Nowadays virtually all‐concrete construction uses reinforcement with deformations rolled or indented on the bar surface to improve bond between bar and concrete, but many older structures built with plain surface bars remain in service. The increasing need for assessment of existing construction means there is a continuing need for information on their performance. Research into plain surface bars essentially ceased when ribbed bars became established, and plain bars have consequently been bypassed in developments in understanding and modeling of bond since 1960. The profession's ability to numerically model behavior of concrete structures has expanded dramatically since plain surface reinforcement was discontinued. The option of numerically modeling may be particularly important for assessment of existing structures with noncompliant details. Although the fib Model Code 2010 includes a local bond–slip model for plain surface bars, information on the derivation of the model and supporting evidence of its validation are not available. The current paper analyses data on bond–slip behavior of plain surface bars and demonstrates shortcomings in the fib model. An improved model is proposed and verified against test data from an independent source.

中文翻译：

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平面粘结的局部粘结-滑移模型

如今，几乎所有的混凝土结构都使用钢筋，钢筋在钢筋表面上轧制或压入，以改善钢筋和混凝土之间的结合力，但是许多使用普通表面钢筋建造的较旧的结构仍然可以使用。对现有建筑进行评估的需求日益增加，这意味着持续需要有关其性能的信息。自从肋骨钢筋建立起来以来，对平面钢筋的研究基本上就停止了，因此，自1960年以来，对粘结的理解和建模的发展一直绕开了平面钢筋的研究。自从停止平面钢筋加固以来，该专业对混凝土结构行为进行数值模拟的能力得到了极大的扩展。 。数值建模的选项对于评估具有不合规细节的现有结构可能尤其重要。fib Model Code 2010包括用于平面筋的局部粘结滑移模型，尚无有关该模型推导的信息以及对其进行验证的支持证据。当前的论文分析了有关平面棒的粘结-滑移行为的数据，并证明了fib模型的缺点。提出了一种改进的模型，并针对来自独立来源的测试数据进行了验证。