• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.11a
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• pp.183-188
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• 1999

Due to many advantages of advanced composite materials, research on the application of composites to the construction industry is initiated. In this paper, fabrication methods efficient for infrastructures and application examples of each method are discussed. It also presents the structural characteristics of concrete filled glass fiber reinforced composite tubular member. Experimental results shows that strength and ductility of composite compression member is considerably increased due to concrete confinement action of composite surface.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.04a
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• pp.176-183
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• 1995

The design process of pre-cast concrete member needs various design parameters and the engineer's experiences. The introduction of knowledge-based system in the design of pre-cast concrete member enables us to design complicated members using the designer's heuristics. The objectives of this research are to study useful methodology for representing knowledge and data in the development of knowledge-based system and to show the application of methodology by developing a prototype sysytem for design of pre-cast concrete member. This paper nrst describes methodology for building knowledge-based system. It then presents knowledge-based system for pre-cast concerete member design.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.115-120
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• 2000

Currently, in evaluating a flexural strength of a concrete member, the effect of specimen depth has not been systematically studied, even though its effect on ultimate strength of a section is very important. For all types of loading conditions, the trend is that the strength of a member tends to decrease when the member depth increases. In this study, the influence of specimen depth on flexural compressive strength of concrete member was examined experimentally. A series of C-shaped specimens subjected to axial compressive force and bending moment were tested using three geometrically similar specimens with different length-to-depth ratios(h/c=1, 2 and 4) which have compressive strength of 55MPa. The results indicate that the flexural compressive strength decreased as the specimen depth increased. A model equation was derived based on regression analyses of the experimental data. Also the results show that ultimate strain decreases as the specimen depth increases. Finally, a general model equation for the depth effect is proposed.

• Journal of the Korea Concrete Institute
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• v.12 no.5
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• pp.121-130
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• 2000

Currently, in evaluating a flexural strength of a concrete member, the effect of specimen depth has not been systematically studied, even though its effect on ultimate strength of a section is very important. For all types of loading conditions, the trend is that the strength of a member tends to decrease when the member depth increases. In this study, the influence of specimen depth on flexural compressive strength of concrete member was examined experimentally. A series of C-shaped specimens subjected to axial compressive force and bending moment were tested using three geometrically similar specimens with different length-to depth ratios (h/c = 1, 2 and 4) which have compressive strength of 55 MPa. The results indicate that the flexural compressive strength decreased as the specimen depth increased. A model equation was derived based on regression analyses of the experimental data. Also, the results show that ultimate strain decreases as the specimen depth increases. Finally, a general model equation for the depth effect is proposed.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.181-188
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• 2001

Due to many advantage of advanced composite material, research on the composite compression member is initiated. In this paper structural characteristics of concrete filled glass fiber reinforced composite tubular member is studied. Through 4-point flexural test with various level of axial force, the performance of composite compression member was analyzed. Also numerical method to find P-M diagram of composite compression member was developed. It is demonstrated that result of numerical method agree well with experimental results.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.17-20
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• 2005

This study investigates mock-up test of the concrete containing crushed sands with improved quality and following could be draws as conclusions. The slump satisfies the target value. The air content reaches the goal, however, it decreases by the occurrence of loss with elagse of age. In normal strength region, the setting time of CS24 member is shorter than that of SS24 member. In high strength region, the setting time of SS50 member is make only slower than that of CS5O because of the use of retarding AE agent. The compressive strength of the concrete using crushed sands is little higher than the concrete using washed sea sands, and the compressive strength of core sample increases at lower part. Drying shrinkage of the concrete using crushed sands is larger than that using washed sea sands. At water caring condition, both the concrete using crushed sands and using washed sands expand at first, exhibit to be swelled and with elagse of age, they remain relatirely constant. Also, the drying shrinkage occurred greatly when the width and thickness of a member are small because it is easy to evaporate the inner part vapor in the small width and thickness of a member. there can be little different according to the location of a contact gauge, however it is similar to the change of specimen's length change. The concrete using crushed sands, of which grading, grain shape and fine particle is improved, are comparable to the quality of the concrete using washed sea sand.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.315-320
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• 1998

The experimental set-up and one-dimensional analytical model have been developed to investigate the tensile behavior of reinforced concrete member due to restrained drying shrinkage. The experimental results have been compared with the analytical prediction of the maximum residual stress of steel and concrete due to restrained shrinkage. The tensile residual stress concrete by one-dimensional bilinear model shows 0.19 and 0.63 of tensile strength for 0.83% and 3.29 of steel ratio. The residual tensile stress of concrete increases as the steel ratio increases. The effect of steel fiber has not influenced the residual stress due to restrained shrinkage of concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.309-312
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• 2006

An experimental study for bond slip behavior of concrete and a FRP plank was used as the both formwork and the tensile reinforcement for a concrete structural member is described. For the FRP plank and the concrete to act as a composite structural member a satisfactory bond at the interface between the smooth surface of the FRP and the concrete must be developed. This study focuses on investigation of the bond slip behavior of sand coated interface between FRP and cast-in-place concrete experimentally.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.69-75
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• 2017

Structural safety evaluation for static strength of thin plate RC member with high strength concrete is conducted in this study. Static strengths were predicted and compared with the experimental values. Predicted values were calculated by the evaluation formula based on the punching shear behavior and the yield line theory which can appear in the plate members. Static load tests were carried out for the specimens with high strength concrete and the test results were compared with the required performance in design. The comparison results show that the specimens with high strength concrete have sufficient structural safety for flexural and punching shear performance required in design. High strength concrete specimens exhibited excellent strength despite their small thickness. The range of concrete strengths applied in this study was about 60 MPa to 100 MPa.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.126-133
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• 2005

Behavior of saw-dust concrete has not studied because many people have thought that saw-dust concrete cannot be applicable for structural member, up to now. This study is to findout how much the concrete can be structurally applicated. 5mm grid sieve was used to select satisfactory sawdust for better concrete quality. Test molds size of ${\phi}10{\times}20cm$ long were made of normal without sawdust, 0.05%, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8% 2.0%, for making concrete strengh of 180kg, 210kg, 240kg, 270kg which they are normally used in practice presently. A various strengths tests such as compressive splitting tensile, flexible strength behavior of structural member named beam using size of $20{\times}30{\times}120cm$ have been done for the structural aspects. Tensile strength shows that it can be more affected than higher strength of it.