• International Journal of Highway Engineering
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• v.6 no.1 s.19
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• pp.13-23
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• 2004

This paper presents the results of a study that was performed to evaluate structural behaviors and related distress of asphalt pavements on concrete bridge deck based on the visual inspection and 3-dimensional finite element analysis. As a result, three most failure types were found such as permanent deformation, potholes, and fatigue crackings. In addition, the failure mechanisms of different types of concrete bridge deck were investigated. An increase in fatigue of asphalt pavements on concrete bridge deck was observed and confirmed by the results from the visual inspections. In consequence, the aging and stripping of asphalt surfacing materials are relatively dominant factors on fatigue rather than traffic loadings.

• Magazine of the Korea Concrete Institute
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• v.11 no.2
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• pp.105-113
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• 1999

This study was conducted to evaluate the structural behaviors of Aramid fiber sheet reinforced slabs. Seven concrete slabs with $45{\times}8.5{\times}200cm$ were made for this experiment one slab with out being reinforced completely loaded until failure and the maximum load was obtained from this test. 70% of the maximum load was applied to 3 Aramid fiber sheet reinforced slabs after cracking and to the rest of 3 Aramid fiber sheet reinforced slabs without loading and cracking. Test results shows that maximum loading flexural rigidity and ductility for the Araimid fiber sheet reinforced slabs after initial cracking are similar as those for the Armied fiber sheet reinforced slabs without loading and cracking.

• Journal of the Korea Concrete Institute
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• v.28 no.5
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• pp.571-579
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• 2016

RS-LMC (Rapid Setting Latex Modified Concrete) has been widely used as repair material for bridge deck overlay or rehabilitation, because the overlaid pavement could be opened to the traffic after 3 hours of curing. Although the field performance of RS-LMC generally indicates that it has an excellent bonding to the substrate and shows a long term performance, the crack by vibration of vehicles have been happened on the overlay of bridges in technical reports. In this study, experimental research was carried out to evaluate the vibration properties of RS-LMC overlays by using P.S.T (Pavement Shaking Table). Total 12 specimens were tested and the variables are Latex-cement ratio (L/C) and amplitude of vibration. The result shows that the number of cracks and the total length of cracks are reduced as the increase of Latex-cement ratio (L/C) until 15%. And the crack occurs at a very small strain than the proposed values by Walter, D, G and design codes.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.1065-1068
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• 2008

Marine bridges are readily deteriorated due to the exposure to marine environment. The concrete deterioration occurred by corrosion of steel in concrete is mainly relevant to chloride in seawater. Chloride ions penetrate through porous concrete, and then reach to the reinforcing steel, and finally corroded them. The corrosion by-products(rusts) increase the volume as much as 6 to 10 times of origin steel. this creates expanding pressure and tensile stress, which cause the structures cracking and spalling. Sometimes the rebar corrosion is accelerated, and then collapsed catastrophically. In order to prevent corrosion damage, it is important to understand well regarding the reason of concrete corrosion, the quantification of its damage, and protection method/system to stop or to mitigate the corrosion. In this study, slab specimens were fabricated to evaluate the effect of cathodic protection which was simulated to marine bridges, and/or port structures. Zn-mesh sacrificial anode has been applied as a chathodic protection system and accelerated test conditions, i.e. temperature and salt concentration have been used in this study.

• Magazine of the Korea Concrete Institute
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• v.6 no.3
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• pp.152-161
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• 1994

Most widened bridges have been constructed by the joining-construction method that makes new and existing bridges structurally a single structure. Since the joining-construction method has several problems in design and construction viewpoint, this study is conducted in order to investigate the structural behaviors of RC slabs, which are widened and influenced by traffic-induced vibration of existing bridge during placing and curing of new concrete, with the prototype flexural strength test and FEM analysis. It was found that cracks are generated in construction joint at low applied load and that stress concentration at the joints and slips between steel bar and concrete are occured. But, the decreasing of load carrying capacity is negligible according to the traffic-induced vibration as well as the difference of construction method.

• Journal of Korean Society of Steel Construction
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• v.9 no.3 s.32
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• pp.351-362
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• 1997

In designing short to medium-span bridges, continuous composite bridges are becoming popular due to their advantages. However, if the concrete slab in continuous composite bridge is not prestressed, negative moment occurs in the mid-support and creates problems such as cracks in the concrete slab. Therefore. it must be considered in design. Two methods of arrangement of shear connectors were conducted using finite element elastic plastic analysis. Partial interaction theory was introduced and an analytical solution based on this theory was derived. The differences in the degree of interaction were investigated using analytical solutions and finite element analyses of simple composite beam and continuous composite beams. The results of the analyses were used to determine the advantage and disadvantages as well as any precaution when necessary using partial composite during actual design and construction.

• International Journal of Highway Engineering
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• v.11 no.3
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• pp.1-11
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• 2009

This study focuses on evaluating the applicability of an acryl based polymer concrete to the thin bridge deck pavements. The acryl concrete developed in this study is composed of Methyl Methacrylate(MMA) resin, benzol peroxide and fillers. To study the effects of the types and amounts of the components on the physical characteristics of the acryl concrete, viscosity, compressive strength and bending tests were conducted. The optimum mixture design was then determined based on the testing results. Several different types of laboratory tests, such as water and chlorine ion penetration tests, shrinkage and thermal coefficients tests, and tensile bonding strength tests were performed for the optimum acryl concrete and conventional cement concrete. The testing results show that water and chroline ion resistance, bonding strength between acryl and cement concrete and crack resistance of the acryl concrete is better than those of the conventional cement concrete. There are shortcomings that the conventional acryl concrete has a higher shrinkage and thermal coefficients. However, it was confirmed that to use newly developed rubberized MMA resin in this study reduces the crack resistance with substantially increased ductility.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.303-310
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• 2021

Cracks in bridges are important factors that indicate the condition of bridges and should be monitored periodically. However, a visual inspection conducted by a human expert has problems in cost, time, and reliability. Therefore, in recent years, researches to apply a deep learning model are started to be conducted. Deep learning requires sufficient data on the situations to be predicted, but bridge crack data is relatively difficult to obtain. In particular, it is difficult to collect a large amount of crack data in a specific situation because the shape of bridge cracks may vary depending on the bridge's design, location, and construction method. This study developed a crack detection model that generates and trains insufficient crack data through a Generative Adversarial Network. GAN successfully generated data statistically similar to the given crack data, and accordingly, crack detection was possible with about 3% higher accuracy when using the generated image than when the generated image was not used. This approach is expected to effectively improve the performance of the detection model as it is applied when crack detection on bridges is required, though there is not enough data, also when there is relatively little or much data f or one class.

• Journal of the Korea Concrete Institute
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• v.20 no.4
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• pp.423-430
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• 2008

VES-LMC (very-early strength latex-modified concrete) has been widely used as repair material for bridge deck overlay or rehabilitation, because the overlaid or repaired could be opened to the traffic after 3 hours of curing. Although the field performance of VES-LMC generally indicates that it has an excellent bonding to the substrate and shows a long term performance, little quantitative data or research results have been presented in the literature on structural studies. The purpose of this study was to investigate the flexural behavior, interfacial performance, crack propagation, and strengthen effect of RC beam overlaid or repaired by VES-LMC through the 4-point flexural loading test. Two different types of RC beam were fabricated for repair and rehabilitation types. The test result showed that the strengthen effect, in term of flexural stiffness, increases as the depth of repair or overlay increases. More than 40% of stiffness was improved when the depth of repair was up to steel position. However, there was a little difference between 80 mm and 120 mm repaired beam. This means the repair depth must be considered. The interfacial behavior data showed that the repaired or overlaid beams had a little relative displacement. This means that two materials behave comparatively acting together. However, there were two specimens which had large displacement at the interface, because of poor bond strength. This suggested that interface treatment is one of the most important jobs in composite beams.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.1
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• pp.61-71
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• 2010

The attributes related to the health condition of RC deck slabs are analyzed to help us identify and rate the safety level of the bridges in this study. According to the related reports the state assessment for the outward aspects of bridges is the important and critical part for rating the overall structural safety. In this respect, the careful identification for the various state attributes make the field inspection and structural diagnosis very effective. This study analyzes the influence of the state attributes on evaluation classes and the relationship of them by the inductive reasoning, which raise the understanding and performance for evaluation work, and support the logical approach for the state assessment. ID3 algorithm applied to the case set which is constructed from the field reports indicates the main attributes and the precedence governing the assessment, and derives the decision hierarchy for the state assessment.