• Journal of the Korean Wood Science and Technology
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• v.40 no.5
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• pp.327-334
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• 2012

Wood and concrete show significantly different physical properties, and it need to be firstly understood for using wood-concrete composite. This study is performed for compensating this and effective hybridization of wood and concrete. This research in planned for wood-concrete composite after previous research which deals the shear performance with different anchorage length of steel rebar in wood. Yield mode and reference design value (Z) were derived using EYM (European Yield Model). And the yield mode changed before and after anchorage length of 10~15 mm - $I_s$ mode to IV mode. There was not increasing tendency of shear performance with increased anchorage length for over 20 mm of anchorage in concrete. And wood composite shows 65% and 93% on initial stiffness and yield load respectively compared with the wood-concrete composite. Wood-concrete composite showed brittle failure after yield point while wood-to-wood composite showed ductile failure.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.579-584
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• 1998

The purpose of this study is to evaluate the flexural strengthening effects of RC beams reinforced with carbon fiber sheets (CFS) in variable of strengthening amount and anchorage length of CFS. This study can be summarized as follows. The CFS shares the tensile stress such as rebar during loading test. Also, as the strengthening amount of CFS is increased, the maximum flexural strength of RC beams reinforced with CFS is increased. Therefore, it is confirmed that the CFS's strengthening method is very effective to improve the flexural strength of RC beams. The maximum flexural strength of RC beams with CFS is determined by bond failure between CFS and concrete surface. So, the evaluation of CFS's strengthening effect can be calculated using the tensile stress of CFS which is peeling. When the anchorage length of CFS. But, in case of same anchorage length of CFS, when the strengthening amount of CFA is increased, the ductility is decreased. Therefore, it is considered that the anchorage of CFS in the end zone is necessary.

• Journal of the Korea institute for structural maintenance and inspection
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• v.2 no.2
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• pp.195-201
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• 1998

The purpose of this study is to evaluate the flexural strengthening effects of RC beams reinforced with carbon fiber sheets (CFS) in variable of strengthening amount and anchorage length of CFS. This study can be summarized as follows ; The CFS shares the tensile stress such as rebar during loading test. Also, as the strengthening amount of CFS is increased, the maximum flexural strength of RC beams reinforced with CFS is increased. Therefore, it is confirmed that the CFS's strengthening method is very effective to improve the flexural strength of RC beams. The maximum flexural strength of RC beams with CFS is determined by bond failure between CFS and concrete surface. So, the evaluation of CFS's strengthening effect can be calculated using the tensile stress of CFS which is peeling. When the anchorage length of CFS is increased, the ductility of RC beams is increased because of delaying the peeling of CFS. But, in case of same anchorage length of CFS, when the strengthening amount of CFS is increased, the ductility is decreased. Therefore, it is considered that the anchorage of CFS in the end zone is necessary.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.185-188
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• 2008

Flat plate system has structural weakness such as punching shear. Punching shear resistance can be increase by using a lager column section and effective depth, higer concrete compressive strength, and more flexural reinforcement ratio. But using a shear reinforcement is most economical, enable, workable solution in flat plate. The slab with thickness smaller than 250mm can not perform effectively due to insufficient development length of shear reinforcement in the slab. In case of proposed reinforcements, since the shear reinforcements were installed between the top bar and the bottom bar, shear elements generated slip failure before they reached yield. strength. effect of anchorage strength were effective anchorage length, concrete strength, diameter of shear element and anchorage detail. considering effect of slab thickness and concrete strength, formula of K factor propose in thin flat plate slab. by considering effect of anchorage length and concrete strength, strength of shear reinforcement will be computed correctly in thin flat plate slab.

• Geomechanics and Engineering
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• v.31 no.6
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• pp.573-582
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• 2022

The geometry of the gravity-type anchorage changes depends on various factors such as the installation location, ground type, and relationship with the upper structure. In particular, the anchorage geometry embedded in the ground is an important design factor because it affects the pull-out resistance of the anchorage. This study examined the effect of four parameters, related to anchorage geometry and embedded ground conditions, on the pull-out resistance in the gravity-type anchorage through two-dimensional finite element analysis, and presented a guide for major design variables. The four parameters include the 1) flight length of the stepped anchorage (m), 2) flight height of the stepped anchorage (n), 3) the anchorage heel height (b), and 4) the thickness of the soil (e). It was found that as the values of m increased and the values of n decreased, the pull-out resistance of the gravity-type anchorage increased. This trend is related to the size of the contact surface between the anchorage and the rock, and it was confirmed that the value of n, which has the largest change rate of the contact surface between the anchorage and the rock, has the greatest effect on the pull-out resistance of the anchorage. Additionally, the most effective design was achieved when the ratio of the step to the bottom of the anchorage (m) was greater than 0.7, and m was found to be an important factor in the pull-out resistance behavior of the anchorage.

• Journal of Conservation Science
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• v.28 no.2
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• pp.141-151
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• 2012

It was the 1900s that the damaged materials of stone heritages began to be preserved and managed for the purpose of reuse, especially since cement, an inorganic material, began to be used during the Japanese colonial period. Epoxy resin, an organic material, was introduced to architecture around the turn of the 1990s, and has been being used across the board. In particular, filler mixtures began to be aggressively used for the structural reinforcement of severed materials. The problem was metal stiffeners used for structural reinforcement. The anchorage length varied depending in different conservation scientists, and as a result the secondary damage was apt to occur in the materials. In this study, hereat, a calculation was made of the most effective anchorage length with the minimization of material damage. The results were as in the following: the anchorage length of an 8-milimeter-across (ø8) metal stiffener was found to be most effective at 60.88mm. Those of ø12 and ø16 were 60.88mm and 91.32mm respectively. In the case of other calibers, the anchorage length was calculated by a formula ${\ell}_d=a_tf_y/u{\Sigma}_0$. In the experiment, helically-threaded round bars were used as metal stiffeners in order that they could bear surcharge loads such as bending, shear and constriction.

• Journal of the Korean Society of Safety
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• v.29 no.5
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• pp.67-73
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• 2014

Construction equipment such as tower crane should be installed in a field without appropriate anchorage to cause a collapse of crane. The anchorage capacity can be varied with Anchor length, concrete strength, anchor diameter, hooked or non hooked these variables will be made and tested in the study. It is shown what anchorage capacity will be more effective case by case. Hooked and non-hooked rebar anchor concrete weight with dia 22mm rebar are shown with initial displacement at 170~220KN of hooked case and 200~210KN of non-hooked one which are linearly increased, without any ductility behavior with almost brittleness. Three(3) same test pieces are almost similarly behaviored without relation to hooked or non-hooked cases. It is found out that the bigger diameter of rebar becomes, the more resistant capacity could be made, but conversely ductility against sudden collapse similar to brittleness becomes the more insufficient. It is also found out that dia 16mm rebar could be more effectively applied to heavy support weight at construction sites.

• Steel and Composite Structures
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• v.52 no.2
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• pp.165-182
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• 2024

Grouted sleeve splice (GSS) is an effective type of connection applied in the precast concrete structures as it has the advantages of rapidly assembly and reliable strength. To decrease the weight and cost of vertical rebar connection in precast shear walls, a light-weight sleeve is designed according to the thick-cylinder theory. Mechanical behaviour of the light-weighted GSS is investigated through experimental analysis. Two failure modes, such as rebar fracture failure and rebar pull-out failure, are found. The load-displacement curves exhibit four different stages: elastic stage, yield stage, strengthening stage, and necking stage. The bond strength between the rebar and the grout increases gradually from outer position to inner position of the sleeve, and it reaches the maximum value at the centre of the anchorage length. A finite element model predicting the mechanical properties of the light-weighted GSS is developed based on the Concrete Damage Plasticity (CDP) model and the Brittle Cracking (BC) model. The effect of the rebar anchorage length is significant, while the increase of the thickness of sleeve and the grout strength are not very effective. A model for estimating ultimate load, including factors of inner diameter of sleeves, anchorage length, and rebar diameter, is proposed. The proposed model shows good agreement with various test data.

• The korean journal of orthodontics
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• v.45 no.2
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• pp.95-101
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• 2015

The aim of this case report is to describe the treatment of a patient with skeletal Class III malocclusion with maxillary retrognathia using skeletal anchorage devices and intermaxillary elastics. Miniplates were inserted between the mandibular lateral incisor and canine teeth on both sides in a male patient aged 14 years 5 months. Self-drilling mini-implants (1.6 mm diameter, 10 mm length) were installed between the maxillary second premolar and molar teeth, and Class III elastics were used between the miniplates and miniscrews. On treatment completion, an increase in the projection of the maxilla relative to the cranial base (2.7 mm) and significant improvement of the facial profile were observed. Slight maxillary counterclockwise ($1^{\circ}$) and mandibular clockwise ($3.3^{\circ}$) rotations were also observed. Maxillary protraction with skeletal anchorage and intermaxillary elastics was effective in correcting a case of Skeletal Class III malocclusion without dentoalveolar side effects.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.393-398
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• 1999

The main objective of this project is to define the ultimate bond performance of domestic prestressing strands in the precast prestensioned concrete beams. Eight specimens from four different companies were fabricated and tested in this study. Four-point loading tests were performed on the beams of domestic strands with an arbitrary anchorage length. The research has shown, that all seven specimens except one failed in bond are capable of developing their full flexural capacity and the strands within them are fully anchored even with the sudden transfer of frame cutting. Following results are summarized from the tests conducted. 1) All of the specimens are tested at an embedment lengths much shorter than those required by the ACI code, failed in flexure except one failed in bond. 2) It seems that the beam depth can not be an effective variable to estimate the bond length within these sections and length of specimens on this tests. 3) The development length with the stirrup space which are considered for correction factors in the equations of Russel and Paulsgrove, is fully accurate to determine the required length for the beam tested in this research.