• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.508-513
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• 1996

The purpose of this paper, having chosen the connection method, filled by High-strength mortar, in conncetion of PC member, is to study the mechanical behaviour and practical usage of the method. The paper estimates the connection ability of Reinforced-bar, that is, Sleeve considering the effect of Reinforced-bar's dimeter. Sleeve's length and diameter in the structural behaviour of mortar-filled connection, therefore the behaviour of Splice-Sleeve exists in concrete practically. This paper discusses the effect of the concrete in Splice-Sleeve. Also, to estimate structural behaviour in a practical wall panel, the upper and bottom wall panels are produced and the behaviour of Splice-Sleeve is discussed. And then Vertical Tie Bar being designed by using Precast method, this paper presents the various application and the practicable method using Splice-Sleeve.

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.262-269
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• 2023

Purpose: In this study,fire-resistance test were executed to evaluate the effectiveness of the fireproof panel attached to the PSC slab in tunnel. Method: For the fire resistance test, the RWS curve was applied and the furnace of the KICT was used. Result: As a result of the experiment, the maximum temperature measured on the concrete surface of the PSC slab with the fireproof panel was 321.8℃, which was lower than the damage limit temperature of 380℃ for concrete. Also, at the t=25mm, the maximum temperature was 35.2℃, which was lower than the damage temperature of steel, 250℃. The use of precast fire resistance panel(t=30mm) improves fire resistance of PSC structures. Conclusion: As a result of the test, a reinforcement method for attached a fireproof panel in case of fire in a tunnel or an underground roadway is provided to protect a structure from fire. In the future, it is necessary to perform the static performance test of the slab to which the fireproof panel is attached, and to confirm the adhesion performance of the fireproof panel by performing the pull-off test and the fatigue test.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.4
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• pp.477-483
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• 2019

Recently, precast type SCP modules are being used instead of PSC structures in order to reduce the construction period and costs of special structures such as nuclear power plants and LNG storage tanks. The inside of the SCP module is connected with a stud for the integral behavior of the steel and concrete, and the use of high fluidity concrete is required. High fluidity concrete generally has a high content of binder, which leads to an increase in hydration heat and shrinkage, and a problem of non-uniform strength development. Therefore, in this study, fluidity and passing performance of high fluidity concrete according to material properties are investigated to select optimum mix design of low binder based high fluidity concrete. Mechanical properties of high fluidity concrete before and after pumping are examined using pump car. The filling performance of SCP mock-up members was evaluated by using high fluidity concrete finally.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.345-349
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• 2019

In Korea, the mountainous area occupies more than 70% of the whole country, cutting of earth slope that cuts a part of the ground surface is widely used when building infrastructures such as road, railroad, and industrial complex construction. In recent years, regulations on environmental damage have become more strict, and various methods have been developed and applied. Among them, Concrete-Panel Retaining Wall technique is actively applied. Concrete-Panel Retaining Wall is a method to resist horizontal earth pressure by forming a wall by attaching a precast retaining wall to the front of the support material and increasing the shear strength of the disk through reinforcement of the support material. Soil nailing, earth bolt, and ground anchor are used as support material. Among them, ground anchor is a more aggressive reinforcement type that introduces tensile load in advance to the steel wire, and a large concentrated load acts on the front panel. This concentrated load is a factor that creates cracks in the concrete panel and reduces the durability of the retaining wall itself. In this study, steel pipe sleeves and reinforcements were purchased at the anchorage of the panel to prevent cracks, and by applying bumpy shear keys to the end of the panel, the weakness of the individual behavior of the existing grout anchors was improved. The problem of degraded landscape by exposure to front concrete of retaining wall and protrusion of anchorage was solved by the production of natural stone patterns and the construction of sections that do not protrude the anchorage. In order to verify the effectiveness of anti-crack sleeves and reinforcements used in the null, indoor testing and three-dimensional numerical analysis have been performed, and the use of steel pipe sleeves and reinforcements has demonstrated the overall strength increase and crack suppression effect of panels.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.21-24
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• 2005

In this study, new methods of PC panel connection using 'ㄷ'type steel connection is proposed for highly seismic zone. A study was carry out to investigate the connection behavior subjected to cyclic inelastic loading. Three planar type and two T type PC wall will be tested. The variables will be examined were the shear reinforcement existence of top and bottom walls. The specimens will be tested only reverse cyclic loading in accordance with a prescribed displacement history. To transfer the shear strength shear key set up between top and bottom wall. Failure mode, behavior, ductility and energy dissipation capacity of the specimens constructed by new connections wll be compared with those of monolithic walls and Han's(Han, Jun Hee, Seoul National University) model.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.217-222
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• 2000

A large Pc structure building is system that consisted of bearing wall and slab joint. It has general structure stability from unity thar each members tied at joint. The strength of mortar that packing in joint among panels is important to internal force in entire building system. Do, if we could get early strength estimation with microwave. It would bring good construction planning, reduce construction time, and judge building stability and so on. The purpose of this study is to develop early estimation method for making better quality control and constructing good PC panel structure. The results of this study were as follows :1) With sealed molds, reduced moisture volatilization to more than 60% and enlarged 30% accelerated compressive strength than before one. 2) To get more accelerated strength, we should control maximum temperature difference to $30^{\circ}C$ downward 3)Interrelation with 7-day and 28-day strength were 0.831,0.902, and it is above than before one

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.749-754
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• 1997

Nowadays domestic building market has undergone several changes. Labor costs are too high and materials are in short supply. These raised building costs and therefore lowered productivity. At this point it is the best way to reduce manual labor and find alternative materials that can improve productivity. In the building process form work take the most part of it. So many formwork systems were developed to reduce the construction period and labor cost. But their technical improvements just limited to adjust form shape-the role of form is not changed. This research developed a new formwork systems that can function to unify or minimze the unit process with cast-in-place type permanent form. In former study (reported in '97 spring seminar), we did the assembling test with column and beam clamps. Furthermore, In this paper, we examined the total systems of form erections and evaluated the structural performances.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.6
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• pp.105-112
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• 2019

This study was conducted to examine experimentally the seismic performance of non-ductile reinforced concrete (RC) frames retrofitted with precast(PC) engineered cementitious composite (ECC) wall panels. The seismic performance was investigated through cyclic load tests on RC frame with different aspect ratio (h_w/l_w = 2 and 3) and installation position (center and both side of RC frame) of the PC ECC wall panels. Test results indicated that the seismic strengthening method using PC ECC wall panels is effective to improve significantly the strength, stiffness and energy dissipation capacity of non-ductile RC frame. Based on test results, it can be recommended to install PC ECC wall panel at the center of RC frame for improving the strength and to install slender wall panels at both side of RC frame for increasing ductility.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.3
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• pp.167-174
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• 2008

The objective of this study is to verify whether the composite action is sufficiently strong to withstand at the interface and the structural behavior of LB-DECK panel with field concrete slab strengthened with main reinforcing bars. Static and fatigue tests are performed for LB-DECK panels with varied shapes and amounts of rebars, and the results are compared with those of field concrete panel(FCP). The test results indicate that the LB-DECK panel with 1.5 times of more rebars inside significantly increase the overall stiffness. LB-DECK penel usually shows on average 52.1 percent of improved stiffness compared with the FCP. The fatigue test results also show that the LB-DECK panel can withstand two-million cycles of repeated loads without any damage.

• Advances in concrete construction
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• v.6 no.1
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• pp.1-13
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• 2018

An experimental investigation has been carried out on the use of an environmentally sustainable material, bamboo, in the construction of precast concrete structural wall panels. The strength and behaviour of three prototype bamboo reinforced concrete wall panel specimens under two-way in-plane action was studied. The specimens with varying aspect ratio and thinness ratio were tested to fail under a uniformly distributed in-plane load applied at an eccentricity of t/6. The aspect ratio of the specimens considered includes 1.667, 1.818 and 2 and the thinness ratio includes 12.5, 13.75 and 15. The influence of aspect ratio and thinness ratio of bamboo reinforced concrete wall panels, on its strength and behaviour was discussed. Varnished and sand blasted bamboo splints of 20 mm width and thickness varying from 8 to 15 mm were used as reinforcement in concrete. Based on the study, an empirical equation was developed considering the geometrical parameters of bamboo reinforced concrete wall panels for predicting its ultimate strength under two way in-plane action.