• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1993년도 봄 학술발표회 논문집
• /
• pp.136-141
• /
• 1993

8 Wall specimens (1/2 scaled) used welded wire fabric (Ф=6mm) and ordinary deformed reinforcement(D6) of which their ultimate tensile strength were almost same were tested to investigate the inplane-flexural behavior. Test results show that : 1. The wall strength with welded wire fabric was 20% less than that with deformed bar. 2. The wall ductility ratio of welded wire fabric was 1/3 times than that of deformed bar, approximately. 3. It is recommened that lap splice of welded sire fabric should be avoided in critical fracture zone.

• 콘크리트학회지
• /
• 제6권4호
• /
• pp.153-160
• /
• 1994

본 연구는 용접철망을 사용한 반두께 프리캐스트 콘크리트 슬래브의 휨내력 평가 및 연성능력 검토를 위하여 총 10개의 일방향 반두께 프리캐스트 콘크리트 슬래브를 제작하여 2점 단순 재하를 하였다. 주요변수로서는 상부콘크리트 압축강도, 반두께 슬래브의 표면거칠기, 그리고 인장철근비로 구성되었으며, 실험결과는 다음과 같다. 반두께 프리캐스트 콘크리트 슬래브의 휨설계는 국내 극한강도 설계법에 의한 슬래브 설계방식의 사용이 가능한 것으로 나타났다. 슬래브에 $4000kg/cm^2$이상의 용접철망을 사용할 경우 기존의 규준에 따라 항복응력도를 변형율 0.0035에 해당하는 응력도를 사용하는 것이 안정적인 것으로 나타났다. 용접철망을 사용한 슬래브의 경우 철근 콘크리트 연성평가에 따라 분석한 결과 연성부담능력이 저하되어 용접철망을 경우에는 연성증진을 위한 일반철근을 혼용하는 것이 바람직한 것으로 판단된다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1993년도 봄 학술발표회 논문집
• /
• pp.130-135
• /
• 1993

Twelve 1/2 scale modeled wall specimens were tested statically up to failure to investigate she shear behavior of concrete walls reinforced with welded wire fabric. major variables were spacing of reinforcing bars, type of reinforcing bar(rebar, welded sire fabric, knurling wire) and the existence of tied column type reinforcement

• Structural Engineering and Mechanics
• /
• 제49권4호
• /
• pp.449-461
• /
• 2014

The use of low-ductility welded wire fabric (WWF) as a main tensile reinforcement in concrete slabs compromises the ductility of concrete structures. Lower ductility in concrete structures can lead to brittle and catastrophic failure of the structures. This paper presents the experimental study carried out on eight simply supported one-way slabs to study the structural behavior of concrete slabs reinforced with low-ductility WWF and steel fibers. The different types of steel fibers used were crimped fiber, hooked-end fiber and twincone fiber. The experimental results show that the ductility behavior of the slab specimens with low-ductility reinforcement was significantly improved with the inclusion of $40kg/m^3$ of twincone fiber. Distribution of cracks was prominent in the slabs with twincone fiber, which also indicates the better distribution of internal forces in these slabs. However, the slab reinforced only with low-ductility reinforcement failed catastrophically with a single minor crack and without appreciable deflection.

• 콘크리트학회지
• /
• 제6권2호
• /
• pp.169-179
• /
• 1994

주택건설은 극심한 건축자재 부족과 인력수급등의 많은 어려움을 격고 있는데, 이에 대한 문제의 해결방은 중 하나로 철근콘크리트 공사에서 철근의 가공조립공정을 보다 간소화하면서 그 기능의 효율성을 높이는 방법으로 구조용 용접철망과 루프형 용접철망을 이용한 공법이 제기되고 있다. 본 연구에서는 일방향 슬래브에 콘크리트 예상 압축강도가 $210kg/cm^2$일 때, 최대균열폭과 소성변형 능력에 영향을 미치는 요인인 사용철근의 종류, 최소철근비를 기준으로 한 인장철근비(${\rho}t$), 주변지지조건, 겹이음길이의 4가지 주요변수로 하여 슬래브의 구조적 특성 및 휨거동을 파악하는데 그 목적을 두었다. 연구결과, 소성변형능력은 이형철근을 사용한 슬래브가 용접철망을 사용한 슬래브보다 월등히 큰 것으로 나타났고, 겹이음된 슬래브에서는 겹이음길이 30D가 적절한 것으로 나타났다. 또한 최대균열폭은 용접철망과 루프형 용접철망을 사용한 슬래브가 이형철근을 사용한 슬래브 보다 균열폭을 억제하는 것으로 나타났다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
• /
• pp.95-98
• /
• 2005

The objective of this experimental study was to understand the structural behavior of reinforced concrete continuous deep beams with welded deformed wire fabric(WWF) as shear reinforcement. The structural behavior of deep beams reinforced with WWF was compared with that of deep beams reinforced with orthogonal shear reinforcement which had standard anchorage corresponding to ACI 318-02. Test results showed that the load transferring capacity and the control of splitting cracks in the strut of WWF were almost as effective as those of orthogonal shear reinforcement with standard anchorage.

• Structural Engineering and Mechanics
• /
• 제70권2호
• /
• pp.133-141
• /
• 2019

The aim of the present paper is to present the cyclic behavior of strengthened reinforced concrete shear wall test specimen, which was reinforced with cold drawn welded wire mesh fabric. Two reinforced concrete shear wall specimens have been tested in the present study. The walls were tested under reversed cyclic loading with loading applied near the tip of the walls. The control wall is tested in its original state to serve as a baseline for the evaluation of the repair and strengthening techniques. The two test specimens include a control wall and a repaired wall. The control wall test specimen was designed and detailed to simulate non-ductile reinforced concrete shear walls that do not meet the modern seismic provisions. The response of the original wall was associated with the brittle failure. The control shear wall was repaired by addition of the reinforcements and the concrete and then it was reloaded. The effectiveness of the repair technique was investigated. Test results indicate that there can be a near full restoration of the walls' strength. The data from this test, augmenting other data available in the literature, will be useful in calibrating improved analytical methods as they are developed.

• Structural Engineering and Mechanics
• /
• 제65권3호
• /
• pp.223-231
• /
• 2018

A numerical investigation of the impact of steel ductility on the strength and ductility of two-way corner and edge-supported concrete slabs containing low ductility welded wire fabric is presented. A finite element model was developed for the investigation and the results of a series of concurrent laboratory experiments were used to validate the numerical solution. A parametric investigation was conducted using the numerical model to investigate the various factors that influence the structural behavior at the strength limit state. Different values of steel uniform elongation and ultimate to yield strength ratios were considered. The results are presented and evaluated, with emphasis on the strength, ductility, and failure mode of the slabs. It was found that the ductility of the flexural reinforcement has a significant impact on the ultimate load behavior of two-way corner-supported slabs, particularly when the reinforcement was in the form of cold drawn welded wire fabric. However, the impact of the low ductility WWF has showed to be less prominent in structural slabs with higher levels of structural indeterminacy. The load-deflection curves of corner-supported slabs containing low ductility WWF are brittle, and the slabs have little ability to undergo plastic deformation at peak load.

• Computers and Concrete
• /
• 제22권1호
• /
• pp.27-37
• /
• 2018

Reinforced concrete structures are widely used in civil engineering projects around the world in different designs. Due to the great evolution in computational equipment and numerical methods, structural analysis has become more and more reliable, and in turn more closely approximates reality. Thus among the many numerical methods used to carry out these types of analyses, the finite element method has been highlighted as an optimized tool option, combined with the non-linear and linear analysis techniques of structures. In this paper, the behavior of reinforced concrete beams was analyzed in two different configurations: i) with welding and ii) conventionally lashed stirrups using annealed wire. The structures were subjected to normal and tangential forces up to the limit of their bending resistance capacities to observe the cracking process and growth of the concrete structure. This study was undertaken to evaluate the effectiveness of welded wire fabric as shear reinforcement in concrete prismatic beams under static loading conditions. Experimental analysis was carried out in order compare the maximum load of both configurations, the experimental load-time profile applied in the first configuration was used to reproduce the same loading conditions in the numerical simulations. Thus, comparisons between the numerical and experimental results of the welded frame beam show that the proposed model can estimate the concrete strength and failure behavior accurately.

• 콘크리트학회지
• /
• 제6권4호
• /
• pp.161-168
• /
• 1994

반두께 P.C. 슬래브는 슬래브의 일부분(하부)을 프리캐스트로 제작하고 상부에 현장 콘크리트를 타설하는 공법으로서 반두께 슬래브가 휨변형을 일으킬 때 접합면사이에서는 수평전단력이 발생하게 된다. 본 연구에서는 이러한 수평전단력에 저항하기 위한 방법으로 스크랫치 방법을 도입하였다. 주요 변수로서는 상부콘크리트의 압축강도, 전단철근의 유무, 콘크리트 표면거칠기, 그리고 용접철망과 전단철근의 결합유무등으로 되어있다. 모든 실험체의 접합면의 면적(A$_c$)은 3,2000$cm^2$으로 동일하다. 실험결과, 콘크리트 표면처리 깊이가 증가할수록 전단강도는 증가하였으며 전단철근이 없이 표면거칠기만에 의해 수평전단강도를 확보할 수 있었다. 콘크리트의 압축강도가 증가함에 따라 수평전단강도는 증가하였다. 또한 전단강도를 예측하기 위한 전단계수 결정식을 도출하였다.