Experimental study on the influence of different types of nuts on the anchoring performance of steel bars

How to choose the appropriate nut is the key to achieving reliable anchoring of steel bars in prefabricated components. This study investigated the effects of different nut types on the anchorage performance of steel bars with diameters from 8mm to 28mm. A comprehensive program of pull-out test was carried out to evaluate the failure-to-yield ratio and characterize the failure modes. Subsequently, simplified mechanical model analysis was developed. The test results demonstrated that for specimens with bar diameters ranging from 8 mm to 20 mm, the stainless steel flange nut exhibited the best anchorage perfor-mance, whereas the anchor plate nut performed the poorest. For bar diameters between 22 mm and 28 mm, the carbon steel flange nut showed the optimal performance, and with the anchor plate nut again being the least effective. Flange nut generally outperformed combination nut, which is at-tributed to their superior structural integrity. Considering both anchorage performance and material cost, carbon steel flange nuts present the best choice.