• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1990.10a
• /
• pp.91-94
• /
• 1990

The object of this study is to develop computer programs with which ordinary engineers can analyse or design steel-concrete composite teams using optimization technique. Various design ana construction techniques which could maximize load carrying capacities and control concrete tension cracks effectively are studied and included in the programs. Analysis results show that proposed construction techniques can reduce steel weight by about 10%∼20% compared with ordinary composite beam. Concrete tensile stresses can also be controlled affectively by the suggested techniques.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1997.04a
• /
• pp.186-190
• /
• 1997

Corrosion of steel reinforcement is the most significant factor of deterioration in reinforced concrete structures. It breaks down the passive film and allows the steel to be corroded severely at a high rate. The main object of this study is to determine the critical chloride ion concentrations in the pore solutions and chloride binding effect of cement pastes. It is found that binding chloride ion ratio of cement is between 0.04% and 0.3% and Cl/OH in pore solution under 0.3.

• Magazine of the Korea Concrete Institute
• /
• v.2 no.2
• /
• pp.93-99
• /
• 1990

The object of this study was to investigate the flexural stress blocks of High Strength Concrete Members under monotonic loading. Such a stress block should be clearly idealized before High Strength Concrete can be used with confidence in Structural Members. The principal test variables were the Compressive Strength of Concrete, the percentage of longitudinal reinforcement and the spacing of confinement reinforcement. The rectangular stress block of the present ACI Building Code was found to give acceptably conservative flexural strength predictions over the entire range of concrete strength from 280kg/crd (4Ksi)to 1050kg/crd( 15Ksi)

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.11a
• /
• pp.395-398
• /
• 2005

In recent years, the applications of high-strength concrete have increased, and high-strength concrete has now been used in many parts of the world. The growth has been possible as a. result of recent developments in material technology and a demand for higher-strength concrete in Korea. In this study, we have an object to produce the ultra-high strength concrete(Super-Con) of over 100MPa with low price materials. First, the binders for Super-Con should be selected by the tests; setting time of paste, flow value and strength of mortar. From the test results, the binders are blended with ordinary portland cement, pulverized portland cement and silica fume. Fundamentally the compressive strength, frost resistance and chloride resistance are investigated.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1998.04a
• /
• pp.161-166
• /
• 1998

The main object of this study is to examine the basic properties of fresh concrete as well as hardened concrete using several types of cement such as ordinary portland cement, sulphate resisting portland cement, blast furnace slag cement, ternary blended cement. In addition, effects of each cement on the durability including drying shrinkage, freeze-thawing resistance, resistance of chloride ion penetration, carbonation of concrete were investigated. As the results of this study, it was proved that most of the properties of concrete using each cement were similar, but there were some differences in bleeding, setting time, resistance of chloride ion penetration and carbonation.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.3 no.1
• /
• pp.113-120
• /
• 1999

Due to the heterogeneous nature of a concrete, periodic inspections are compulsory to maintenance of quality of concrete structures. The major object of this study is to analyze and investigate experimentally the experimental equation for the estimate of compressive strength of prestressed concrete. In this study, surface hardness method, ultrasonic method are investigated to evaluate strength of concrete specimens. Specimens are cast in laboratory and cores are cut from specimens in order to estimate the accurate strength. These values are used to compare with calculated values from test data. The result shows that the proposed equation can reproduce the results at prestressed concrete beam girders more appropriately than previous equations.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.9 no.1
• /
• pp.53-59
• /
• 2014

In multiple object tracking, accurate detection for each of objects that appear sequentially and effective tracking in complicated cases that they are overlapped with each other are very important. In this paper, we propose a multiple object tracking system that has a concrete detection and tracking characteristics by using multi-lateral histogram and SIFT feature extraction algorithm. Especially, by limiting the matching area to object's inside and by utilizing the location informations in the keypoint matching process of SIFT algorithm, we advanced the tracking performance for multiple objects. Based on the experimental results, we found that the proposed tracking system has a robust tracking operation in the complicated environments that multiple objects are frequently overlapped in various of directions.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1998.10a
• /
• pp.559-564
• /
• 1998

The object of this thesis is an analytical study on shear deformation of reinforced concrete members using monte carlo method. Using the established experimental data that has been presented in various documents the stress-strain relationships curves of reinforced concrete (300kgf/$\textrm{cm}^2$~400kgf/$\textrm{cm}^2$) models are proposed. Finally, the theoretical values calculated using the analytical method developed in this study have been investigated in comparison with the experimental ones which were carried out earlier in order to prove its validity. From the results it has been shown that theoretical values agree quite well with experimental ones, and it could be pointed out that the presented analytical method is widely acceptable for the practical analysis of shear displacement of reinforced concrete members.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.05a
• /
• pp.237-242
• /
• 2003

The object of this study is to investigate the strength development properties and the strength prediction of three-component concrete using the fly ash and the blast-furnace slag by a maturity method. The results were as follows. The values of the activation energy on this experiment are calculated as 38.69, 36.47, 32.46, 30.99 KJ/mol in the W/B 60, 55, 50, 45%. And it is considered that the equivalent age can be used to predict strength of the three-component concrete in the optional age. Also the strength of the three-component concrete can be predicted from the result of high correlation between predicted strength and measured strength.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.11a
• /
• pp.161-164
• /
• 2004

The object of this study is vibrating compaction and curing method in the production process of Design concrete for precast concrete(Design-PC) product. From change of vibrating compaction time and pre-curing time, curing temperature which would be factors of product quality in Design-PC concrete production, and research of optimized steam curing condition from relations between curing condition and strength development, basic data of vibrating compaction time and concrete steam curing method for Design-PC will be presented.