• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2866-2871
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• 2011

In this study, computation method of tensile load which develops in tie-bar of reinforced earth, connection strength between tie-bar and eco-block and shear strength of the interface between two eco-blocks were verified by experiments. According to the test results of connection strength test, peak tensile load of D13 deformed bar were close to allowable tensile load of it for situation of infill with soil. Connection strengths of D10 and D13 deformed bars were greater than the allowable tensile load of those respectively for situation of infill with concrete. According to the test results of shear strength of the interface between two eco-blocks, shear resistance parameters, ${\alpha}_u$ and ��${\lambda}_u$ were evaluated as 1.7kN/m and 2$27.6^{\circ}$ respectively.

• Computational Structural Engineering
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• v.5 no.4
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• pp.133-142
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• 1992

An analytical model was developed for predicting the pullout behavior of straight beam longitudinal bars anchored at exterior beam-column connections. The model incorporates a local bond constitutive simulation capable of considering the effects of anchored bar diameter, yield strength and the spacing, concrete compressive strength, and column pressure on the bond characteristics of deformed bars in confined conditions of exterior joints. The analytical techniques adopted in this study were shown to satisfactorily predict the results of pullout tests on straight bars embedded in confined concrete specimens. An evaluation of the ACI-ASCE Committee 352 development length requirements in exterior joint conditions was made using the developed analytical approach. The results of this analytical evaluation are indicative of the conservatism of the current development length requirements in the confined conditions of exterior joints.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.863-866
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• 2008

One of the most important requirements for reinforced concrete constructions is the bond behavior between concrete and reinforcement. In this study, the positions (i.e., vertical, horizontal) and the locations (i.e., 225mm and 75mm) of reinforcement were considered as a main test parameter. The ready mixed recycled aggregate concrete concrete with specified strength of 21MPa was prepared with different replacement ratio(i.e 0%, 100%) of recycled coarse aggregate. From the test results, it was bond that under the same mix proportion (i.e., the mix proportions are the same, except for deformed bars position), the bond strength between the recycled coarse aggregate concrete and the reinforcement has obvious relation with reinforcement position. Also, the specimens of top position showed a lower bond stress than that provided in CEB-FIP Code.

• Journal of Korean Society of Steel Construction
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• v.23 no.6
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• pp.725-736
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• 2011

In a composite beam, a shear connector is installed to resist the horizontal shear on an interface between steel beams and reinforced concrete slabs. The steel-wire-integrated deck plate slab is commonly used at the wide section beam. Then vertical bars are installed at the upper wire of the ends of the steel truss girder to ensure safety during the construction. The new type of shear connector is made of deformed bar and steel plates, and must function as vertical bars but must have higher shear capacity. This paper examines the ways to develop and utilize this new shear connector. From the push-out experiments, a shear connector made of a continuous deformed bar and steel plate showed a higher shear capacity and ductility than a ${\phi}16$ stud connector, and functioned as a vertical bar.

• 레미콘
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• no.3 s.31
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• pp.32-41
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• 1992

• Magazine of the Korea Concrete Institute
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• v.6 no.2
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• pp.169-179
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• 1994

Recently the construction of residential buildings faces many difficulties due to the shortage of building materials and works. Simplifying the stage of processing and assembling reinforcing rods and increasing the efficiency of them in reinforced concrete construction can be used to settle the difficulties. In the respect, structural wire-fabric and loop wire-fabric is utilized. The purpose of this study, on condition of being $210kg/cm^2$ concrete strength, is to analyze the structural and flexural properties of one-way concrete slabs by testing with different reinforcing type, tensile steel ratio based with minimum steel ratio, boundary condition and splice length which affect the maximum width of crack and ductility factor. From the test results, the ductility factor is approved that the slabs using deformed bar were much better than that using wire-fabric, and 30D of splice length was appropriate in the slabs as splice length. In the control of the maximum crack width the slabs using wire-fabric and loop wire-fabric were much better than that using deformed bar.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.3
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• pp.404-408
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• 2006

In this paper, connection strength between facing block and tie-bar was investigated through experimental study with varying in-fill material such as concrete, soil and crushed stone. Also, connection strength between anchor block and tie-bar was investigated with varying in-fill material. According to the experimental results, in case of using in-fill concrete, connection strength between facing block and tie-bar was larger than allowable tension load of tie-bar. Whereas in case of using in-fill soil or crushed stone, connection strength between facing block and tie-bar was less or similiar to allowable tension load of tie-bar. Connection strength between anchor block and tie-bar for which crushed stone was used as in-fill material, was larger than allowable tension load of tie-bar.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.430-439
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• 2002

The development of reinforcing steel is required in reinforced concrete structures. The standard hooks that have been widely used for the tensile development in the beam-column joints tend to create difficulties of construction such as steel congestion as the member cross sections are becoming smaller due to the use of higher strength concrete and higher grade steel. Using the reinforcing bars with end mechanical anchoring device (headed reinforcement) provides potential economies in construction such as reduction in development lengths, simplified details, and improved responses to cyclic loadings. In this paper, the pullout strengths and behaviors of the headed reinforcement were experimentally studied. In 33 pullout tests performed using D25 deformed reinforcing bars, the test parameters were embedment depth, edge distance, head size, and the use of transverse reinforcement. The pullout strengths determined from tests closely agreed with the pullout strengths predicted using the CCD method. The pullout strengths increased with increasing embedment depths nd edge distances. The strengths tend to increase with the use of larger heads. From the experimental program where the effect of the transverse reinforcement was examined, a modification factor to the CCD was suggested to represent the effect of such reinforcement that is installed across the concrete failure plane on the pullout strengths.

• Journal of the Korea Institute of Building Construction
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• v.23 no.5
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• pp.509-517
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• 2023

The surge in FRP(Fiber Reinforced Plastic) research signifies the industry's pursuit to counteract the longstanding issue of rebar corrosion. Notably, Carbon Fiber Reinforced Plastic(CFRP) emerges as a commendable alternative, given its superior resistance to both corrosion and chemical interactions, thus positing itself as a potential replacement for traditional steel rebars. However, the layered composition of fibers and resin in CFRP flags a notable susceptibility to elevated temperatures. Despite its promise, comprehensive studies elucidating the full spectrum of CFRP properties remain ongoing. In this investigative study, we meticulously assessed the bond strength of CFRP post-exposure to high thermal conditions. Our findings underscored a parity in bond strength amongst silica sand-coated CFRP, rib-type CFRP, and Glass Fiber Reinforced Plastic(GFRP).

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.6
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• pp.557-569
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• 2011

Steel Fiber Reinforced Concrete (SFRC) is widely used for tunnel structures such as shotcrete and segments. Corrosion of steel fibers and steel reinforcements may affect on the long-term durability of the concrete structures with steel fibers and reinforcement. Therefore, a study on the feasible method to evaluate corrosion possibility and permeability of the concrete structures is required. This experimental study examines the effect of steel fibers and internal reinforcement on the surface resistivity. Steel fiber mix ratio and corrosion of internal reinforcement were considered as variables. In the results, steel fibers significantly reduce the surface resistivity due to those conductive characteristic. In the case of 3% mix ratio, it was difficult to evaluate rate and permeability of corrosion due to the great reduction of resistivity by mixing of steel fibers.