Control of cracking and leakage due to shrinkage and temperature effects in structures using ECC and GFRP materials

控制使用 ECC 和 GFRP 材料的结构中因收缩和温度影响而导致的开裂和泄漏

• 批准号: 538053-2019
• 负责人: Lachemi, Mohamed
• 金额: $ 1.82万
• 依托单位: Ryerson University
• 依托单位国家: 加拿大
• 项目类别: Engage Grants Program
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=680396
• 关键词: Control; cracking; leakage; due; shrinkage

Restrained temperature and shrinkage strains are one of the major reasons for cracking in reinforced concrete structures. Such effect can cause serviceability problems which is of particular significance in the structural design of lifeline facilities such as liquid continuing structures and nuclear power plants. The prediction and control of crack widths in reinforced concrete structures made of normal concrete has been the subject of research for many years. However, there is still a lack of consensus on the design of reinforcement in base-restrained walls for crack control. The need for such study is even more for structures made of advanced materials such as ECC and GFRP. This study aims to investigate this matter through several experimental and analytical case studies. Three large-scale reinforced wall specimens with different materials and mix compositions will be casted, properly cured, and tested to determine how different types of material can affect the cracking pattern, the crack opening, and the strain profile produced by shrinkage and thermal effects. There are two main issues to be addressed through this study: 1) the width and pattern of temperature and shrinkage cracking in ECC and FRP-reinforced walls as compared to the customary normal concrete walls typically used in today's practice, 2) cracking due to thermal effects derived from two main factors - seasonal temperature variations and early-age thermal contraction. The goal is to contribute to the improvement of concrete technology and to provide engineers with practical design guidelines. The main objective is to study the potential improvements in cracking behavior of base-restrained walls using newly developed materials such as ECC and GFRP to withstand extreme weather conditions, similar to those encountered in Canada. In this relation, it is proposed that the time-dependent effects due to shrinkage and temperature change be induced in specimens made of different materials and the development of cracking in them be monitored and examined over time.

约束温度和收缩菌株是钢筋混凝土结构破裂的主要原因之一。这种影响可能导致可维修性问题，这在液态持续结构和核电站等生命线设施的结构设计中特别重要。多年来，由正常混凝土制成的钢筋混凝土结构中的裂纹宽度的预测和控制已有很多年了。但是，仍然缺乏在基础壁中的加固，无法进行裂纹控制。对于由ECC和GFRP等晚期材料制成的结构，对此类研究的需求更高。这项研究旨在通过一些实验和分析案例研究研究此问题。将施放，适当固化并测试三个带有不同材料和混合成分的大规模增强壁样本，以确定不同类型的材料如何影响裂纹模式，裂纹打开以及通过收缩和热效应产生的应变曲线。通过这项研究有两个主要问题：1）与通常在当今实践中通常使用的习惯正常混凝土壁相比，ECC和FRP增强壁的温度和收缩裂纹的宽度和模式以及收缩裂纹的裂纹； 2）由于季节性温度量和早期热量量的两个主要因素而产生的热效应。目的是为改进混凝土技术做出贡献，并为工程师提供实用的设计准则。主要目的是使用新开发的材料（例如ECC和GFRP）研究基础壁的开裂行为的潜在改善，以承受与加拿大遇到的极端天气条件。在这种关系中，建议在不同材料制成的标本中诱导因收缩和温度变化引起的时间依赖性效应，并随着时间的推移监测和检查它们的开裂和检查。