6 results
Search Results
Now showing 1 - 6 of 6
Article Citation - WoS: 1Citation - Scopus: 1Experimental Determination of Resistance Characteristics of Support Details Used in Prestressed Concrete Bridge Girders(Asce-amer Soc Civil Engineers, 2009) Baran, Eray; Rohne, Ryan; French, Catherine E.; Schultz, Arturo E.Static load tests were performed on support details used at the ends of prestressed concrete pedestrian bridge girders to determine the resistance characteristics of girder supports in the direction perpendicular to the longitudinal axis of the girders. The specimens tested represent support details that have also been widely used in prestressed concrete highway bridges in Minnesota and in other states. Two specimens, one representing the free-end detail and one representing the restrained-end detail were subjected to a combination of vertical and lateral loads. The applied loading was intended to simulate the loading conditions to which the girder ends would be subjected in the event of an over-height vehicle collision with the bridge. The tests revealed two types of lateral load resisting mechanisms depending on the type of support detail. The specimen with the free-end detail resisted the lateral loading through sliding friction between the components of the support assembly. Deformation of this specimen was a combination of shear deformation of the bearing pad and sliding of various support components. The restrained-end detail exhibited larger lateral load capacity than the free-end detail due to the resistance provided by the anchor rods that were intended to prevent the lateral movement of the girder ends. Failure of the specimen with restrained-end detail was due to the concrete breakout and bending of the anchor rods.Article Citation - WoS: 69Citation - Scopus: 78An Experimental Study on Channel Type Shear Connectors(Elsevier Sci Ltd, 2012) Baran, Eray; Topkaya, CemThis paper describes an experimental study on European channel shear connectors. While shear studs are widely used in steel-concrete composite elements, the channel connectors are also gaining popularity due to their certain advantages. The channel connectors do not require special equipment and standard welding procedures are adequate for attachment purposes. In addition, this type of connector offers higher amounts of shear resistance due to its high contact area with surrounding concrete. Although first studies date back to 1950s. little work has been done in the past to investigate their behavior. Majority of the work done to date was on channel connectors used in North America with a very limited parameter range. An experimental study consisting of 15 push-out tests was carried out to investigate the behavior of European type channel connectors with various heights and lengths. The ultimate resistance of the connectors obtained from experiments was compared against those predicted by North American steel design specifications. It was observed that the equations presented in American and Canadian specifications are too conservative. Based on a model that represents the typical failure mechanism in push-out tests, a new equation was developed for the ultimate resistance of channel shear connectors. It is shown that the developed equation is capable of predicting the ultimate resistance of channel connectors with reasonable accuracy. (C) 2012 Elsevier Ltd. All rights reserved.Article Citation - WoS: 85Citation - Scopus: 104Effects of Cast-In Concrete Topping on Flexural Response of Precast Concrete Hollow-Core Slabs(Elsevier Sci Ltd, 2015) Baran, ErayResults of a study focusing on the flexural response of precast prestressed concrete hollow-core slabs with cast-in-place concrete topping are presented. The experimental part of the study included load testing of five precast concrete hollow-core units. The numerically determined flexural response of test specimens was later compared with the experimentally obtained behavior. Results demonstrate that a major composite action is valid between the hollow-core unit and the topping slab under load levels corresponding to uncracked state of the cross section. Existence of a topping slab resulted in improvements in the cracking moment and initial stiffness of hollow-core units. The beneficial effect of topping slab on the ultimate moment capacity was observed to be limited, mainly because of the loss of composite action prior to reaching the ultimate moment capacity. Horizontal shear strength at the interface between hollow-core unit and topping slab was determined (1) through limited number of pushoff load tests and (2) through calculations considering the load level corresponding to initiation of significant relative slip using the basic mechanics of materials approach and the simplified code expression. The measured and computed interface shear strength values were observed to be significantly lower than the horizontal shear strength values specified by the ACI and AASHTO Specifications. (C) 2015 Elsevier Ltd. All rights reserved.Article Citation - WoS: 49Citation - Scopus: 64Behavior of Cold-Formed Steel Wall Panels Under Monotonic Horizontal Loading(Elsevier Sci Ltd, 2012) Baran, Eray; Alica, CagatayThis paper summarizes the findings of an experimental study on cold-formed steel (CFS) wall panels with oriented strand board (OSB) sheathing. Static lateral load tests were conducted on a total of thirteen full-scale wall panel specimens to investigate the performance of CFS walls utilizing primarily the construction details used in Turkey. Experimental results revealed that the geometry of hold-down attachment used at the base of CFS wall panels to transfer tensile forces has a major effect on the overall behavior of the panels. Extensive damage was observed to occur in the hold-down attachment and in part of the bottom track adjacent to the hold-down, which prevented the wall panels to exhibit the stiffness associated with the main load resisting mechanisms. Tilting of the screws connecting the OSB sheathing to the CFS boundary framing members, as well as the separation of sheathing from the framing members were other commonly observed deformation modes. Existence of diagonal struts inside CFS frame was determined to cause a slight increase in load capacity and initial stiffness of the panels. It is also shown that the measured load capacity of wall panels can be predicted with an acceptable accuracy using design equations available in the literature. (C) 2012 Elsevier Ltd. All rights reserved.Article Citation - WoS: 31Citation - Scopus: 37Behavior of Steel-Concrete Partially Composite Beams With Channel Type Shear Connectors(Elsevier Sci Ltd, 2014) Baran, Eray; Topkaya, CemThis paper summarizes the findings of an experimental study investigating the flexural behavior of partially composite beams incorporating channel type shear connectors. Results from monotonic load testing of four full-scale steel-concrete composite beams and a steel beam are presented. The main effort focused on identifying the variation of strength and stiffness properties of beams with various degrees of partial composite action. Behavior of channel shear connectors in the composite beam specimens is related to those previously obtained from push-out tests of similar connectors. Finally, recommendations of the related AISC Specification on the strength and stiffness of composite beams are used for the assessment of the influence of the degree of partial composite action on flexural behavior. The experimental results revealed that even for beams with relatively low degree of partial composite action, major improvement on moment capacity and stiffness was obtained as compared to the steel specimen. The measured moment capacity of both the partially composite and fully composite beams agreed acceptably with the calculated capacities. The effective moment of inertia and the lower bound moment of inertia as specified by the AISC Specification were observed to overestimate the measured flexural stiffness of beams for all degrees of partial composite action investigated. (C) 2014 Elsevier Ltd. All rights reserved.Article Citation - WoS: 38Citation - Scopus: 43Experimental and Numerical Analysis of a Bolted Connection in Steel Transmission Towers(Elsevier Sci Ltd, 2016) Baran, Eray; Akis, Toga; Sen, Gokmen; Draisawi, AmmarThis paper presents an integrated numerical and experimental study on a bolted splice connection used in main legs of steel lattice transmission towers. At specific locations, where the number of angle sections in built-up cross section of main leg members changes, the complex geometry around the connection region results in eccentricities in the load path and indirect load transfer. Such complex configurations and uncertainties in the load path have led to overdesigned connections with increased number of bolts and redundant connection reinforcing members. The current study was conducted in an attempt to gain a better understanding of the load-flow mechanism at this specific location where the cross section of main leg members changes. The experimental part included tensile load testing of six specimens with different connection details. The main parameters used in the testing program were the number of bolts used in the connection as well as the presence of connection reinforcement angles and tie plate. For all connection configurations studied, the failure occurred due to net section fracture of upper main member angle near leading bolt holes. The calculated load capacity based on the measured material strength closely predicted the measured load capacity of specimens. The experimentally determined response of each connection configuration was better predicted by the FE model that incorporates bolt slip as compared to the model that assumes no slip. The experimental and numerical results also indicate that major differences among the investigated connection details do not cause any appreciable difference in behavior under tensile loading. (C) 2016 Elsevier Ltd. All rights reserved.
