Resolving Bond Challenges in Reinforced Concrete and Masonry Structures

粘结的存在，也就是钢筋与周围胶凝材料之间的应变相容性，是钢筋混凝土和砌体构件分析中使用的基本假设之一，它影响构件的延性以及剪切和弯曲响应。因此，为了确保适当的加固细节，以及钢筋混凝土和砌体结构的安全性和经济性，对粘结性的准确评估是必要的。**虽然砖石是最古老的建筑材料之一，但这方面的研究很少。因此，设计代码的某些方面缺乏一致性，并且不是基于理性的。一个典型的例子是，美国砌体标准对钢筋的开发和拼接的要求比加拿大标准的要求要保守得多，特别是对于较大的钢筋尺寸。据推测，将100多年来对钢筋混凝土粘结研究的经验教训引入砌体研究，将使这两套标准合理化，并重新评估规范条款。这将基于一个独特而全面的实验计划，其中包括分析关系的发展，以验证本研究的假设。此外，最近桥梁倒塌和对国家基础设施状况的暴露突出表明需要对现有结构采用适当的评价技术。历史上的钢筋混凝土结构可能是用普通钢筋或不符合现代标准的变形钢筋建造的。据推测，这些钢筋的粘结性能不同于现代变形钢筋。为了达到提高实习工程师评估技术的目标，需要进行实验和分析工作。** 3名硕士生和3名博士生将参与拟进行的研究。这些学生将在对加拿大经济具有战略意义的领域接受培训。******

The existence of bond, otherwise described as strain compatibility between the reinforcement and the surrounding cementitious materials, is one of the fundamental assumptions used in the analysis of reinforced concrete and masonry members, and influences member ductility as well as shear and flexural response. An accurate assessment of bond is therefore necessary to ensure proper detailing of the reinforcement, and so the safety and economy of reinforced concrete and masonry structures.** Though masonry is one of the oldest building materials, research in this area has been quite minimal. As a result, some aspects of design codes lack consistency and are not rationally-based. A case in point is that the requirements for the development and splicing of reinforcement, as provided by the U.S. masonry standard, are significantly more conservative than those provided by the Canadian standard, particularly for larger bar sizes. It is hypothesized that bringing the lessons learned from 100+ years of study of bond in reinforced concrete to masonry research will allow for a rationalization of these two sets of standards and a re-evaluation of code provisions. This will be based on a unique and comprehensive experimental program which will include the development of analytical relationships to verify the hypothesis of this study. ** Furthermore, recent bridge collapses and exposés on the state of the nation's infrastructure have highlighted the need for proper evaluation techniques for existing structures. Historical reinforced concrete structures may have been built with plain reinforcement, or deformed bars that do not conform to modern standards. It is hypothesized that the bond performance of these bars differs from that of modern deformed bars. Experimental and analytical work is required to reach the goal of improving evaluation techniques for practicing engineers.** Three M.Sc. students and three Ph.D. students will participate in the proposed research. These students will be trained in an area that is strategically important to Canada's economy.******