The Experts below are selected from a list of 18 Experts worldwide ranked by ideXlab platform
Karin Lundgren - One of the best experts on this subject based on the ideXlab platform.
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lap splice over a grouted Joint in a lattice girder system
Magazine of Concrete Research, 2007Co-Authors: Karin LundgrenAbstract:Load-carrying in two directions in lattice girder slab systems by complementing with lapped reinforcement across the Joints at the construction site was studied. A detailing of load-carrying Joints without any reinforcement across the Cast Joint was considered. The behaviour of the Cast Joint between the preCast concrete and the in situ Cast concrete is very important. Two different surface treatments were tested in two types of detail tests of the Cast Joint: one type in which the Cast Joint was loaded in shear, and one in tension. Furthermore, the detailing of the Joint between two preCast concrete panels was tested in bending in full-scale tests. The detail tests were used to calibrate a friction model of the Cast Joint, which was then used in finite-element analyses (FEAs) of the full-scale tests. In the full-scale tests, the Joints were strong enough to carry the applied load; thus, the failure mode was rupture of the reinforcement in all full-scale tests, and only one crack occurred—in the in situ Cast concrete above the Joint between the preCast elements. However, the FEAs of the full-scale tests revealed that the detailing was sensitive to secondary cracking.
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lap splice in a lattice girder system
Proceedings Nordic Concrete Research Meeting, 2005Co-Authors: Karin LundgrenAbstract:A detailing of load-carrying Joints between lattice girder slabs without any reinforcement across the Cast Joint was studied. The behaviour and capacity of the Cast Joint between the preCast concrete and the in situ Cast concrete is very important for this detailing. Two types of detail tests of the Cast Joint were carried out: one type where the Cast Joint was loaded in shear and one in tension. Furthermore, the detailing of the Joint between two preCast concrete panels was tested in bending in full-scale tests. The detail tests were used to calibrate a model of the Cast Joint, which was then used in finite element analyses of the full-scale tests.
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analysis of a lap splice in a lattice girder system
2003Co-Authors: Karin LundgrenAbstract:To enable load-carrying in two directions in lattice girder systems, transverse reinforcement is needed. In the present study, the possibility to put transverse reinforcement in the preCast concrete panels and complement with lapped reinforcement across the Joints at the construction site was studied. The behaviour of such a Joint, when subjected to bending, was investigated in two-dimensional finite element analyses. The analyses show that the Cast Joint between the preCast concrete and the in-situ Cast concrete is the weak link in this detailing, as could be expected. In the analyses where a rather large amount of transverse reinforcement was used, o8 s150 NPs 700, the Joint could be loaded close to yielding of the reinforcement; then opening of the Cast Joint occurred in all of the analyses. When no bent reinforcement, crossing the Cast Joint, is present, the failure mode will most likely become brittle. It is therefore recommended to have bent reinforcement crossing the Cast Joint. Two analyses were carried out with two different placement of bent reinforcement, o8 s150 B500B in both cases. When the bent reinforcement was placed close to the Joint, it obtained large stresses rather early in the analysis, and the analysis became unstable for rather low rotations. When the bent reinforcement was placed further away from the Joint, the transverse reinforcement reached yielding, and the deformation capacity was approximately doubled compared to the other analyses. For small amounts of transverse reinforcement, or reinforcement with a lower yield strength, it might be possible to use the studied detailing even without bent reinforcement crossing the Joint. In one analysis where the transverse reinforcement had a reduced yield strength, 500 MPa instead of 700 MPa, the reinforcement reached yielding, and it was possible to keep the yielding moment some additional rotation before the Joint opened up. The modelling of the Cast Joint is of very large importance for the results of the analyses. The modelling of that was checked through analyses of Joints between preCast and in-situ concrete tested by Nissen et al. (1986), who made a large experimental investigation on the interaction between preCast and in-situ concrete. Still some uncertainty about the input parameters remain. Furthermore, long term effects such as shrinkage and creep were not included in these analyses. It is recommended to do further studies, including full-scale testing of lap splices before this detailing is used in practice.
Helmut Clemens - One of the best experts on this subject based on the ideXlab platform.
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characteristics of an optimized active metal Cast Joint between copper and c c
Physica Scripta, 2007Co-Authors: Betram Schedler, T Huber, T Friedrich, Elisabeth Eidenberger, Marlene Kapp, Christina Scheu, Reinhard Pippan, Helmut ClemensAbstract:In this paper, an optimized active metal Cast copper to carbon composite (C/C) Joint is examined. Mechanical characterization by means of shear and tensile tests as well as fracture toughness measurements at ambient temperature are employed, which show that the obtained values are above those of the reference Joint that has been used so far. The phases occurring at the interface region and the fracture surface of the optimized Joint are investigated in detail to explain the improved mechanical behaviour. The composition and the morphology at the interface region are analysed by means of scanning electron microscopy. In addition, the crack path is analysed by stereomicroscopy. The improved properties can be explained by the circumstance that the fracture of the optimized Joint is not restricted to the interface between the occurring carbide and the C/C but changes between C/C, the carbide to C/C interface and the copper, depending on the local structure in the C/C composite.
Betram Schedler - One of the best experts on this subject based on the ideXlab platform.
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characteristics of an optimized active metal Cast Joint between copper and c c
Physica Scripta, 2007Co-Authors: Betram Schedler, T Huber, T Friedrich, Elisabeth Eidenberger, Marlene Kapp, Christina Scheu, Reinhard Pippan, Helmut ClemensAbstract:In this paper, an optimized active metal Cast copper to carbon composite (C/C) Joint is examined. Mechanical characterization by means of shear and tensile tests as well as fracture toughness measurements at ambient temperature are employed, which show that the obtained values are above those of the reference Joint that has been used so far. The phases occurring at the interface region and the fracture surface of the optimized Joint are investigated in detail to explain the improved mechanical behaviour. The composition and the morphology at the interface region are analysed by means of scanning electron microscopy. In addition, the crack path is analysed by stereomicroscopy. The improved properties can be explained by the circumstance that the fracture of the optimized Joint is not restricted to the interface between the occurring carbide and the C/C but changes between C/C, the carbide to C/C interface and the copper, depending on the local structure in the C/C composite.
T Huber - One of the best experts on this subject based on the ideXlab platform.
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characteristics of an optimized active metal Cast Joint between copper and c c
Physica Scripta, 2007Co-Authors: Betram Schedler, T Huber, T Friedrich, Elisabeth Eidenberger, Marlene Kapp, Christina Scheu, Reinhard Pippan, Helmut ClemensAbstract:In this paper, an optimized active metal Cast copper to carbon composite (C/C) Joint is examined. Mechanical characterization by means of shear and tensile tests as well as fracture toughness measurements at ambient temperature are employed, which show that the obtained values are above those of the reference Joint that has been used so far. The phases occurring at the interface region and the fracture surface of the optimized Joint are investigated in detail to explain the improved mechanical behaviour. The composition and the morphology at the interface region are analysed by means of scanning electron microscopy. In addition, the crack path is analysed by stereomicroscopy. The improved properties can be explained by the circumstance that the fracture of the optimized Joint is not restricted to the interface between the occurring carbide and the C/C but changes between C/C, the carbide to C/C interface and the copper, depending on the local structure in the C/C composite.
T Friedrich - One of the best experts on this subject based on the ideXlab platform.
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characteristics of an optimized active metal Cast Joint between copper and c c
Physica Scripta, 2007Co-Authors: Betram Schedler, T Huber, T Friedrich, Elisabeth Eidenberger, Marlene Kapp, Christina Scheu, Reinhard Pippan, Helmut ClemensAbstract:In this paper, an optimized active metal Cast copper to carbon composite (C/C) Joint is examined. Mechanical characterization by means of shear and tensile tests as well as fracture toughness measurements at ambient temperature are employed, which show that the obtained values are above those of the reference Joint that has been used so far. The phases occurring at the interface region and the fracture surface of the optimized Joint are investigated in detail to explain the improved mechanical behaviour. The composition and the morphology at the interface region are analysed by means of scanning electron microscopy. In addition, the crack path is analysed by stereomicroscopy. The improved properties can be explained by the circumstance that the fracture of the optimized Joint is not restricted to the interface between the occurring carbide and the C/C but changes between C/C, the carbide to C/C interface and the copper, depending on the local structure in the C/C composite.