전단보강근이 없는 섬유보강 철근콘크리트 보의 특성에 관한 실험적 연구

김정섭,고송균,최진석,Kim, Jeong-Sup,Go, Song-Kyoon,Choi, Jin-Seok 한국건축시공학회 2003 한국건축시공학회지 Vol.3 No.3

This study examines the material characteristics of fibers and their influences on reinforced concrete through the tests of reinforced concrete by the types of fibers including non-reinforced, steel, polypropylene and cellulose fibers and the test of compressive strength and reinforced concrete beam without shear reinforcement and consequently it obtains the following conclusions. As a result of conducting compressive strength by the types of specimens, fiber reinforced specimen with the highest compressive strength value at 28 days of age was cellulose fiber reinforced specimen as 280.4kgf/$\textrm{cm}^2$ and steel fiber specimen had the highest compressive strength of 250.7kgf/$\textrm{cm}^2$ at 180 days of age. In case of non-reinforced specimen, its compressive strength was 277.4kgf/$\textrm{cm}^2$ at 28 days of age and 273.1kgf/$\textrm{cm}^2$ at 180 days of age. Comparing the compressive strength of non-reinforced specimen to that fiber reinforced specimen showed that the compressive strength of fiber reinforced specimen was lower in the passage of age and the results of this experiment showed no effects of fiber reinforcement. As a result of testing reinforced concrete beam without shear reinforcement, ductility factors of specimens were 4.67 for non-reinforced specimen, 8.18 for steel fiber reinforced specimen, 6.20 for polypropylene fiber reinforced specimen and 5.49 for cellulose reinforced specimen, and it is found that steel fiber reinforced specimen was highest. When non-reinforced specimen and steel fiber reinforced specimen were compared, steel fiber reinforced specimen had higher ductility factor of about 75.2% than that of non-reinforced specimen.

炭素纖維板으로 補强한 鐵筋콘크리트보의 構造的擧動에 관한 實驗的 硏究

김하진,고송균,박영배,조창호,김정섭 朝鮮大學校 建設技術硏究所 1998 建設技術硏究 Vol.18 No.1

This study is a part of research to improve the yield strength of concrete structure with a structural damage and conducts the experiment with the variables such as the period of restrengthening of specimen, restrengthening length (1.9m, 1.5m, 1.0m) and restrengthening effect according to restrengthening mehthod of restrengthening materials (nonrestrengthening, Anchor, Angle) to test bending behavior and yield strength performance of reinforced concrete beams restrengthened with carbon fiber laminate. As a result of experiment, in the restrengthening effects by the period of restrengthening, specimen restrengthened before loading, during reloading and after loading show 1.9m, 1.5m and 1.0m respectively, in the restrengthening effects according to restrengthening length, specimen restrengthened with 1.9m, 1.5m and 1.0m show 113.7%, 122.4% and 112.7% and in restrengthening effects according to restrengthening method of restrengthening materials, non-restrengthening and restrengthening in anchor and angle show 113.7%, 115.9% and 184.4% of increase in yield strength respectively. Accordingly, the specimen restrengthened during loading, the specimen with 1.5m of restrengthening and the specimen restrengthened with angle show high restrengthening effects respectively. With the above results, a crack is closed by elastic behavior in the case of test materials, but since in the actual concrete strucutre, a crack is not closed like the specimen during loading, the influence of it on restrengthening should be considered. It is found that although restrengthening effect by the restrengthening length secures a sufficient length, the increase of yield strength by restrengthening cannot be expected when bonded performance is not secured and in deciding restrengthening method of restrengthening materials, the method which have not damage to restrengthening materials and can be integrated with restrengthening materials and structure is effective.

패각류가 함유된 해사를 사용한 철근콘크리트 보의 강도특성에 관한 실험적 연구 ( An Experimental Study on the Strength Characteristics of Reinforced Concrete Beams Using Sea-Sand Contained Shells )

최진석,조철희,고송균,손순채,김정섭 대한건축학회 2002 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.22 No.1

섬유시트로 보강된 철근콘크리트 기둥의 압축강도 특성에 관한 실험적 연구

김정섭,최진석,조철희,고송균,Kim, Jeong-Sup,Choi, Jin-Seok,Cho, Cheol-Hee,Go, Song-Kyoon 한국건축시공학회 2003 한국건축시공학회지 Vol.3 No.2

Test specimen test was performed using concrete reinforced with fiber sheet and the test variables were based on the kinds of fiber and the number of reinforcement layers. Using steel-concrete reinforced with fiber sheet, compression tests were performed and the test variables were the kinds of fiber, number reinforcement layers and reinforcement layer order. The following results were obtained: 1) It was demonstrated that compressive strength of the test specimen reinforced during test specimen test and member test increased as the number of reinforcement layers increased. 2) It was shown that non-reinforced test, specimen were destroyed during the member tests, but the specimen reinforced with CFS destroyed and the GFS-reinforced specimen and composite reinforced specimen showed ductile destruction. 3) As a result of tests on kinds of reinforcement fiber, it was demonstrated that CFS-reinforced test specimen had higher compressive strength in a 공시체 test. In the member test, 2ply-and 3ply-GFS reinforced specimens except lplied one had higher compressive strength. It was because partial destruction occurred due to the rate of height/section. 4) For layer strength order, compared with test specimen reinforced only with a single reinforced material, test specimen reinforced with CFS and GFS, and test specimen reinforced with CFS first showed better results in compressive strength and ductility judgement.

콘크리트 강도추정에 따른 초음파 속도와 반발경도의 상쇄효과에 대한 실험적 연구

김정섭,오승석,조창호,고송균,김성학 대한건축학회 1996 大韓建築學會論文集 Vol.12 No.11

鹽化物 含有梁에 따른 鐵分 腐蝕에 관한 實驗的 硏究

최진석,조철희,신용석,고송균,손순채,김정섭 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

As a result of separating river sand and sea sand into the corrosion increased according to the of thinnss or the coating and the Chloride Content and Corrosion of Steel Bar through the experiment, the following conclusions are obtained. 1. There was no corrosion in the case of treating the steel bar with anticorrosive among test specimens cured in the air for 60 days, corrosion was found in the test specimens not treated with anticorrosive and for 60 days of age. 2. The area of corrosion increased according to the thinnss of the coating and the chloride content wher exposed for are more than 60 days. Therefore, it was determined in general that the corrosion progressed more rapidly in water cured specimens than in air cured ones and this was due to the influence of C1_(￣) in the sea sand.

패각류가 함유된 철근콘크리트 보의 내력 및 거동에 관한 실험적 연구

김정섭(Kim Jeong-Sup),조창호(Cho Chang-Ho),고송균(Go Song-Kyoon),조철희(Cho Cheol-Hee),최진석(Choi Jin-Seok) 대한건축학회 2004 大韓建築學會論文集 : 構造系 Vol.20 No.1

This study makes experimental specimen to examine of concrete and structural characteristics of reinforced concrete beams such as shear destruction according to contents of shells in concrete using sea sand containing river sand and shells (8%, 10%, 20%, 30% and 40%) and age, evaluates its load, deflection, crack and destruction from load increase and ductility capacity and aims at supplying the data for applying it to actual structures. The results obtained through material test of concrete and static experiment of members using sea sand containing river sand and shells are as follows;<br/> As a result of strength test by shell contents, it is found that compressive strength of specimen using sea sand containing 8% of shells is highest and the more shell contents are, its compressive strength is reduced.<br/> Compressive strength of specimen using sea sand containing 8% of shells was reduced by 7.34% at 28 days of age and by 3.87% at 365 days of age compared to specimen using river sand.<br/> The flexural capacity test of reinforced concrete beam showed that specimen using sea sand containing shells has reduce ductility capacity compared to specimen using river sand.<br/> In strain of bar, specimen using river sand showed least result on tensile bar compressive bar and stirrup bar showed a great increase of strain of bar after yield. It is guessed that bar bear the compressive force and shear force after the loss of compressive strength of concrete.<br/> Therefore, in case of using sea sand containing shells, mixing and member design considering compressive strength and ductility capacity of concrete are needed. And it guessed that using sea sand containing over 10% of shells will be problematic.