• Composites Research
• /
• v.26 no.1
• /
• pp.66-71
• /
• 2013

As a fundamental structural element of construction, a pile is constructed to transfer loads from superstructure to foundation. In general, since the pile foundation is constructed in the ground or ground under water, it is difficult to protect from the damages due to moisture and/or salt which create corrosive environment and it is even more difficult to estimate its durability. In this study, in order to enhance the durability and constructibility of the pile foundation, FRP-concrete hybrid composite pile (HCFFT) is suggested. Moreover, equation for the prediction of load carrying capacity of HCFFT circular members under compression is suggested and discussed based on the results of analytical and experimental investigations. In addition, we also conducted the finite element simulation for the structural behavior of new HCFFT composite pile and the result is compared with those of experimental and analytical studies. In addition, the axial loading capacity of new HCFFT composite pile is compared with those of existing PHC pile and hollow circular steel pipe pile, and it was found that the new HCFFT composite pile has advantages over conventional PHC and steel pipe piles.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.03b
• /
• pp.34-34
• /
• 2010

This paper describes effect of the bending deformation of high voltage composite bushing with winding tension. The composite bushing can be formed, by adding silicone rubber sheds to a tube of composite materials. The FRP tube is internal insulating part of a composite bushing and is designed to ensure the mechanical characteristics. Generally the properties of FRP tube can be influenced by the winding angle, wall thickness and winding tension. As winding tension is increased glass contents was increased in the range of 70.4~76.6%. In the bending test, winding tension is increased residual deflection was decreased in the range of 14.0~12.2 mm.

• Journal of the Korea Concrete Institute
• /
• v.15 no.1
• /
• pp.143-153
• /
• 2003

New strengthening method based on Near Surface Mounted technique (NSM) is suggested, which can overcome the brittle nature of failure inherent to those reinforced concrete beams strengthened with FRP composite materials. The suggested technique secures ductile failure of reinforced concrete beams by having the strengthening Hybrid FRP rebars unbonded in parts. Experiments were performed in order to compare structural behaviors of strengthened beams with and without unbending along the Hybrid FRP rebars. Test results showed that only those beams strengthened by partially unbonded NSM failed in ductile manner. Theoretical expressions were derived for the minimum unbonded length of Hybrid FRP rebars with which ultimate strength of the reinforced concrete beam with partially unbonded NSM could be reached. The suggested partially unbonded NSM technique is expected to significantly improve the structural behavior of the strengthened beam with FRP composite materials.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.52 no.5
• /
• pp.69-76
• /
• 2010

The structural material with the highest possibility of new materials that will be used in the future construction field is fiber reinforced polymer. The current studies on FRP members by using such excellent material characteristics mostly focused on stability, composite problem, and durability of FRP members. The initially constructed FRP members secure excellent stability and durability compared to reinforced concrete and steel materials, but measures for defections during the periodical inspection, methods for detecting breakages, and maintenance and reinforcement are not insufficient. Accordingly, this study proposed a measurement system using the FRP sensor to evaluate the safety of the FRP modular box member, and applied the phased array ultrasonic technique to detect the defects and damage likely to occur during the performance period.

• Computers and Concrete
• /
• v.17 no.2
• /
• pp.215-225
• /
• 2016

High performance materials such as Fiber Reinforced Plastic (FRP) are often used for retrofitting structures against blast loads due to its ductility and strength. The effectiveness of retrofit materials needs to be precisely evaluated for the retrofitting design based on the dynamic material responses under blast loads. In this study, the blast resistance of Carbon Fiber Reinforced Plastic (CFRP) and Kevlar/Glass hybrid fabric (K/G) retrofitted reinforced concrete (RC) wall is analyzed by using the explicit analysis code LS-DYNA, which accommodates the high-strain rate dependent material models. Also, the retrofit effectiveness of FRP fabrics is evaluated by comparing the analysis results for non-retrofitted and retrofitted walls. The verification of the analysis is performed through comparisons with the previous experimental results.

• The Korean Journal of Ceramics
• /
• v.6 no.3
• /
• pp.201-205
• /
• 2000

Fiber reinforced plastic (FRP) composites and ceramic matrix composites (CMC) which contain electrically conductive phases have been designed and fabricated to introduce the detection capability of damage/fracture detection into these materials. The composites were made electrically conductive by adding carbon and TiN particles into FRP and CMC, respectively. The resistance of the conductive FRP containing carbon particles showed almost linear response to strain and high sensitivity over a wide range of strains. After each load-unload cycle the FRP retained a residual resistance, which increased with applied maximum stress or strain. The FRP with carbon particles embedded in cement (mortar) specimens enabled micro-crack formation and propagation in the mortar to be detected in situ. The CMC materials exhibited not only sensitive response to the applied strain but also an increase in resistance with increasing number of load-unload cycles during cyclic load testing. These results show that it is possible to use these composites to detect and/or fracture in structural materials, which are required to monitor the healthiness or safety in industrial applications and public constructions.

• Electrical & Electronic Materials
• /
• v.10 no.1
• /
• pp.45-53
• /
• 1997

The purpose of this paper is to evaluate FRP rod for aging, which exposed to salt water and pure at elevated temperature. Dielectric constant and tan .delta. on time and frequency domain were tested to observe how rapidly the FRP rod aged. Dielectric constants of FRP rods with treating time were slightly increased. That of FRP rods with frequency, However, showed strongly the effects of large relaxation time estimated from interfacial polarization a or ionic. It is obvious that absorbed water affects to dielectric and electric properties of FRP with increasing the treating time.

• Composites Research
• /
• v.19 no.2
• /
• pp.35-41
• /
• 2006

FRPs have been used widely and demonstrated in the field of aero industries etc., and began to be used as new construction materials of civil structures. Pre-stressing tendons, reinforcing bars etc. are all examples of the many diverse applications of FRP in new structures. Especially, 40 of all-FRP bridges were reported. The reason why FRP composites were used fur construction materials of civil structures, has been that the working time and the cost of maintenance can be reduced because of the effect of their lightness and durabilities. The purpose of this paper is to report the examples of the many diverse applications of Fiber Reinforced Plastic in construction materials of civil structures.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.7
• /
• pp.3280-3286
• /
• 2011

In recent years, many efforts have steadily been allocated to develop a new deck system in terms of its materials and structures in order to make up for the shortcomings of reinforced concrete deck. This study implemented and analyzed the verification for concrete composite beam with perfobond FRP as a permanent formwork and the tensile reinforcement, using non-linear finite element analysis program. Approximately 8-15% difference of ultimate failure load between numerical and experimental results were found and showed a similar figure of strain distribution in failure state.

• Composites Research
• /
• v.21 no.5
• /
• pp.1-8
• /
• 2008

In recent years, the reversed L-shaped perforated shear connector has been developed to mitigate the problem associated with headed stud and Perforbond shear connector and to simulate the simultaneous failure of concrete and shear connector. And FRP perforated shear connector has been applied to composite concrete and FRP module in the FRP-concrete composite bridge deck. The design criterion of the reversed L-shaped and FRP perforated shear connector has not been established yet since the lack of experimental and analytical study results. In this paper, the existing design equations for the Perforated were briefly discussed and the equation fur the prediction of shear resisting capacity of the reversed L-shaped and FRP perforated shear connector was suggested based on the experimental test, FEM analysis. and the existing equation for the Perfobond. The predict results obtained by the suggested equation arc compared with the experimental results, the applicability and effectiveness of suggested equation was verified.