• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.11a
• /
• pp.175-176
• /
• 2018

In this study, the performance of acrylate was evaluated by using acrylate composite waterproof sheet. Through this experiment, the waterproof sheet plays a primary role of waterproofing. When the water leakage occurs, the acrylate reacts with water and expands, and the performance of the self repairing of the damaged part is confirmed by temperature.

• Journal of Korean Association for Spatial Structures
• /
• v.14 no.2
• /
• pp.41-50
• /
• 2014

The stone pagoda of Mireuk temple site is currently restoring through the repairing process. This stone pagoda has the various construction types in the inner and outer space. Therefore, the stress concentration and structural behavior need to be considered through the analysis of various construction patterns. To this end, this study presents the structural modelling and analysis considering the discrete element analysis technique to solve the discontinuum behavior between the stone elements. Also, this study performs the structural performance evaluation through the various design variables for the safety of stone pagoda. Through the analysis results, we can find out the small stress concentration in the several members. But, because the stresses and displacements are relatively small, we can secure the safety of the whole structure.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.11a
• /
• pp.223-224
• /
• 2017

In this study, various materials such as epoxy material, urethane material, cement material, and acrylic material are used to solve the water leakage occurring in underground structures. However, in the reality that the durability is insufficient and the effect is insufficient, it is aimed to improve the repairing effect by using cement and acrylics in combination. As a first study, we tried to verify the performance of improve the performance by checking the product properties according to the composition ratio of polyacrylic resin. Polyacrylic resin is evaluated in three different composition ratios. When the material is selected for polyacrylic resin, it is applied to the field to understand the maintenance effect and durability.

• Journal of Korean Society of Steel Construction
• /
• v.25 no.1
• /
• pp.81-92
• /
• 2013

The objective of conventional seismic design is to ensure an acceptable safety level while avoiding catastrophic failures of structures and loss of life. Over the last many years, a large amount of research has been devoted into developing effective earthquake resistant systems in order to raise the seismic performance level of structures. The purpose of this study is to propose a new damping system, which realize not only increasing seismic performance but also easy repairing after an earthquake. The proposed damping system is slit in the bottom of wall with damping devices installed in the slit horizontally aiming to dissipate energy during earthquakes. Cyclic loading tests were conducted to investigate hysteretic behavior and energy dissipation capacity. Test results show that the proposed systems exhibit a stable hysteretic response and the energy dissipation in this system is concentrated on the damping devices.

• International Journal of Concrete Structures and Materials
• /
• v.2 no.1
• /
• pp.27-33
• /
• 2008

Most of existing repair materials have some shortcomings such as brittle fracture, imperfect interface bonding and marked difference in modulus of elasticity compared with the structures. These problems make their repair inefficient. Some researches on using a fiber-reinforced mortar as an alternative to enhance the efficiency have been carried out recently. This paper presents the results of an experimental study on the performance of sprayed PVA fiber-reinforced mortar as a repair material. We evaluated its mechanical properties, durability and strengthening effect. This study shows that the sprayed PVA fiber-reinforced mortar is remarkably effective as a repair material.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.04a
• /
• pp.525-528
• /
• 1999

Structural walls have been favored for the design of reinforced concrete buildings in seismic zone areas because they provide an efficient bracing system and offer great potential for lateral load resistance and drift control. Loads on structures due to earthquakes are not unlikely to reach, if not exceed, the design load levels. Hence, structural damage to walls is inevitable, and it is necessary to repair this damaged walls. Yet, information on repair method and data related to the strength and deformation characteristics of repaired walls is limited. In this study, specimens which have their aspect ratios of about 1 to 3 will be repaired. For the repairing the damaged walls, new concrete and new reinforcing bar are replaced with cracked concrete and the buckled reinforcing bar, respectively. The objective of this study is to evaluate the performance of the repaired structural walls in the capacity of strength, stiffness, and maximum deformation comparing with the undamaged walls.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.343-346
• /
• 2005

This study makes the performance evaluation of water-jet chipping through analysis of ruggedness of chipping surface. The ruggedness is mapped by 3D Laser Scanner and the results are also compared with the chipping surface by mechanical chipping. And the details of in-situ works is investigated for increasing interface adhesion between existing concrete and repairing mortar. Water-jet has good operation efficiency which is up $60m^2$ per hour when the chipping depth is 7cm and also has a large ruggedness about 1.65.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05b
• /
• pp.517-520
• /
• 2006

The waterproofing of Building on the roof has been exposed more underground or the other part of waterproofing than environmental factor(solar heat, UV, salt, acid rain, wind, temperature, snow, rain, etc.) or physical factor. So it must be have a waterproofing performance and it has a special technique for the maintaining of concrete durability. Therefore, exposed waterproof layer has to protected from UV, solar heat, rain and the outside environment also, to endurance durability methods spread face plate topcoat material on the waterproof layer. But, actuality faceplate waterproof layer of topcoat materials are unbearable to UV, solar heat and moisture etc. and it doesn't have adhesion with waterproof layer in the middle. So it happens to crack, separating and heaving etc. Therefore, in the study, we will suggest that using of the exposed roof waterproof layer topcoat materials test method manage rooftop waterproof layer for the durability and the stability.

• Structural Monitoring and Maintenance
• /
• v.1 no.3
• /
• pp.323-338
• /
• 2014

In this study a new innovative method of earthquake-resistant strengthening of reinforced concrete structures is presented for the first time. Strengthening according to this new method consists of the construction of steel fiber ultra-high-strength concrete jackets without conventional reinforcement which is usually applied in the construction of conventional reinforced concrete jackets. An innovative solution is proposed also for the first time that ensures a satisfactory seismic performance of existing reinforced concrete structures, strengthened by using composite materials. The weak point of the use of such materials in repairing and strengthening of old R/C structures is the area of beam-column joints. According to the proposed solution, the joints can be strengthened with a steel fiber ultra-high-strength concrete jacket, while strengthening of columns can be achieved by using CFRPs. The experimental results showed that the performance of the subassemblage strengthened with the proposed mixed solution was much better than that of the subassemblage retrofitted completely with CFRPs.

• Journal of the Korean Institute of Educational Facilities
• /
• v.8 no.2
• /
• pp.5-12
• /
• 2001

As the exiting school facilities become old and unfit for new curriculum, the systematical remodelling process based on its educational and physical functions is required. due to the inadequate maintenance and repairing practices, unnecessary costs are expended. Therefore, this study aims to establish a remodelling decision-making model for improving the educational environment of the existing school facilities. According to the budget system, it proposes the concept of remodelling that includes the activities of extension, reconstruction, repair and improvement. This study classifies the performance evaluation for school facilities as that of safety, durability and educational function, and articulates the assessment standards, methods and elements. In the end, it suggests a rational model for remodelling decision-making that can provide efficient and comprehensive remodelling process, economic and sustainable school development.