Lifetime Extension of Reinforced Concrete Slab-on-Beam Structures

钢筋混凝土梁板结构的使用寿命延长

• 批准号: EP/I018972/1
• 负责人: Janet Lees
• 金额: $ 24.53万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FI018972%2F1
• 关键词: Lifetime; Extension; Reinforced; Concrete; Slab

The lifetime extension of existing highway and building reinforced concrete infrastructure is a priority in terms of economic prosperity and a more sustainable future. The ability to reduce disruption, and amortise the embodied energy and the environmental impact of construction over an extended period will lead to direct, tangible and significant savings in energy and resource consumption. As construction typically accounts for up to 10% of the UK's GDP, and half of UK construction activity is associated with refurbishment and repair, it is clear that there is substantial scope to implement efficient technological innovations in the construction sector. In the UK, a major challenge is that, not only is the average age of our infrastructure increasing, but also the loading requirements are becoming more demanding. So the national pool of structures requiring intervention due to deterioration, changes of use, and/or a lack of strength is growing. For reinforced concrete (RC) structures, fibre-reinforced polymer (FRP) materials have been used as additional reinforcement to increase, or reinstate, strength capacity. These materials have a high strength-weight ratio, are durable and easy to install. To date, carbon FRP resin bonded strengthening systems have been the most common. The market share of FRP-strengthening applications has resulted in a proliferation of usage across the industry, and indeed continues to grow year on year. However, the development of our understanding has not kept pace with the growth in applications. There are significant gaps in our knowledge when typical large bridge or building structures and practical strengthening configurations are considered. The shear strengthening of RC structures is a particular challenge due to accessibility issues, the brittle nature of shear failures and the complex mechanics of the behaviour. Initial design guidance has played an important role in establishing the basis for the use of FRP systems but this guidance has necessarily drawn upon the results of specific studies which often only encompass a subset of possible parameters and interactions e.g. small-scale rectangular beams. However, there is an increasing body of evidence that suggests that a number of aspects of the fundamental shear behaviour are not captured in existing guidance. Recent studies have highlighted apparent contradictions between the predicted and observed behaviour of FRP strengthened large scale structures and structures with complex geometries. In particular, work at Cambridge University and Bath University have shown that in T-beams, which are considered representative of slab-on-beam structures, the current guidance can be unconservative yet for large scale rectangular beams, overly conservative. These contradictions pose difficulties since large-scale, slab-on-beam structures constitute a large proportion of the infrastructure that surrounds us and represents a target area for the use of FRP strengthening for lifetime extension. In the current project, a comprehensive experimental and analytical programme will be undertaken to understand the fundamental mechanics of beams strengthened in shear using bonded carbon FRP fabric systems. The effect of size will be investigated by considering strengthened T-beams with scales ranging from 'laboratory' scales to realistically sized structures found in practice. These targeted studies will lead to improved design approaches which reflect a comprehensive understanding of the failure mechanisms and the interactions that depend on the geometry and size of the structure. The deliverables will have a significant and timely impact through the provision of practical, safe and durable technological advances to enable the upgrading of existing RC structures to meet the demands of the 21st century.

延长现有公路的使用寿命和建设钢筋混凝土基础设施是经济繁荣和更可持续未来的优先事项。减少干扰的能力，以及在较长时间内摊销建筑的隐含能源和环境影响的能力，将导致能源和资源消耗的直接、有形和显著节省。由于建筑业通常占英国国内生产总值的10%，英国一半的建筑活动与翻新和维修有关，很明显，在建筑业实施有效的技术创新有很大的空间。在英国，一个主要的挑战是，不仅我们的基础设施的平均年龄在增加，而且装载要求也变得越来越苛刻。因此，由于恶化、用途改变和/或缺乏强度而需要干预的国家结构库正在增加。对于钢筋混凝土（RC）结构，纤维增强聚合物（FRP）材料已被用作额外的增强以增加或恢复强度能力。这些材料具有高强度重量比，耐用且易于安装。到目前为止，碳纤维增强塑料树脂粘结加固系统是最常见的。FRP强化应用的市场份额导致整个行业的使用量激增，而且确实在逐年增长。然而，我们认识的发展并没有跟上应用的增长。当考虑典型的大型桥梁或建筑结构和实际加固配置时，我们的知识存在重大差距。钢筋混凝土结构的抗剪加固是一个特殊的挑战，由于可达性问题，剪切破坏的脆性和行为的复杂力学。初始设计指南在建立FRP系统使用基础方面发挥了重要作用，但该指南必须借鉴特定研究的结果，这些研究通常仅包括可能参数和相互作用的子集，例如小规模矩形梁。然而，越来越多的证据表明，现有指南中没有涵盖基本剪切行为的许多方面。最近的研究突出了FRP加固大型结构和复杂几何结构的预测和观察行为之间的明显矛盾。特别是，剑桥大学和巴斯大学的工作表明，在被认为是梁上板结构的代表的T梁中，当前的指导对于大规模矩形梁可能是不保守的，过于保守。这些矛盾带来了困难，因为大型板梁结构构成了我们周围基础设施的很大一部分，并且代表了使用FRP加固以延长寿命的目标区域。在目前的项目中，将进行一项全面的实验和分析方案，以了解使用粘结碳纤维增强塑料织物系统进行剪切加固的梁的基本力学。尺寸的影响将被调查，考虑加强T型梁的规模范围从“实验室”的规模，以实际规模的结构在实践中发现。这些有针对性的研究将导致改进的设计方法，这些方法反映了对失效机制和依赖于结构几何形状和尺寸的相互作用的全面理解。这些成果将通过提供实用、安全和耐用的技术进步，使现有钢筋混凝土结构能够升级，以满足21世纪的需求，产生重大和及时的影响。

项目成果

Shear Strengthening of Reinforced Concrete T-beams with Carbon Fibre Reinforced Polymer Fabrics

碳纤维增强聚合物织物钢筋混凝土 T 梁的剪切加固

• 发表时间: 2016
• 作者: Foster RM

Experimental Investigation of Reinforced Concrete T-Beams Strengthened in Shear with Externally Bonded CFRP Sheets

• DOI: 10.1061/(asce)cc.1943-5614.0000743
• 发表时间: 2017-04-01
• 期刊: JOURNAL OF COMPOSITES FOR CONSTRUCTION
• 影响因子: 4.6
• 作者: Foster, Robert M.;Brindley, Monika;Evernden, Mark C.
• 通讯作者: Evernden, Mark C.

An upper-bound plastic approach to the capacity of reinforced concrete slab-on-beam structures strengthened in shear with externally bonded CFRP

外粘结 CFRP 抗剪加固钢筋混凝土板梁结构承载能力的上限塑性方法

• 发表时间: 2017
• 期刊: Advanced Composites in Construction, ACIC 2017 - Proceedings of the 8th Biennial Conference on Advanced Composites in Construction
• 作者: Foster R.M.

Shear Capacity of Reinforced Concrete T-Beams Retrofit with Externally Bonded CFRP Fabric: A New Perspective

• DOI: 10.1061/(asce)st.1943-541x.0002826
• 发表时间: 2020-12
• 期刊: Journal of Structural Engineering-asce
• 作者: R. Foster;C. Morley;J. Lees

Shear Capacity of Reinforced Concrete Subjected to Tension: Experimental Results and Analysis

受拉钢筋混凝土的剪切能力：实验结果与分析

• DOI: 10.1061/(asce)st.1943-541x.0001819
• 发表时间: 2017
• 期刊: Journal of Structural Engineering
• 影响因子: 4.1
• 作者: Foster R