Search

Highlights • Experimental investigation was conducted on shear behavior of SSG in PC decks. • The interface shear force -slip non-linear relations of the specimens were obtained. • The effect of different parameters on behavior of specimens was investigated. • The failure modes, ductility, bearing capacity of test specimens were analyzed. • The existing design formulas may be utilized to calculate shear capacity of SSG. Abstract In order to study the shear behavior of a group of shear studs placed on a composite beam, a total of 16 pushout tests were conducted, including 4 specimens with cast-in-place (CIP) concrete decks and 12 specimens with precast concrete (PC) decks. The primary parameters considered include reserved hole shape, loading path, and deck casting method. Through the experiment, the interface shear force-slip curves and the failure modes of shear stud groups (SSGs) in both CIP and PC decks under monotonic and repetitive loads were obtained. The results show that the shear behavior of the SSGs in square reserved holes is more favorable than that in circular reserved holes, the shear strength of SSGs in PC decks is smaller than that in CIP decks under monotonic loads. The general failure modes for a SSG are the cutoff of stud shanks and the damage of root welds at studs. While the shear strength of a SSGs in PC decks is similar to that in CIP decks under repetitive loads, ensuring the ductile failure mode of stud fracture and the shear capacity not smaller than that stipulated in the design code for reinforced concrete (RC) structures, even without using any rebar in a reserved hole. The peak interface shear force and the trend of interface shear force-slip curves under repetitive loads are also similar to that under monotonic loads, although the interface slip corresponding to peak force under monotonic loads is smaller than that under repetitive loads. The study results indicate that the SSG in a PC deck can be fully utilized and the existing design formulas almost may be utilized to calculate shear capacity of shear stud groups. [ABSTRACT FROM AUTHOR]

The precast concrete segments of wind turbine hybrid towers are usually lifted and installed using the pre-installed lifting anchors with supplementary reinforcements. The lifting anchors are made of steel plate and the supplementary reinforcements are often arranged near the lifting anchors to enhance their anchoring performance. This lifting system including the reinforcement configuration is presented in existing design codes, but the design recommendation and calculation method of ultimate capacity are not provided. It is necessary to explore the pull-out behavior of the lifting anchor considering the effects of reinforcements. Therefore, a comprehensive investigation on the pull-out behavior of the lifting anchor is conducted in this paper, by using the precast concrete segments of hybrid tower as a carrier. Four specimens based on the actual dimension of precast concrete segment of hybrid tower were tested under cyclic pull-out loading, and the failure modes as well as the ultimate capacity were analyzed. The verified finite element (FE) models were established based on the test results, and mechanical analysis were performed to reveal the pull-out mechanism of the lifting anchor. Subsequently, the parametric analysis was conducted to explore the sensitive parameters of the lifting anchor's pull-out performance. The accuracy and applicability of the calculation methods for ultimate pull-out capacity in existing design codes and literatures were evaluated based on the test results. Lastly, a practical calculation method for the ultimate pull-out capacity of lifting anchor was proposed based on theoretical model and regression analysis. The proposed method can provide a reference for the lifting design of precast concrete segments of wind turbine hybrid towers. • 4 specimens with the specialized lifting anchor based on the actual size of precast concrete segment were tested under cyclic pull-out loading. • The verified FE models were established, and mechanical analysis were performed to reveal the pull-out mechanism of the lifting anchor. • The parametric analysis was conducted to explore the sensitive parameters of the lifting anchor's pull-out performance. • The accuracy and applicability of the existing calculation methods for ultimate pull-out capacity were evaluated based on the test results. • A practical calculation method for the pull-out capacity of lifting anchor was proposed based on theoretical model and regression analysis. [ABSTRACT FROM AUTHOR]