• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.1
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• pp.54-64
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• 2007

This study is a fundamental research in order to establish the design code of recycled aggregate concrete structure. The structural properties of recycled aggregate concrete such as flexure, shear, fatigue, compression, and bond development are experimentally investigated and confirmed. In this study, laboratory-scale reinforced concrete beam, column, and pull-out test specimens using recycled coarse aggregate are manufactured. Then, the structural performances of recycled aggregate concrete according to replacement ratios of recycled coarse aggregate are evaluated. Also, finite element analysis using commercial code DIANA is carried out to predict the test results and the analysis results are compared with test results in this study. Structural test results showed that the structural performances of recycled aggregate concrete specimens with 60% replacement ratio are reduced by approximately 15-20%. These results indicated that the replacement ratio of recycled coarse aggregate within 30% is a suitable to use for structural members. The results of finite element analysis showed that the specimens with 30% replacement ratio possessed similar or more excellent structural performance than normal concrete specimens. However, recycled aggregate concrete with 60% replacement ratio of recycled coarse aggregate must be carefully considered for structural applications due to significant decrease of the failure loads.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.04a
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• pp.7-12
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• 1994

In structural analysis of prestressed concrete continuous flexural mambers, secondary effects produced by tendon forces should be reasonably estimated. The secondary moment at service load stags is normally used for ultimate required moment caculation in strength design. This concept has to be reviewed when precise analysis is performed considering construction step, time dependent properties of concrete and tendon. An ultimate moment computation proposed, concept and structural behavior. The previously proposed procedure by other researcher and the proposed procedure are compared and reviewed for the currently constructed precast prestressed concrete bridge.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1989.10a
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• pp.15-18
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• 1989

The planar effects on the concrete pavements Is mainly due to the concrete shrinkage, subgrade friction, and thermal expansion or contraction. A complete understanding of analytical behavior of concrete pavement requires the development of computer model, stiffness matrix and equivalent nodal load matrices due to the effects mentioned above. A computer program, INPLANE II, has been written to evaluate the planar effects on concrete pavements. The planar effects determine to what degree the joint open and also help In determining factors which affect the joint stiffnesses and structural behavior of concrete Pavements.

• Journal of Korean Association for Spatial Structures
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• v.20 no.3
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• pp.35-42
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• 2020

The purpose of this study is to develop precast concrete modules that can be used as a booth and a single-story building with a large space. This precast concrete module is originally designed to have a hexagonal facade when the upper and lower parts, which are symmetrical about horizontal connection line, are combined. A structural design was conducted to ensure structural safety of these precast concrete modules and to extend the slope of the inclined members as far as possible. Then the finite element analysis was performed to estimate the lateral and vertical deflection of complete precast concrete modular structures. And to verify the structural safety of these precast concrete modules, weight loading tests were conducted on the upper and lower modules respectively.

• Computers and Concrete
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• v.5 no.3
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• pp.261-277
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• 2008

This paper presents methodologies for remaining life prediction of plain concrete structural components considering tension softening effect. Non-linear fracture mechanics principles (NLFM) have been used for crack growth analysis and remaining life prediction. Various tension softening models such as linear, bi-linear, tri-linear, exponential and power curve have been presented with appropriate expressions. A methodology to account for tension softening effects in the computation of SIF and remaining life prediction of concrete structural components has been presented. The tension softening effects has been represented by using any one of the models mentioned above. Numerical studies have been conducted on three point bending concrete structural component under constant amplitude loading. Remaining life has been predicted for different loading cases and for various tension softening models. The predicted values have been compared with the corresponding experimental observations. It is observed that the predicted life using bi-linear model and power curve model is in close agreement with the experimental values. Parametric studies on remaining life prediction have also been conducted by using modified bilinear model. A suitable value for constant of modified bilinear model is suggested based on parametric studies.

• International Journal of Concrete Structures and Materials
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• v.10 no.2
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• pp.125-142
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• 2016

An overall review of the structural behaviors of ultra-high-performance fiber-reinforced concrete (UHPFRC) elements subjected to various loading conditions needs to be conducted to prevent duplicate research and to promote its practical applications. Thus, in this study, the behavior of various UHPFRC structures under different loading conditions, such as flexure, shear, torsion, and high-rate loads (impacts and blasts), were synthetically reviewed. In addition, the bond performance between UHPFRC and reinforcements, which is fundamental information for the structural performance of reinforced concrete structures, was investigated. The most widely used international recommendations for structural design with UHPFRC throughout the world (AFGC-SETRA and JSCE) were specifically introduced in terms of material models and flexural and shear design. Lastly, examples of practical applications of UHPFRC for both architectural and civil structures were examined.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.32-36
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• 2002

This paper presents the structural characteristic analysis of a centerless grinding machine with concrete bed. The centerless grinding machine is composed of grinding wheel head, regulating wheel head, concrete bed, wheel dresser and so on. Especially, the concrete bed is introduced to improve the static, dynamic and thermal characteristics of the centerless grinding machine. The structural analysis model of centerless grinding machine is constructed by the finite element method, and the structural characteristics in the design stage are estimated based on the structural deformation and harmonic response under the various testing conditions related to gravity force and directional farces

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.29-32
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• 2006

Different from new or reconstruction of an apartment housing, the structural safety in the remodelling construction can be obtained through the repair and strengthening process based on the safety diagnosis and evaluation of structural performance. In this study, structural performance of existing members such as, reinforced concrete slabs, beams and columns are investigated through experimental tests. The structural members were obtained from the existing apartment housing which will be demolished. Test results showed that most specimens have a sufficient structural capacity except for some special case, for example, specimens with severe cracks or concrete loss due to improper casting. This same severe deteriorated or defective structure members originated from bad concrete casting or careless construction process should be repaired and strengthened before an remodelling construction.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.501-504
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• 1999

Recently, composite structural systems have been developed actively due to its structural advantages of combining different materials. The objective of this paper is to investigate the structural behavior of moment connection in composite structures which consist of steel beams and reinforced concrete columns. In this study, three 1/2 scale joint specimens were tested under reversal loads. The results showed that beam-column joints maintain ductility, strength and exhibit excellent energy-dissipating capacity when subjected to inelastic deformations under reversal load.

• Journal of the Korea Concrete Institute
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• v.23 no.5
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• pp.637-645
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• 2011

It is well known that high strength concrete with compressive strength higher than 50 MPa shows severe material and structural damages under fire due to spalling. To understand degradation of structural capacity of fire damaged high strength concrete structures, not only thermo-mechanical behavior needs to be defined, but also structural behavior of high strength concrete member under high temperature needs to be investigated. In this study, structural tests are performed by applying axial loads on high strength concrete columns exposed at elevated temperatures for assigned amount of time. The tested columns are prepared to have different concrete strength and polypropylene fiber percentage. The test results show that structural capacity of the columns decreased with increased compressive strength of concrete under same heating condition. Especially, it is interesting to note that high strength concrete columns with polypropylene fiber for spalling proof did not improve structural capacity compared to the columns without polypropylene fiber. The findings from the test are able to improve fire proof design of high strength concrete structural members and predicting structural performance of fire damaged structural members.