Shear behavior of select post-installed mechanical concrete fasteners
Description
This research addresses experimental and analytical studies on the shear behavior of post-installed mechanical concrete fasteners, primarily powder-actuated fasteners and concrete screws. The use of these types of fasteners is increasing in structural applications. Behavioral models based on experimental and analytical results have been developed to guide the design of anchorage to concrete using post-installed mechanical fasteners Single fastener tests have been performed in untracked concrete, in order to determine the basic and characteristic shear behavior offasteners. Fasteners with different lengths and diameters have been tested to determine the effect of embedment length and fastener anchor diameter on the shear behavior offasteners. Concrete slabs of different strengths were used for fastener tests to explore the effect of concrete strength. Cracked concrete slabs were used to test fasteners in cracks to examine the influence of the presence of cracks on the shear behavior of fasteners. Double fastener group tests were also performed to investigate the group effect on the shear behavior of fasteners Behavioral models have been developed to investigate the unique factors affecting the properties ofpost-installed mechanical fasteners loaded in shear. Design equations have been proposed based on the experimental and analytical results Knowledge obtained from this study will be useful for the design of anchorage to concrete. The design equations and recommendations achieved from this research will be submitted to the American Concrete Institute (ACI) for possible adoption to ACI 318, A CI 440, ACI 355 and other relative codes and standards in future Results of this study indicated that current provisions for design of anchorage to concrete located in the Appendix D of ACI 318-05, which are not meant to be applied to power-actuated or concrete screws, are not applicable to the design of anchorage to concrete using power-actuated fasteners or concrete screws. Behavioral models for concrete screws were proposed in this study. Proposed behavior models can predict the shear behavior of concrete screws very well with respect different concrete strengths and conditions (presence or absence of cracking), different screws sizes, and different screw shank diameter to embedment depth ratios