• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.350-355
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• 1994

This study is aimed at the experimental investigation of the influence of the structural parameters such as concrete cover, width of specimen and bar size on the dowel action of reinforcing bari in high strength concrete members. Based on the proper combination of these parameter, a total of 46 specimens has been cast for fc'= 500 ㎏/㎠ and another 46 specimens for fc'= 700 ㎏/㎠, and cured at the laboratory. Comparative analyses have been made for the parametric contribution to the dowel strength from the test results, and a regress equation has been suggested.

• Journal of Korean Society of Steel Construction
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• v.20 no.5
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• pp.665-673
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• 2008

The composite structures of steel and reinforced concrete, which have been widely used in large-scale concrete structures, werestudied to investigate the cause of unexpected cracks and to verify the composite actions between the two materials. Vertical stiffeners between flanges, studs and dowel bars, stirrups, and concrete strength were chosen as experimental variables in afour-point loading test. The results showed that the vertical stiffener prevented not only the local web buckling, but also bond failures between steel and concrete. It increased the flexural resistance (fracture loads) due to the composite action of two materials, compared withthose of any experimental variable. However, the composite behavior of steel reinforced concrete beam was not affected seriously by additional studs, dowel bars, stirrups, and concrete strength.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2838-2843
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• 2011

Recently, the floating slab track that can effectively mitigate the vibration and structure-borne noise is being discussed to be adopted. The floating slab track which is a track system isolated from the sub-structure by vibration isolators. Unsimilarly to conventional track and the slab deflection is large. Therefore, the running safety and ride comfort should be investigated. Especially at slab joint since the load cannot be transferred, the possibility that the dynamic behavior of track and train became unstable is high. Thus, in general dowel bar are often installed at slab joints. To determine the appropriate dowel ratio the load transfer characteristics should be investigated. In this study, dowel bar joint is modeled by equivalent shear spring and this model is verified by comparison with experimental results. Using the proven model, the load transfer efficiency and deflection at slab joint according to dowel ratio, and stiffness and spacing of vibration isolator were examined.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.375-381
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• 2011

The passage of railway vehicles generates mechanical vibrations and noises. This problem can be mitigated by the 'floating slab track' that isolating from infrastructures by installing vibration isolator in the concrete slab track. In the previous researches, adjacent floating slab tracks are connected by dowel bar system. It has been reported that many dowel bars with less diameter show better load transfer efficiency (LTE) compared to small number of dowel bars with larger diameter under the condition of the same dowel area. In this study, dowel system is further considered as a concrete anchorage system and the design strength of the dowel system was evaluated based on ACI code 318-08 Appendix D. The design strength of dowel system is then verified against failure load test of floating slab system.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.04a
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• pp.59-64
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• 1994

Following the previous research(7), a total of forty six specimens were tested to scrutinize the dowel action of reinforcing bars. Concrete cover, width of specimen and reinforcing bar size were taken as main test variables for constant compressive strength of concrete, based on the observation of the test results, the characteristic effects of the test variables on the dowel strength have been analyzed.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.250-255
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• 1993

This research is aimed at the experimental investigation of the characteristic contribution of the structural parameters, such as concrete over, concrete strength and reinforcing bar size on the dowel strength of the reinforced concrete stuctures. A total of twenty four specimens were tested for eight experimental conditions. The test results showed relatively close agreements with the values calculated by Vintzeleou-tassios equation. From the observations of the test results, it was found that the concrete cover affected almost linearly on the dowel strength , while the var size and the concrete strength showed coupled effects.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.325-330
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• 2008

This study carried out the repeated freezing-thawing test in order to understand the long-term degradation mechanism of GFRP dowel bars. The mechanical property measured by shear test. In addition, analyzes repeated freezing-thawing degradation mechanism of GFRP dowel bars by observe the microstructure through Scanning Electron Microscope (SEM) and Gas Physisorption techniques. As the result of test, it was found that the mechanical property didn't decreased as the exposure time to water and repeated freezing-thawing environment. It shows clearly observed microstructure investigations.

• Journal of Korean Association for Spatial Structures
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• v.20 no.4
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• pp.123-130
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• 2020

Generally the non-bearing walls in apartment buildings in Korea are not considered as a lateral force resisting members for the design consideration. This engineering practice caused large crack damages and brittle fractures of the non-bearing walls when subjected to Pohang earthquakes in 2017 since those have not been designed for seismic loading. In this study, finite element analysis was conducted for slot type non-bearing wall connection system to reduce damages and concentrate damages to the designated damping device through separation from the structural wall members. Steel plate and dowel bar systems designed for the dissipation of seismic energies were modeled and analyzed to investigate the damage reductions. Finally, the test result and the analysis result were compared and verified.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.2125-2133
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• 2013

Recently, an interest on joint behavior between adjacent concrete slab tracks has increasing due to large application of such track system. Dowel bars are widely used to improve load transfer capacity across the joints. Dowel bars reduce the deflections and stresses by transferring the load between the slabs. This study proposes the lumped shear spring model to efficiently model dowel joints of adjacent slabs. This model includes bearing stiffness between dowel bar and concrete as well as dowel gap. Strength of the proposed spring model is evaluated based on Concrete Capacity Design method under the assumption of shear failure mode in the joints. Experiments are also performed up to failure to evaluate the accuracy of the proposed model. It has been observed that the proposed model is able to predict initial nonlinearity due to dowel gap, and capture material nonlinearity of the test slabs. Thus, it is recommended that the proposed model can be effectively applied to the dowel joints of concrete slab track.

• KCI Concrete Journal
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• v.12 no.2
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• pp.23-30
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• 2000

This paper presents behavior of concrete pavement at transverse joint subject to static test load. The test was conducted on 1/10 scale model in the laboratory. Load transfer across the crack is developed either by the interlocking action of the aggregate particles at the faces of the joint or by a combination of aggregate interlock and mechanical devices such as dowel bars. In this study, significant three variables considered to the performance of joints were selected. : (a)diameter of dowel bars(2.5mm, 3.0mm, 4.0mm), (b)presence or absence of dowel bars, (c)aggregate types(crushed stone, round stone). Experimental results were analyzed to find relationships among displacement of discontinuous plane at jointed slab, load transfer efficiency and joint opening, etc. Displacement of discontinuous plane at joint was decreased according to the increase of dowel bar diameter. In addition, it is found that model slabs made using crushed stone had better load transfer characteristics by aggregate interlock than model slabs made using similarly graded round stone. Displacement of discontinuous plane was increased according to the increase of loading. In addition, it was decreased as dowel diameter(2.5mm, 3.0mm, 4.0mm) was increased. In the case of slab without dowel bars, displacement of discontinuous plane was greatly increased and load transfer effciency of slab applied crushed stone was shown 30 percent greater than round stone. In addition, load transfer efficiency of slabs, which were made using crushed and round stone without dowel bars, was decreased to 20 percent and 30 percent, respectively as it was compared with slabs made us-ing dowel bars.