• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.47-50
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• 2008

This study analyzed the effect of increasing the number of times using aluminum form to the surface quality of concrete through small sized test, and the result was summarized as following. At the early stage, there was no remarkable change between aluminum and coated plywood form, and the surface quality of concrete both forms slightly declined corresponding with increasing the number of times using.As void on the surface corresponding to the number of times, the voids ranged 0.1~1mm were increased corresponding to increasing the number of times using forms, and the other range voids were also increased according to increasing the number of times using forms. It was confirmed that the surface of concrete was damaged gradually. For comparison with aluminum and coated plywood form though this experimental results, there might be no difference, if release agent was used properly.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.853-858
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• 2000

According to the results of this research, Production of Fold Mortar Permanent - Form was found to be possible by Mortar. Th FP-Form (Fold Permanent-Form) mortar had compress strength 580kgf/$\textrm{cm}^2$. FP-Form model was made by the result of the first research. There was no minute-crack on beam form and the outer surface of form was very smooth, and those qualities it were made possible hand-mad by experiment. This study is about bond strength progress of FP-Form that developed for the form work rationalization and systematization. The result of this study follows; (1) Fluidity and strength development of mortar which used for FP-Form are satisfied (2) After study on getting good bond strength progress, inside-uneven type presents the better suitableness, and wire netting V-type presents the better shear strength.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.107-108
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• 2016

When the construction in a low temperature, the concrete performance is deteriorated by frost damage at early age. In this study, the form utilizing heating sheet and insulation is measured the performance to prevent frost damage at 10 below zero. It produced five types of the form and to measure the temperature history and compressive strength. At first, form attached heating sheet showed the highest temperature. But the form attached vacuum insulation showed the highest temperature ever since 12hours. In the case of compressive strength, the form attached heating sheet + isopink(polystyrene foam board) showed the highest compressive strength. It was followed by vacuum insulation. As a result, the form utilizing insulation and heating sheet helped to prevent frost damage.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.83-84
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• 2019

Free-form buildings refer to geometric external structures in curved form, unlike conventional structures with straight lines. The development of construction technologies for the implementation of these Free-form buildings is ongoing. However, there are still many restrictions on the construction technology of Free-form buildings, resulting in problems such as increased construction period and increased construction costs. Therefore, it is urgent to develop building technology for the construction of Free-form building in order to secure competitiveness in the global Free-form building market. Accordingly, this study proposes Two-sided multi-point press technology that can solve problems of existing technology and implement FCP(Free-form Concrete Panel).

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.356-362
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• 2016

Light-weight concrete uses forming agents for reducing weight and high heat insulation property. However, the forming agents make problems of decreased volume and compressive strength of the concrete. This research aims to having weight-reduction and securing heat insulation property using recycled wasted form polyurethane without any forming agents. A small quantity of admixture used for constructability and avoiding material segregation. We picked admixtures from two different companies which shows evenly dispersed of wasted form polyurethane. This research conducts a study on the effect of mixing ratio of admixture on the light-weight concrete used wasted form polyurethane. As a result of the test, increased mixing ratio of the admixtures results reduced fluidity of concrete. On the other hand, percentage of moisture content and compressive strength are increased slightly. Combustibility performance and sound insulation performance are also secured, as well.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.614-617
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• 2006

This study investigates the quality control and the finishability improvement properties of durable marine concrete under construct in Geo-je Ka-duk fixed link project. Below $3.5\times10^{-12}m^2/s$ chloride migration coefficient and above 40MPa compressive strength are required for the caisson structure concrete. The quality control was performed from physical-chemical analysis of raw materials to concrete test. Also, the efficiency of vibration type and action interval were tested to remove the entrapped air on the faced to form. And kinds of form and remolding agent were also tested. This paper aim to enhance the practical use of high performance concrete to construction field.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.391-396
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• 1998

The concrete structures are hardly ever built under ideal conditions. So many defects may occur for a various reasons such as unsuitable and defective materials, construction methods, poor workmanship, particular structural form and prevailing weather conditions. Some structural form can greatly increase the risk of occurrence of defects. Therefore we investigated the actual condition of the deterioration factors for reinforced concrete apartment, which was composed of 85 apartments with various building ages in different regions with five evaluation the deterioration factors of apartment building to establish the overall evaluation system of deterioration degree for reinforced concrete apartment in Korea.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.601-604
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• 2008

When the concrete is placed, the water, needed for hydration of the cement, is under 30% of W/C including bound and gel water. However, as minimum water content cause bad workability, the W/C have to be higher. Therefore, fresh concrete produce 10${\sim}$20% extra water. As those water remain entrapped air in the concrete, life of the structure is reduced because of the degradation caused by entrapped air. For that reason, if extra water is eliminated, it will be great to improve the durability of the structures. Therefore, this study was performed to verity the fundamental properties through the experiment on the dewatering system using the euro form for eliminating extra water. When the dewatering form was applicated, the compressive strength was increased by 16% than those of normal form. However, the increasing rate of compressive strength got lower as the height is higher. In terms of ultrasonic pulse speed and surface roughness, the dewatering form showed better results than the normal one.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.969-972
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• 2008

This study investigated the effect of the fundamental condition such as release agent, form conditions and types to the surface of concrete with aluminum form on the various temperatures. On the observation with the naked eyes, coated plywood and aluminum form without a scratch showed similar result, and the surface quality of the concrete with aluminum form was gradually decreased corresponding to the increase of the temperature.For the surface roughness, there is no remarkable tendency according to the temperature. However, the difference in accordance with release agent occurred.As void on the surface corresponding to the various temperature, the micro voids ranged $0.1{\sim}1mm$ were increased corresponding to the increasing temperature, so it was confirmed that the chemical reaction wae accelerated. And the voids of the other range also increased. the fundamental condition such as release agent, form conditions and types

• Journal of the Korean Society for Railway
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• v.17 no.5
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• pp.365-372
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• 2014

Technologies for rapid concrete curing using elevated temperature are important for saving cost and time when constricting concrete structures. Recently, a microwave heating form was developed. In this study the early strength of concrete cured by the developed form was experimentally investigated. Large scale mock up tests were conducted six times, and the results were analyzed based on the maturity theory. Logarithmic correlation curves were generated based on the measured strength and estimated maturity. It was confirmed that the strength development of the concrete cured by microwave heating form can be estimated by the equivalent age theory usually applied to steam-curing technology. By using the microwave heating form, one day at most is enough to get the required strength for the safe removal of forms, even in cold weather.