• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.1
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• pp.217-225
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• 2003

Grouting internally with grout materials can repair the micro-cracks and micro-voids of construction joints more efficiently than injecting grouts from the surface of cracks. A new internal grouting method using perforated bundled-cables was developed in this study to enhance the structural integrity of the construction joints. The extensive experiments were performed to examine the mechanical behavior of construction joints which are repaired internally by the developed method. The tests were conducted for rectangular-shaped box wall structures and straight wall structures. The strength and permeability tests at grouted construction joints were conducted to evaluate the structural behavior of repaired construction joints. The present study indicates that the internal grouting method developed in this study enhances greatly the performance of construction joints and may be efficiently used for the leak-tight integrity of construction joints in concrete structures.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.799-804
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• 2000

The joint treatment of concrete is one of the technical problems in top down construction method. Joints created wit the top down construction result in serous weakness from the aspects of both structural and water-barrier function. Several case studies for the insepction of top down construction joints of column in SRC structure using radar and infrared thermography method. The advantages and limitations of these methods for non-destructive inspection in top own construction joints are investigated.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.811-816
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• 2000

The joint treatment of concrete is one of the technical problems in top down construction method. Joints created with the top down construction result in serious weakness from the aspects of both structural and water-barrier function. Ultrasonic method was used for the inspection of top down construction joints of column in SRC structure in this study. As a result it has been verified that the semi-direct measurement method is more effective than the other methods for detecting the voids of construction joints.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.279-284
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• 2002

Prestressed concrete(PSC) bridge structures with a number of continuous spans has been segmentally built in many countries. These methods include incremental launching method, movable scaffolding method, full staging method and balanced cantilever method. In these segmentally constructed prestressed concrete bridges, many construction joints exist and these construction joints are weak points in PSC bridges. The prestress force can be introduced prestress force continuously through the construction joints of PSC bridge superstructure using tendon couplers. The main objective of this study is to evaluate the structural behavior and ultimate flexural strength of construction joints in PSC girder bridge members. To this end, a comprehensive experimental program has been set up and a series of full-scale tests have been performed. Ultimate flexural strength of construction joint in PSC members with tendon couplers is decreased by approximately 10% for non-coupled members.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.142-143
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• 2022

In order to achieve structural performance such as rebar clear spacing in the reinforced concrete structure construction, coupler splicing joints are becoming common. To confirm the performance of rebar splicing joints, quality verification is being carried out through coupler specimen tests. However, it can be said that the required performance is reached only when the actual construction in the field is constructed under the same conditions as the coupler splicing joint specimen. Therefore, the problems and solutions of the coupler splicing joint construction of the actual field was investigated in this study.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.897-902
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• 2000

In most of large panel pre-cast concrete system, the narrow joints have inefficiency to assemble several panels and structural problems due to their complicated process after construction. To improve, practically, structural performance and inefficiency to assemble, the behavior and strength of new wide joints method should be investigated experimentally. The result is that the shear force of wide joints is similar to that of loop joints, or more than. It seems that the use of wide joints is the possible methods in a construction field.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.4
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• pp.290-295
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• 2000

The joint treatment of concrete is one of the technical problems in top down construction method. Joints created with the top down construction result in serious weakness from the aspects of both structural and water-barrier function. Ultrasonic method was used for the inspection of top down construction joints of a various column in SRC structure in this study. The advantages and limitations of this method for non-destructive inspection in top down construction joints are investigated. As a result, it has been verified that the semi-direct measurement method is more effective than the other methods for detecting the voids of construction joints using ultrasonic method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.200-201
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• 2021

According to the dispute cases filed for claiming the collective defect repair fees, inter-layer concrete joints turned out to be the most frequently disputed item. For this reason, this study selects the inter-layer concrete joints to further analyze the primary causes and details of each dispute case. From the results of this study, three primary causes of the disputes are found, which are 1) the absence of standard specifications for construction quality control and management after construction; 2) the absence of established standards for repair when construction defects are found. In order to prevent construction defects in inter-layer concrete joints, this study provides three suggestions including 1) the current standard specifications for inter-layer concrete joints should be further specified by the Ministry of Land, Infrastructure and Transport; 2) a construction defect should be judged according to the compliance to the standard specifications; and 3) a clear and institutional protocol needs to be established for defect repair in cases that new public apartment houses have been judged to have defects.

• Advances in Computational Design
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• v.4 no.4
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• pp.343-365
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• 2019

Among the themes related to earthquake countermeasures at construction sites, those for tower cranes are particularly important. An accident involving the collapse of a crane during the construction of a skyscraper has serious consequences, such as human injury or death, enormous repair costs, and significant delays in construction. One of the causes of deadly tower crane collapses is the destruction of the site joints of the tower crane mast. This paper proposes a new design method by static elastoplastic finite element analysis using a supercomputer for the design of the end plate-type tensile bolted joints, which are generally applied to the site joints of a tower crane mast. This new design method not only enables highly accurate and reliable joint design but also allows for a design that considers construction conditions, such as the introduction of a pre-tension axial force on the bolts. By applying this new design method, the earthquake resistance of tower cranes will undoubtedly be improved.

• Journal of the Korea Concrete Institute
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• v.15 no.3
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• pp.425-432
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• 2003

The joint treatment of concrete is one of the technical problems in concrete constructions. Joints created with concrete constructions result in serious weakness in the aspects of both structural and water-barrier function. The radar and the infrared thermography method have been used for the non-destructive inspection of several construction joints of concrete structures in this study. The advantages and limitations of these methods are investigated for non-destructive inspection on construction joints of concrete columns. It can be shown that the detecting precision of construction joints using these methods is improved if radar analysis is carried out with a simulation analysis. In case of the infrared thermography method, the shape of construction joints can be also detected when heating is performed before testing. As the result, it has been verified that the construction joints, difficult to be detected by visual inspection, could be inspected effectively in broad areas at short period of time when these two methods are applied.