• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.6
• /
• pp.1687-1694
• /
• 2014

Recently FRP of carbon fibers is utilized as a repairing and reinforcing material for concrete structures. In this study, the bond performance between CFRP planks and ductile fiber reinforced cementitious composites was evaluated in order to develop a new system of concrete bridge deck to take advantage of the FRP planks of carbon fiber using as a permanent formwork. In order to strengthen the bonding between the FRP and cast-in-place concrete, an epoxy resin circulated in the market generally was fitted with a silica sand. The bond stress of ordinary concrete appeared in 2.11~5.43MPa and the bond stress of ductile fiber reinforced cementitious composites DC1 (RF4000) and DC2 (PP) respectively were 3.91~5.60MPa, 2.92~5.21MPa and the average bond stress of DC3 (RF4000+RSC15) and DC4 (PP+RSC15) were 4.80~5.58MPa, 5.57~5.89MPa.

• Journal of the Korea Institute of Building Construction
• /
• v.1 no.1
• /
• pp.143-150
• /
• 2001

Permanent-Form is one of system forms for reducing human labor, work costs, oscillation, noise, construction wastes and so on. Permanent-Form is made from precast method in facilities, and carried in construction site to assemble with no demolding. The biggest expense to produce permanent-Form is about manufacturing mold. This papers about structural efficiency evaluation, construction efficiency test. The result of this study is below. (1) In the compressive strength test of column. Fly ash specimen and polymer specimen's strength developed as each 8%, 14% to comparison with standard specimen. The reason of this result from form section area increase and form's reinforcing bar (2) The Degree of column crack in permanent form is lower than another one's The glass fiber's fiber reinforcement effect brings like this. (3) In the flexural load test of beam, the early crack load and maximum load of permanent form use specimen showed 20% higher than standard specimen's. (4) In field application experiment, an constructional error is satisfied with the allowable margin of error, $\pm$5mm (5) When the concrete is placed into the form inside, The transformation degree of permanent form is lower than plywood form's. (6) The concrete packing ability of permanent form is satisfactory. (7) The bonding strength of permanent form shows enough strength - 6kgf/$\textrm{cm}^2$.

• 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.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.6
• /
• pp.4245-4252
• /
• 2015

In this study, an experiment which utilized glass fiber reinforced polymer(GFRP) plank as the permanent formwork of cast-in-place high strength concrete structures was performed. The GFRP plank currently being produced has smooth surface so that it causes problems in behavior with concrete. Therefore, this research analyzed the flexure/shear failure behavior of composite beams, which used GFRP plank as its permanent formwork and has short shear span ratio, by setting the sand coated at GFRP bottom surface, the perforation and interval of the GFRP plank web, and the width of the top flange as the experimental variables. As a result of the experiments for effectiveness of sand attachment in case of not perforated web, approximately 47% higher ultimate load value was obtained when the sand was coated than not coated case and bending/shear failure mode was observed. For effectiveness of perforation and interval of gap, approximately 24% higher maximum load value was seen when interval of the perforation gap was short and the fine aggregate was not coated, and approximately 25% lower value was observed when the perforation gap was not dense on the coated specimen. For effectiveness of top flange breadth, the ultimate load value was approximately 17% higher in case of 40mm than 20mm width.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2002.10a
• /
• pp.495-500
• /
• 2002

The purpose of this study is to develop and to apply this permanent cement mortar form as one of those system forms to improve existing form's problems. (1) In the fire proof test with combined specimen, the fire proof covering including form section thickness is satisfied with the fire proof criterion. It is considered that form section thickness has no problem (2) The suitable method of normal pressure steam curing for the form's mass production is 4 hours in 65℃ considering production cost, the silica fume admixture is economic.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1998.10b
• /
• pp.900-905
• /
• 1998

This study is about quality test of parmament form for practical application. Nowdays domestic building market in the face of 3D, in addition to construction cost increase, materials lack problems and opening a building market to foreign countries, is trying to find out the efficient ways of overcoming these problems. So the efficiacy of form work to technical improvement will contribute a practical permanent form in field through quality test of permmament form. In this paper, we examined the total system of form erections and evaluated the structural permament of columns and beams.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.3
• /
• pp.21-31
• /
• 2018

This paper presents an experimental investigation on the structural performance of precast ribbed panel specimens and bridge deck specimens fabricated from the panels. The panel specimens are developed for permanent deck forms of railway bridges (PSC girder). The decks of railway bridges have short lengths compared with highway bridges. Therefore, precast panels for railway bridges are different from those of highway bridges. The precast panels have ribs designed for crack control at the bottom of the sections. Two kinds of specimens were examined: one with 400-mm width and one with 1200-mm width. Three specimens of each type were fabricated, and a total of 12 specimens were tested. In this test, the ultimate load, strain of the reinforcement and concrete, crack width, deformation, and slip were measured. The structural performance of the specimens was assessed using the Korea railway bridge design code and Eurocode. All specimens met the current design criteria for structural strength and serviceability.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.25 no.6
• /
• pp.60-67
• /
• 2021

In lately, it's been developed and used a system of using deck plates as formwork in order to solve various problems caused by conventional formwork system. This system is more economical and has higher constructability than the conventional system by permanently embedding most of deck plates into the members. However, for this kind of embedded deck plates formwork system, it's been reported that it is difficult to verify filling of concrete in members like beams with narrow width and complicated rebar arrangement. In addtion, there are several problems such as corrosion of deck plates in terms of constructability and maintenance. Therefore, in this study, it is attempted to develop a removal-deck plate formwork system for beams by removing deck plates after concrete curing. The system consists of a deck plate module that acts as form, a frame preventing deformation by concrete lateral pressure, stirrup frame, and connector that combines these. As a result of this research, it is verified that it has higher constructability, efficiently prevents deformation caused by concrete lateral pressure and could be easily removed in the developed formwork system.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.13 no.2 s.54
• /
• pp.122-128
• /
• 2009

This study is to improve constructability of LB-DECK construction in site such as inconvenience of main and distribution bars in arrangements LB-DECK Panel which is work is applied to many bridges these days as a permanent formwork. So, the constructability is improved by changing the method of allocation of main reinforcing bar and distribution bar which is reviewed for improving efficiency of design and construction process among the suggested methods. The crack shapes, deflections, and strains under static load of the improvement of LB-DECK Panel are compared and analyzed to former LB-DECK Panel. As a result, 13% of strength compared to before the improvement of LB-DECK Panel, and 10% of strength is increased in the case of slab.

• Magazine of the Korea Concrete Institute
• /
• v.14 no.5
• /
• pp.31-38
• /
• 2002

최근 환경문제에 대한 일반인의 관심고조와 함께 3D 기피현상에 따른 철근공, 거푸집공 등의 기능노동자의 부족, 고령화, 외국인노동자 고용 현상과 낮은 노동생산성은 건설업계의 심각한 현안이다. 과거에는 재료비의 비중이 높았으므로 재료의 낭비를 줄이기 위한 합리화가 추진되었다. 그러나 현재는 노무비 비율의 급격한 증대로 인하여 공기단축이나 합리화, 시스템화를 통해서 경쟁에서 생존해 나가고 있다. 건축공사 중 특히 철근 콘크리트공사는 기술의 발전이 느리고, 시공 방법도 과거의 공법을 그대로 유지하고 있는 실정이다. 건축공사비 중 구체공사의 비율은 30% 정도이고, 그 비용 중 인건비가 50% 정도를 차지하고 있기 때문에 철근 콘크리트 공사는 아직도 기술 집약적인 산업이 아닌 노동 집약적 산업으로 간주되는 결과를 초래하고 있다.(중략)