In recent days composite bridge decks are increasingly used to new and rehabilitated bridges due to their many advantages such as light weight, high strength, high durability, low maintenance costs and fast installation. To further promote usage of composite bridge decks, the authors have developed decks of new profile having innovative vertical snap-fit connection. Through this development, significant enhancement of constructability and economy are obtained by overcoming the drawbacks of conventional composite decks of tongue-and-groove connection. The paper introduces some research results and notable applications for the developed composite decks of snap-fit connection using for pedestrian bridges. Owing to their considerable advantages of the developed composite decks, increasing number of applications is currently underway in Korea.

This study is for reduction of heat island to control the rise in climate, temperature changes, according to the passage of a vehicle due to cyclic loading, such as cracks in the asphalt layer in order to determine the proper diameter control and caused the asphalt to prevent damage. Slab drain is suitable to determine drainage asphalt diameter.

This study carried out real car crash simulation of composite post structures for road facilities. The effects of different material properties of composites for various parameters are studied using the LS-DYNA finite element program for this study. In this study, the existing finite element analysis of steel post structures using the LS-DYNA program is further extended to study dynamic behaviors of the structures made of various composite materials. The numerical results for various parameters are verified by comparing different models with displacements and stress distribution occurred in the post and car.

This paper experimentally investigates the seismic performance of RC columns retrofitted by Super Reinforcement with Flexibility (SRF). A total of three specimens with a scale factor of 1/2 were constructed and tested in order to assess the structural behavior of the retrofitted RC columns. One specimen was a non-seismically designed column without any retrofitting method while others were retrofitted with either one or two layers of SRF by using urethane adhesive. The static cyclic testing with a constant axial load was conducted to assess the seismic performance of the retrofitted RC columns. It is concluded that the SRF retrofitting method increases the strength and ductility of the RC columns and can also impact on the failure mode of the columns.

It has been more than twenty years since the application of GFRP bridge decks in construction fields. Recently, a few studies by governments and individual researchers have investigated in-use GFRP bridge decks. Areas of trouble include the problems of cracking, spalling and the de-bonding of the pavement or the wearing surface on GFRP bridge decks, all of which affect the long-term durability and serviceability of these new construction materials. Related to these problems, reflective cracks on asphalt pavement are directly related to pultruded GFRP bridge decks. This study investigates the behavior of an adhesive joint under weak-axis bending by tests and FE analyses to identify the causes of pavement cracks in in-use pultruded GFRP bridge decks. In detail, the flexural stiffness and the load-carrying capacities in strong and weak axes are measured during bending tests on pultruded GFRP decks. Next, tensile local failures of an epoxy adhesive due to the concentration of deformations at adhesive joints are identified via a weak-axis bending test. Finally, the tensile failure of an epoxy adhesive due to the local concentration of deformation at an adhesive joint under weak-axis bending is verified through a finite element analysis.

The floating PV generation structure installed on the surface of water has been recently issued as a representative items for the low carbon and green growth campaign. Moreover, the studies and developments for the structure and construction improvements of floating PV generation structure have been in progress. For example, in the previous research, the floating PV generation structure consisted of pultruded FRP and SMC FRP members is suggested. In this study, we conduct the analytical and experimental studies for estimating the structural characteristics of SMC FRP vertical members. From the analytical and experimental results, it is found that SMC FRP vertical members used for floating PV generation structure have sufficient structural safety and stability.

Pultruded FRP can be regarded as an orthotropic material due to its manufacturing process that pull-out fibers impregnated with polymeric resin, which is suitable to produce structural member with unlimited lengths of reinforced polymer structural shapes with a various shape of cross-section. However, fiber distribution in the cross-section is not uniform because of the characteristics of pultrusion process. Therefore, random fiber distribution causes the difference of the modulus of elasticity throughout the cross-section. In this paper, closed-form local buckling analysis is conducted on the pultruded FRP I-shape compression members. The mechanical properties used to analytical investigations are obtained from the coupon test. The coupon test specimens are taken from the pultruded FRP I-shape member. Moreover, the local buckling tests of pultruded FRP I-shape members are conducted and test results are compared with the analytical results.

An orthotropic plastic constitutive model for fiber-reinforced composite material, is developed, which is simple and efficient to be implemented into computer program for a predictive analysis procedure of composite laminates. An orthotropic initial yield criterion, as well as work-hardening model and subsequent yield surface are established that includes the effects of different yield strengths in each material direction, and between tension and compression. The current model is implemented into a computer code, which is Predictive Analysis for Composite Structures (PACS). The accuracy and efficiency of the anisotropic plastic constitutive model and the computer program PACS are verified by solving a number of various fiber-reinforced composite laminates. The comparisons of the numerical results to the experimental and other numerical results available in the literature indicate the validity and efficiency of the developed model.

In this study, material characteristics of glass fiber composite were evaluated by experiment. Tensile, compression and in-plane shear test were performed as test method of ASTM. Velocity of Tensile and compression test was 2mm/min and in-plane shear test was 4mm/min. At the test result, elastic modulus of tensile and compressive were similar. Maximum compressive strength and maximum compressive strain were smaller than the maximum tensile strength and maximum tensile strain.

본 연구는 최근 세계적으로 이상기후에 의하여 빈번히 발생하는 지진재해에 의한 주요시설물 피해저감 및 신속복구에 대한 복합재료 적용에 관한 연구이다. 최근에 발생된 지진의 경우, 1차 지진에 의한 시설물 피해가 발생하고 이후 강력한 규모의 2차, 3차 여진이 지속적으로 발생하고 있다. 이에 대응하기 위하여 국외에서는 병원, 방송국 등과 같은 주요시설물의 초기 지진피해에 의한 피해와 손상을 신속히 응급복구하고 향후 2차 여진 및 관련 시설물에 대한 항구적인 보강대책을 제공할 수 있는 내진안전성 개선연구가 활발히 진행되고 있다. 본 논문에서 제시한 긴급복구용 파형강판-GFRP 내력패널의 경우, 강재료인 파형강판을 사이에 두고 외부를 GFRP 로 하여 GFRP-파형강판을 결합한 구조의 내력패널을 제작하여 기존 콘크리트 또는 강 프레임 구조물 내 지진에 의한 벽체손상 피해 발생 시 이들 손상된 벽체(조적조 또는 콘크리트 벽체)를 제거한 후 사전제작된 GFRP 내력벽 체를 적용, 대체 횡적 보강구조체로 시공하여 향후 피해저감 및 응급복구용으로 그 효율성을 극대화 및 내진 피해를 예방하고자 한다.

본 연구는 최근 세계적으로 이상기후에 의하여 빈번히 발생하는 지진재해에 의한 주요시설물 피해저감 및 신속복구에 대한 복합재료 적용에 관한 연구이다. 최근에 발생된 지진의 경우, 1차 지진에 의한 시설물 피해가 발생하고 이후 강력한 규모의 2차, 3차 여진이 지속적으로 발생하고 있다. 이에 대응하기 위하여 국외에서는 병원, 방송국 등과 같은 주요시설물의 초기 지진피해에 의한 피해와 손상을 신속히 응급복구하고 향후 2차 여진 및 관련 시설물에 대한 항구적인 보강대책을 제공할 수 있는 내진안전성 개선연구가 활발히 진행되고 있다. 본 논문에서 제시한 긴급복구용 GFRP 내력패널의 경우, 기존 콘크리트 또는 강 프레임 구조물 내 지진에 의한 벽체손상 피해 발생 시 이들 손상된 벽체(조적조 또는 콘크리트 벽체)를 제거한 후 사전제작된 GFRP 내력벽체를 적용, 대체 횡적 보강구조체로 시공하여 향후 피해저감 및 응급복구용으로 그 효율성을 극대화하고 예방하는 내진 공법을 개발하고자 한다.

Glass fiber reinforced thermosetting polymer plastic (GRP) is widely used in the construction industries due to the advantages of their superior mechanical and physical characteristics. Most of pipes are installed for long-term purposes and they should be safely installed in consideration of installation conditions because there are unexpected various terrestrial loading conditions. In this paper, we present the result of investigation for 253 days pertaining to the structural behavior of flexible pipes buried underground. From the buried test results, we predicted long-term, up to 60 years, ring deflection of GRP pipes buried underground based on the method suggested by the existing literature. It was found that the GRP flexible pipe is appropriate because 5% ring deflection limitation of 60 years could be satisfied.

Risers are often exposed to harsh ocean environments, and vulnerable to various damages. The riser failure may cause serious economical losses as well as environmental problems. Therefore, maintaining the structural integrity of the riser is very important. This paper deals with the methodology for monitoring structural integrity of the riser using dynamic characteristic changes such as mode shapes. The damage index method, which has been proved its usefulness in many applications, is applied to a numerical study to test its feasibility of identifying damage in a riser. The numerical study is performed using OcraFlex 9.4, specialized program for analyzing marine structures. The numerical study shows that the damage index method can identify damage in the riser.

The paper presents an experimental result to characterize the behaviour of steel beams reinforcement by pultruded reinforced polymer strips. Steel beam members reinforced with different thick AFRP on bottom flange plate were tested under one point bending configuration. Test results showed that the member force of one ply reinforced specimen was increased as 11% than control specimen when the two ply overlapped specimen was increased as 14% as usual.

It is same such as the provision of shear buckling strength of steel composite box girder web panel and plate girder web panel in Korea Highway Bridge Design Standards(2012). But the web panel of steel composite box girder is different from the web of plate girder in that the upper slab and lower flange are connected to the web. So a different shear behavior of the girders is expected. In this study, To calculate a reasonable elastic shear buckling strength of steel composite box girder web panel, ABAQUS program was used. The results from F.E.A and previous studies are compared.

The bond strength is not enough due to the delaminate of epoxy between FRP and steel. However, the adhesion reinforcement method can improve the bond strength between steel plate and FRP plate. In this study, a bolt tighting and FRP sheet wrapping methods were used to improve bond strength between steel plate and FRP plate. Also, flexural test were performed according to the attachment pattern for AFRP plate strengthened steel beams.

Recently, the use of buried flexible pipes is widespread and ever increasing trend in the construction field. In this paper, we present the result of an investigation pertaining to the pipe stiffness of buried unplasticized polyvinyl chloride (PVC-U) pipes. To estimate the mechanical properties of PVC pipe produced by the domestic manufacturers, tensile test specimens were prepared and tested. In addition, parallel plate loading tests for the pipes with 150mm and 400mm inside diameters were conducted. From the test result, the pipe stiffness according to the ASTM D 2412 (2008) is estimated.

An experimental study was carried out to evaluate the punching shear performance of H-steel column + RC slab system for vertical load. Three specimens were constructed for interior column-slab system. All specimens were the same configuration and material properties except for columns such as RC column+flat plate slab and H-Steel column+flat plate slab. From the test results structural characteristics (maximum proof stress, maximum displacement, deformation capabilities and so on) are obtained and evaluated.

This study numerically investigates flexural behavior of press braked U-type section girders for fabrication simplicity. In order to improve structural stability during construction, the top flanges of press braked U section girder are laterally braced by installation of precast half-deck. Thus, laterally unbraced length is taken by the pocket spacing of the half-deck. This study performed 3D nonlinear finite element analyses on the U-type section girders along with inner bend radii to thickness ratio (ri/t). The numerical models reflect initial imperfection and residual stress. Through the finite element analyses, the flexural strength of the press-braked U-type section models were compared with those of general welded girder.

To inject CO2 in geological formations, deep wells that penetrate the formations need to be constructed. The seal integrity of deep wells for CO2 leakage are enhanced by annulus cements. By injecting CO2, brine in formations can be carbonated and the potential degradation of annulus cement in the carbonated brine has been brought up. In this paper, Type G oil well cement (OWC) pastes are hydrated for 28 days. Conditions of geosequestration in a sandstone formation at a depth of roughly 1 km, was simulated by bubbling CO2 into a heated vessel containing brine. The hydrated OWC cylindrical specimens were exposed to this environment. Slices of the cement specimen were taken periodically, during and after exposure to quantify degradation progression. The elastic modulus of the specimens was examined prior to and after exposure. After 28 days of exposure, the degraded depth of specimen was measured as 4.137 mm. The elastic modulus of the specimens was measured as 2.2 GPa and 3.2 GPa prior to and after exposure respectively. Considering a composite action in the partially degraded specimen, the elastic modulus of degraded part can be extracted. The results indicated that the difference of elastic modulus in the partially degraded annulus cements could occur a composite action of deep wells subject to axial load and shear cracks would be generated due to the composite action.