• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2016.10a
• /
• pp.71-72
• /
• 2016

Most of studies on PC method aim at the structural analysis and development of PC members, and studies on the construction management aspect are insufficient. Therefore, this study tries to investigate 'hallow PC column composite method(HPC composite method)' from the viewpoint of construction management and analyze the construction cost of the composite method. On the assumption that each comparative method was applied to the zone, the difference in construction cost between the two methods was analyzed. As a result, HPC composite method increased the initial investment cost because of its factor technology, but reduced transport cost, lifting cost, and installation cost through lightweight columns. This study analyzed only the difference in construction cost of HPC composite method so that it has the limitation in evaluating its economy. Therefore, to evaluate the economy of HPC composite method, it is considered to research more the construction cost of HPC composite method.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.337-338
• /
• 2012

As a rahmen structure, the connection among columns of Green frame is divided into three types such as sleeve, coupler (column pre and post installation), and bolt. The bolt type consists of six types according to steel frame shape and each type has different constructability, safety, structural performance, cost, and quality. Therefore, the analysis of comparison among the types is necessary. The objective of this study is to analyze the characteristics according to the shape of six bolt types to select the appropriate connection of Green frame. The results of this study can be used as a basic study for indentifying the characteristics of steel frame on site applying bolt type connection of Green frame. In addition, this study can be applicable to compare and analyze the performance and constructability of six bolt types in detail.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.05a
• /
• pp.78-79
• /
• 2013

As a part of study to maximize the amount used of the ground granulated blast-furnace slag, the study deals with setting properties of paste that is mixed the ground granulated blast-furnace slag with CaO-Al₂O₃ based inorganic blinder. The results of the experiment show that the setting time is most fast in the mix of 25% rate of CaO-Al₂O₃ based inorganic blinder. It is generally needed 2 hours for work time in precast concrete products. In this study, this requirement is achieved when using the retarder of 0.5%.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.11a
• /
• pp.177-178
• /
• 2020

In the construction industry, expectations for the Precast Concrete(PC) construction method are rising due to demands for high quality and productivity and social and environmental issues. However, although technical problems that occurred in the early stages of technology introduction have been solved, research related to proper construction management for PC construction methods has been relatively neglected and the advantages of PC construction methods have not been fully utilized. In this study, each group involved in PC works was surveyed to identify important management tasks affecting productivity of PC works to improve PC contruction management system. Based on factor analysis, 22 tasks were calssified into 5 management groups. The results of this study will be used to present a framework for the application of automation and information technology to improve the productivity of PC works.

• Journal of the Korea Institute of Building Construction
• /
• v.14 no.6
• /
• pp.615-621
• /
• 2014

This study suggests the design and assembly drawing of the prefabricated precast concrete arch ammo magazines using the numerical analysis as well as the explosion verification test. The protective capacity of the proposed magazines is identified with the maximum support rotation angles measured by explosion verification tests according to the U.S. Unified Facility Criteria 3-340-02. Using numerical analysis, it is examined that oval-type members are better than the semi-circle ones in terms of protective capacity. Based on this numerical results, the design and assemble drawing for the prefabricated precast concrete arch ammo magazine are developed. It is identified that the structure constructed by invented design and assembly drawing has enough protective capacity against blast pressure caused by 133.75kg TNT explosion. The detonation point cannot be open due to the military security. In sum, it could be concluded that the ammo magazine proposed in this study has reliable protective capacity with enough redundancy. The redundancy means that there are more economic design approach with reducing the curved wall thickness.

• Journal of the Korea Institute of Building Construction
• /
• v.14 no.2
• /
• pp.156-162
• /
• 2014

This study aims to develop a rapidly hardening type of concrete to achieve the removal of form intensity (more than 10MPa) using the method of curing at room temperature in order to solve some economic environmental problems by omitting the steam curing process involved in producing PC (Precast Concrete). Therefore, this study evaluated a rapidly hardening cement containing a high amunt of C3S, which is very responsive in expressing early intensity, and a rapidly hardening type of concrete which uses some hardening accelerator to increase thehydration reaction of $C_3S$. The results of the experiment on concrete using some hardening accelerator are asfollows. In the slump flow experiment for identifying the liquidity and the air test, the desired values were met. The compression strength showed rapid expression response by 12 hours, and met the desired value within 6~9 hours. Its drying shrinkage value and Autogenous shrinkage value were measured as below ($-754.5{\times}10^{-6}$),and satisfied the requirements. In addition, in the Semi-Adiabatic Temperature Test, it was found that the concrete rose to its peak temperature within 24 hours and then its temperature dropped.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.23 no.5
• /
• pp.359-370
• /
• 2021

Duct slabs, which are used to build ventilation facilities in underground spaces with transverse ventilation system, need to secure fire resistance according to longitudinal and heavy vehicle traffic of tunnels. This study measured the temperature change at the construction joint of the precast fireproof duct slab which integrates fire resistance material and duct slab under the RWS fire scenario. As a result, it was confirmed that if there is no reinforcement of the construction joint, damage will occur in concrete inside the construction joint, leading to damage to the fireproofing layer. On the other hand, when one side of the construction joint was reinforced with fireproofing materials, it showed more than three times the fire resistance performance compared to when there was no reinforcement. At this time, cross-sectional losses of concrete and fireproofing layer were shown in blocks without reinforcement, but no damage was seen in the reinforced blocks.

• Journal of architectural history
• /
• v.9 no.3 s.24
• /
• pp.51-69
• /
• 2000

This study tries to analyze the development of architectural technologies appeared in several tall buildings and large spatial structures from 1955 to 1999 in Korea. We suppose that these buildings represent the development of technology in Korean modern architecture. By the detailed analysis of these buildings, we can arrive at a conclusion as such; During the years 1955-1999, there existed a great changement in the eighties. We can find this fact very well in the domain of structural system and curtain wall system. In large spatial structures, the structural-system of shell and steel truss dome was replaced by that of space frame, space truss and cable truss with membrane. In tall building, the structural system of rigid frame and shear wall was replaced by tubular system, core and outrigger system. Korean architects introduced the aluminum curtain wall in the sixties, but its low technological level caused many problems in reality. Therefore, precast concrete curtain wall appeared from seventies as the main method for an outer wall in tall building. With the augmentation of height after 1980, PC curtain wall was replaced by the aluminum curtain wall of unit type and structural glass wall system. These systems help to stress the transparency in a tall building.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2014.11a
• /
• pp.193-194
• /
• 2014

Green Frame is a building frame system composed of precast concrete columns and beams. For the construction to run smoothly, the quantity of frames should be estimated in the planning phase and a plan on production of members should be established in connection with the overall work plan. The algorithm for calculation of the amount of forms used in Green Frame automatically estimates the quantity of forms using the design structure prepared in the design phase. The number and area of forms are calculated using the member size drawn from the structure design. Based on the quantity calculated, the type and area per form size are estimated to be used in preparing BOQ (Bill of Quantity). Thus, the time required for architectural planning and design can be shortened when the algorithm for calculation of the amount of forms is applied. This study is on the basic research of calculating the quantity of forms using the structure design and of the algorithm for calculation of the amount of forms used for production of composite PC members.

• The Journal of Engineering Geology
• /
• v.26 no.1
• /
• pp.51-61
• /
• 2016

New building methods are needed to aid increased inner-city redevelopment and industrial construction. A particular area of improvement is the efficient use of cut slopes, with the minimization of associated problems. A retaining wall of precast panels can resist the horizontal earth pressure by increasing the shear strength of the ground and reinforcing it through contact with the panels. Precast panels allow quick construction and avoid the problem of concrete deterioration. Other problems to be solved include the digging of borrow pits, the disposal of material cut from the slope, and degradation of the landscape caused by the exposed concrete retaining wall.This study suggest the methods of improvement of an existing precast panel wall system by changing the appearance of the panels to that of natural rock and improving the process of adhering the panel to a vertical slope. The panels were tested in the laboratory and in the field. The laboratory test verified their specific strength and behavior, and the field test assessed the panels' ground adherence at a vertical cutting. Reinforcement of the cutting slope was also measured and compared with the results of 3D numerical analysis. The results of laboratory test, identified that the shear bar increase the punching resistance of panel. And as a results of test construction, identified the construct ability and field applicability of the panel wall system adhered to in-situ ground. In addition to that, extended measurement and numerical analysis, identified the long-term stability of panel wall system adhered to in-situ ground.