This paper presents the details and results of the experimental investigations performed on the anchorages with multiple anchor rows of headed studs close to the edge, without and with supplementary reinforcement, loaded in shear towards the edge. The tests were performed on anchorages with 2 to 8 headed studs (one to 4 anchor rows) cast in concrete with 4 different levels of supplementary reinforcement. The test results highlight the influence of supplementary reinforcement on load carrying capacity of the anchorages. It is observed that for anchorages with multiple anchor rows, the failure crack always initiates from the back row of anchors, which is in contrast to the current assumption in EN1992-4 [1]. Due to this, more number of stirrups is activated in reality and the anchorage length of the activated stirrups is significantly more than that assumed in current model of EN1992-4. Consequently, for low amounts of supplementary reinforcement, the failure loads calculated by the current model are very conservative when compared to the experimental results. At high amounts of supplementary reinforcement, the concrete strut failure may govern the failure, which is ignored in the current models. Based on the evaluation of these test results, and supporting finite element calculations using 3D FE software MASA developed at University of Stuttgart, a realistic and rational model has been developed to predict the concrete edge failure loads for anchorages with supplementary reinforcement that is presented in accompanying paper.
The presence of supplementary reinforcement, in the form of edge reinforcement and stirrups, has a significant influence on the load-bearing capacity of anchorage groups with multiple anchor rows loaded in shear perpendicular to the edge. The current models available in the codes and standards are conservative for low to medium amounts of supplementary reinforcement but tend to be unsafe for high amounts of reinforcement. This paper presents the results of a comprehensive test program carried out to investigate the behavior of anchor groups with supplementary reinforcement loaded in shear toward the edge. The test results are discussed in detail to highlight the influence of supplementary reinforcement on the loadbearing capacity of the anchorages. Based on the evaluation of these test results, a realistic and rational model has been developed to predict concrete edge failure loads for anchorages with supplementary reinforcement that will be presented in another paper. K E Y W O R D Sanchorages, concrete edge failure, shear loads, supplementary reinforcement
The paper presents a new model for predicting the resistance of anchorages with supplementary reinforcement loaded in shear toward and perpendicular to the edge in case of reinforcement failure. The model is based on the evaluation of the results of a comprehensive test program performed on anchorages with multiple anchor rows and supplementary reinforcement, reported in an earlier paper. It is shown that the existing models available in the codes and standards are conservative for low to medium amounts of supplementary reinforcement but tend to be unconservative for high amounts of reinforcement. The new model is able to predict the failure loads corresponding to reinforcement failure under shear loads very well. The approach to incorporate other failure modes into the design model for anchorages with supplementary reinforcement under shear loads toward the edge will be presented in another paper. K E Y W O R D S analytical model, anchorage, shear load, supplementary reinforcement 1 | INTRODUCTIONIn an earlier paper, 1 details and results of the experiments performed on anchor groups with two to eight headed studs cast in unreinforced and reinforced concrete, loaded in shear perpendicular to the edge were reported. It was shown that the failure load for concrete edge failure of the anchorages with multiple anchor rows loaded in shear toward the edge can be significantly increased by using supplementary reinforcement in the form of stirrups and edge reinforcement. In case of anchorages with supplementary reinforcement, once the concrete cracks, the stirrups get activated and provide resistance to the applied shear loads until reinforcement yielding or bond failure occurs or hook (node) of the supplementary reinforcement fails. Thus, the shear strength of anchorage can be increased by increasing the amount of supplementary reinforcement. However, this increase in the shear capacity is capped by the strut (compression) failure of concrete. In current standards, such as EN1992-4, 2 ACI 318, 3 and fib bulletin 58, 4 the strut failure is neglected and a very conservative approach is given to consider stirrup yielding and node failure.In this paper, test results and observations are evaluated in detail and compared with the existing model given in EN1992-4 2 and the model proposed by Schmid 5 for anchorages with supplementary reinforcement loaded in shear toward the edge. Based on the detailed evaluation of test results, a new model is proposed for predicting the concrete edge failure loads for anchorages with supplementary reinforcement undergoing reinforcement failure by modifying the model proposed by Schmid. 5 It is shown that with the proposed model, the failure loads for the low to medium amount of reinforcement (where reinforcement failure dominates) can be predicted very well.For high amounts of reinforcement, it is possible that the concrete strut failure limits the failure load prior to reinforcement yielding. To consider this, an approach to
Abstract:In the accompanying paper, the details and results of the experimental campaign carried out on multiple row anchorages, without and with supplementary reinforcement, loaded in shear towards the edge were presented. It was shown that the models given in standards are insufficient to calculate the failure load for anchorages with supplementary reinforcement failing through concrete edge and reinforcement failure. This paper gives the details of a new analytical model developed to evaluate the failure load of anchorages with multiple anchor rows with supplementary reinforcement. The model is developed on the basis of the detailed evaluation of the results of an experimental campaign carried out on anchorages with up to four anchor rows. It has been shown that with the new model, the failure loads for the anchorages with supplementary reinforcement can be evaluated realistically considering different possible failure modes. In order to investigate the number of anchor rows participating to carry the shear loads, the experimental results are augmented through numerical simulations performed using software MASA at University of Stuttgart.
No abstract
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.