• Computers and Concrete
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• v.8 no.6
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• pp.631-645
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• 2011

The capacity design rule for beam-column joints, as adopted by the EC8, forces the formation of the plastic hinges to be developed in beams rather than in columns. This is achieved by deriving the design moments of the columns of a joint from equilibrium conditions, assuming that plastic hinges with their possible overstrengths have been developed in the adjacent beams of the joint. In this equilibrium the parameters (dimensions, material properties, axial forces etc) are, in general, random variables. Hence, the capacity design is associated with a probability of non-compliance (probability of failure). In the present study the probability of non-compliance of the capacity design rule of joints is being calculated by assuming the basic variables as random variables. Parameters affecting this probability are examined and a modification of the capacity design rule for beam-column joints is proposed, in order to achieve uniformity of the safety level.

• Journal of Korean Association for Spatial Structures
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• v.22 no.1
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• pp.59-66
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• 2022

In this paper, the flexural capacity equation of FRP-bar reinforced concrete beams was verified by comparing the experimental results and flexural capacity obtained according to the ACI procedure. And, also the economic feasibility of FRP-bar reinforced concrete beams was analyzed by comparing nominal moment capacity of beams. The results of analysis were as follows, 1) GFRP concrete beams have lower flexural performance than reinforced concrete beams, whereas CFRP concrete beams have similar flexural performance to reinforced concrete beams under the same reinforcement ratio 2) Although the design moment increased as the compressive strength of concrete increased, the flexural performance of GFRP reinforced concrete beams was found to be lower than the reinforced concrete beams for all reinforcement ratios.

• International Journal of Concrete Structures and Materials
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• v.5 no.1
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• pp.35-42
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• 2011

In this paper, a design equation for the punching shear capacity of steel fiber reinforced concrete (SFRC) slabs is proposed based on the Japan Society of Civil Engineers (JSCE) standard specifications. Addition of steel fibers into concrete improves mechanical behavior, ductility, and fatigue strength of concrete. Previous studies have demonstrated the effectiveness of fiber reinforcement in improving the shear behavior of reinforced concrete slabs. In this study, twelve SFRC slabs using hooked-ends type steel fibers are tested with varying fiber dosage, slab thickness, steel reinforcement ratio, and compressive strength. Furthermore, test data conducted by earlier researchers are involved to verify the proposed design equation. The proposed design equation addresses the fiber pull-out strength and the critical shear perimeter changed by the fiber factor. Consequently, it is confirmed that the proposed design equation can predict the punching shear capacity of SFRC slabs with an applicable accuracy.

• Computers and Concrete
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• v.10 no.5
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• pp.507-521
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• 2012

The capacity design of shear forces is one of the special demands of EC8 by which the ductile behavior of structures is implemented. The aim of capacity design is the formation of plastic hinges without shear failure of the elements. This is achieved by deriving the design shear forces from equilibrium conditions, assuming that plastic hinges, with their possible over-strengths, have been formed in the adjacent joints of the elements. In this equilibrium situation, the parameters (dimensions, material properties, axial forces etc) are random variables. Therefore, the capacity design of shear forces is associated with a probability of non-compliance (probability of failure). In the present study the probability of non-compliance of the shear capacity design in columns is calculated by assuming the basic variables as random variables. Parameters affecting this probability are examined and a modification of the capacity design is proposed, in order to achieve uniformity of the safety level.

• Steel and Composite Structures
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• v.24 no.6
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• pp.679-688
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• 2017

A GFRP-concrete composite bridge deck is presented in this paper. This composite deck is composed of concrete and a GFRP plate and is connected by GFRP perfobond (PBL) shear connectors with penetrating GFRP rebar. There are many outstanding advantages in mechanical behavior, corrosion resistance and durability of this composite deck over conventional reinforced concrete decks. To analyze the shear and flexural performance of this GFRP-concrete composite deck, a static loading experiment was carried out on seven specimens. The failure modes, strain development and ultimate bearing capacity were thoroughly examined. Based on elastic theory and strain-based theory, calculation methods for shear and flexural capacity were put forward and revised. The comparison of tested and theoretical capacity results showed that the proposed methods could effectively predict both the flexural and shear capacity of this composite deck. The ACI 440 methods were relatively conservative in predicting flexural capacity and excessively conservative in predicting shear capacity of this composite deck. The analysis of mechanical behavior and the design method can be used for the design of this composite deck and provides a significant foundation for further research.

• Smart Structures and Systems
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• v.2 no.1
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• pp.81-100
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• 2006

To calculate the shear capacity of concrete beams reinforced with fibre-reinforced polymer (FRP), current shear design provisions use slightly modified versions of existing semi-empirical shear design equations that were primarily derived from experimental data generated on concrete beams having steel reinforcement. However, FRP materials have different mechanical properties and mode of failure than steel, and extending existing shear design equations for steel reinforced beams to cover concrete beams reinforced with FRP is questionable. This paper investigates the feasibility of using artificial neural networks (ANNs) to estimate the nominal shear capacity, Vn of concrete beams reinforced with FRP bars. Experimental data on 150 FRP-reinforced beams were retrieved from published literature. The resulting database was used to evaluate the validity of several existing shear design methods for FRP reinforced beams, namely the ACI 440-03, CSA S806-02, JSCE-97, and ISIS Canada-01. The database was also used to develop an ANN model to predict the shear capacity of FRP reinforced concrete beams. Results show that current guidelines are either inadequate or very conservative in estimating the shear strength of FRP reinforced concrete beams. Based on ANN predictions, modified equations are proposed for the shear design of FRP reinforced concrete beams and proved to be more accurate than existing equations.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.565-570
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• 1997

This study is on the strength capacity and the strengthening effects of crarbon fiber sheets(CFS) and glass fiber sheets (GFS) on steel reinforced concrete(SRC) beams. SRC beams are often used on high-rise building construction to save story height and construction cost. However, there are no strengthening design code in Korea and most engineers design it as steel beams ignored the composite effect if reinforced concrete. Test results on steel reinforced concrete beams reveal thar the strength capacity of SRC beam is more than simple addition of steel and reinforced concrete beams. In case of steel reinforced concrete beams, ultimate moment capacity of strengthening beam of carbon fiber sheets is 120% of non-strengthening one.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.4
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• pp.171-181
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• 2003

This study concerns the prediction of shear capacity, as governed by concrete breakout failure, concrete pryout failure and steel failure, of single anchors located close to free edge and located far from a free edge and installed in uncracked, unreinforced concrete. For this purpose, the methods to evaluate the shear capacity of the single anchors in concrete are summarized and the experimental data are compared with capacities by the two present methods: the method of ACI 349-90 and concrete capacity design (CCD) method.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.151-156
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• 2003

On the basis of the philosophy that "the compressive axial load capacity after spalling of shell concrete should be maintained as that before spalling" by applying the confinement model of high strength concrete proposed in the previous proceeding paper and equivalent lateral confining pressure considering configurations of transverse reinforcement, the amounts of transverse reinforcement from the compressive capacity design method about high strength reinforced concrete tied columns can be calculated through the formula proposed in this paper. The proposed design equation of transverse steel amounts for high strength reinforced concrete tied columns was quite agreeable with the test results of HSC tied columns conducted by other researchers as well as author.as author.

• Journal of Korean Society of Steel Construction
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• v.26 no.1
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• pp.11-20
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• 2014

The Concrete Capacity Design(CCD) method has been used in the design of anchor since 2001 and Korean design code specify that concrete breakout capacity of CIP anchor under seismic load shall be taken as 75% of static capacity. In this study, an experimental study was performed to evaluate the concrete breakout capacity of unreinforced CIP anchors under dynamic shear force. For the purpose, three static and dynamic shear-loading tests were conducted using 20mm diameter anchors, respectively. The edge distance of 120mm was considered in the tests. In the dynamic tests, 15 cycles pulsating load with 1Hz speed was applied and the magnitude of loading step was increased until concrete breakout failure occurs. From the tests, the concrete breakout capacity under dynamic shear loading showed nearly same capacity by static loading.