Shear capacity of reinforced concrete one-way slabs without shear reinforcement under single loads

单一荷载作用下无剪钢筋钢筋混凝土单向板的抗剪承载力

• 批准号: 253183198
• 负责人: Professor Dr.-Ing. Josef Hegger
• 金额: --
• 依托单位: Lehrstuhl und Institut für Massivbau
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/253183198?language=en
• 关键词: Shear; capacity; reinforced; concrete; way

The present models for the shear capacity of reinforced concrete slabs without shear reinforcement were mostly developed based on the knowledge of the shear-bearing behaviour of beams. The slab-loadbearing behaviour under single loads is considered by different approaches for an effective width, which capture the actual bearing behaviour insufficiently. According to recent research, the influence of the shear-span-to-depth ratio and the load transfer due to a direct compression strut differs for slabs and beams. In particular, the interaction between arching action and effective width for shear depending on the static system and the moment-shear ratio seems to be of significance. In case of simultaneously acting single and line loads, the influence of the greater compression force due to bending is not clarified, especially for haunched slabs with inclined compression struts.The overall objective of the research project is to analyse the shear-bearing behaviour of one-way concrete slabs without shear reinforcement under single loads and to develop a consistent model for the shear capacity. In particular, the influences of the support conditions, the degree of restraint and the static system (cantilever slab, single- and multi-span slab), the shear-span-to-depth ratio and the reinforcement ratio on the load spreading of a single load and the shear capacity should be investigated. By tests on slab stripes and wide slabs, the influence of the effective width is evaluated. In addition, the interaction of multiple single loads should be analysed. The open questions are adressed by experimental and theoretical investigations. Starting point for the theoretical investigations are the present models for shear design. Based on the shear tests on slabs under single loads from literature, a database is established in order to evaluate the existing approaches. The experimental investigations extend of the database for parameters, which have not been studied so far. By evaluation of the tests and parameter studies on nonlinear finite-element models, the different contributions to the shear capacity depending on the moment-shear interaction are quantified. In combination with the experimental test data a sufficient database is provided allowing to develop an extended model for the shear capacity of concrete slabs under single loads.

目前的模型基于对梁的剪切行为的了解，主要开发了没有剪切钢筋的混凝土板的剪切能力。单个负载下的平板载荷行为是通过不同方法来考虑有效宽度的，从而捕获实际的轴承行为不足。根据最近的研究，由于直接的压缩支撑杆的影响，剪切 - 跨度与深度比的影响在平板和光束方面有所不同。特别是，根据静态系统和力矩剪切比的不同，抗剪切的拱形作用与有效宽度之间的相互作用似乎很重要。如果同时起作用单和线负荷，则无法澄清弯曲引起的更大的压缩力的影响，尤其是对于具有倾斜压缩撑杆的仰望的平板。研究项目的总体目标是分析单向混凝土板在单个载荷下无剪切的单向混凝土板的剪切行为，以在单个载荷下进行剪切，以使剪切能力保持一致的模型。特别是，支撑条件的影响，约束程度和静态系统（悬臂平板，单跨板和多跨度板），剪切 - 跨度与深度比以及增强比对单个负载的负载扩散以及剪切能力的载荷扩散。通过对平板条纹和宽板的测试，评估了有效宽度的影响。另外，应分析多个单个载荷的相互作用。实验和理论研究使公开问题受到了尊重。理论研究的起点是剪切设计的当前模型。基于文献单个负载下对平板的剪切测试，为了评估现有方法，建立了一个数据库。实验研究扩展了数据库的参数，到目前为止尚未研究。通过评估非线性有限元模型的测试和参数研究，对剪切能力的不同贡献取决于力矩剪切相互作用。结合实验测试数据，提供了足够的数据库，允许在单个载荷下开发一个剪切能力的扩展模型。