSC) and promote utilization of Fibre Reinforced Concretes (FRC). Compared to NSC, FRC presents significant improvements in terms of mechanical properties and durability. However, a crucial lack of adapted design criteria in service impedes full exploitation of these materials in Canada.*******The general objective of the research program is to evaluate the mechanical behaviour and the durability of cracked NSC and FRC structural components to establish efficient design criteria in service conditions. The specific objectives are to: (a) evaluate water permeability of reinforced concrete under representative conditions of bridges, (b) reproduce the water transport and mechanical behavior of reinforced concrete under these conditions, (c) propose admissible crack widths and rebar stress levels applicable to various concrete categories to ensure durability of structures.*******The novelty of the scientific approach is to evaluate water permeability of concrete in the most representative conditions of bridges, which means on reinforced concrete sustaining permanent loads and randomly cracked. A unique experimental device developed recently will be used and improved; it allows accurate evaluation of water permeability, crack widths and rebar stresses in a reinforced concrete component simultaneously to the application of static, constant or cyclic loadings.*******The research program involving mainly 14 HQP will include experimental studies to evaluate the impact of FRC composition, design conditions, loading conditions, and environmental conditions on water permeability. Based on mechanical and permeability results obtained, nonlinear finite element analysis will also be conducted to reproduce crack patterns and water penetration in reinforced concrete structures in service, and to propose admissible crack widths and rebar stress levels for NSC and FRC in service conditions.*******In many cases current design criteria in service for reinforced concrete structures do not allow reaching their expected lifetime. Experimental and numerical studies of this research program will provide efficient admissible crack widths and rebar stress levels adapted for NSC and FRC to ensure long-term durability of structures. These design criteria in service will be proposed for introduction in construction codes. Their utilization will improve durability of infrastructures, thus lowering their maintenance and repair costs.******

大部分基础设施，尤其是桥梁甲板，暴露于严重的环境条件，并提出了早期的定义。这是建筑中使用的某些材料和设计标准，不允许在没有干预的情况下达到结构的预期寿命（超过75年）。显着扩展基础设施耐用性的有前途的方法是修改正常强度消耗（NSC）的服务条件下的设计标准，并促进纤维增强混凝土（FRC）的利用。与NSC相比，FRC在机械性能和耐用性方面具有显着改善。然而，至关重要的缺乏服务中的设计标准阻碍了加拿大对这些材料的全面开发。具体目的是：（a）在桥梁的代表性条件下评估了加固混凝土的水渗透性，（b）在这些条件下重现水的运输和钢构混凝土的机械行为，（c）提议的可接受的裂纹宽度，并提出了适用于各种混凝性的结构耐用性。大多数代表性的桥梁条件，这意味着在钢筋混凝土中持续永久载荷并随机破裂。最近将使用并改进开发的独特实验设备。它可以准确评估钢筋混凝土组件中的水渗透性，裂纹宽度和钢筋应力，仅用于应用静态，恒定或环状载荷的应用。基于获得的机械和渗透性结果，还将进行非线性有限元分析，以在服务中的加固混凝土结构中重现裂纹模式和水的渗透，并提出在服务条件下的NSC和FRC的可读裂纹宽度和NSC的可接受裂纹宽度和钢筋应力水平。******************在许多情况下，在当前的预期结构中，都无法达到促进的结构。该研究计划的实验和数值研究将提供有效的可允许的裂纹宽度和适用于NSC和FRC的钢筋应力水平，以确保结构的长期耐用性。这些服务中的这些设计标准将提议在施工法规中进行介绍。它们的利用将提高基础设施的耐用性，从而降低其维护和维修成本。******