Screwed‐head fastener is the common fabricated hold‐down bolt for steel structures and machine foundations. Although different models are available for evaluating its structural behavior, there are still aspects that need to be investigated. In particular, conflicting approaches for the design can be found among the European design‐oriented documents. Within this context, a comprehensive experimental study on screwed‐head fasteners under tensile loading was recently carried out at Milan Polytechnic. In this paper, some results are presented and commented which include (a) the presence of cracks and (b) the presence of supplementary reinforcement. In the discussion, predictive models are recalled demonstrating the need for a specific design approach, which should consider the geometry and the resistance of the fastening system, including that of the concrete member. Some design recommendations end the paper as useful guidance for the structural designer.

中文翻译：

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拉伸混凝土中钢筋混凝土螺钉头紧固件的性能和设计

螺丝头紧固件是钢结构和机器基础上常用的预制固定螺栓。尽管可以使用不同的模型来评估其结构行为，但仍有一些方面需要研究。尤其是，在欧洲面向设计的文件中可以找到相互矛盾的设计方法。在此背景下，米兰理工学院最近对拉伸载荷下的螺丝头紧固件进行了全面的实验研究。本文提出并评论了一些结果，其中包括（a）裂缝的存在和（b）补强的存在。在讨论中，召回了预测模型，表明需要一种特定的设计方法，该方法应考虑紧固系统的几何形状和阻力，包括具体成员。一些设计建议将本文作为对结构设计人员的有用指导。