• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.38-41
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• 2006

Wheel load fatigue experiment is carried out on a FRP-concrete composite deck. In FRP-concrete composite deck, FRP plays a role of a main tensile member as well as a permanent formwork and concrete plays a role of a main compressive member. Wheel load fatigue experiment, which shows more realistic behavior than pulsating fatigue experiment, is selected as a fatigue performance evaluation method. Until 1,000,000 cycles of loadings, load resistant performance is maintained without any loss, while residual deflection is increased.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.309-312
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• 2006

In this study, the repair method using PVA fiber reinforced mortar evaluated on durability performance. Test items are compressive strength, flexural strength, carbonation, freezing-thawing. As for the test results, it was found that durability performance of the repair method using PVA fiber mortar showed more better than the existing repair method. Therefore, appling on the repair method using PVA fiber mortar, the repaired concrete structures can be increased to service life.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.45-50
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• 1993

This paper describes some results of various tests which were carried out with varying the fineness of salg from 6000 to 10000$\textrm{cm}^2$/g and the slag content in cement from 30 to 50wt% for the perpose of utilizing finely ground blast-furnace slag as an ingredient for high-performance concrete. Test for heat of hydration, microstructural and hydration characteristics in paste, and fluidity and compressive strength in mortar were carried out. From these test results, it was found that, by properly determining the content and fineness of the slag, it is possible to manufacture high-performance concrete that has low heat of hydration, high early strength development, fine pore size and a highly densified microstructure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.30-31
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• 2016

Recently in the construction site is required various performance of mortar to deal with reliability, economy. Especially of environment-friendly, saving resources and high performance of mortar it began to require improvement of performance. Therefore, in this study, a series of tests was designed to develop a using mud flat mortar in view of the high absorption rate of tidal flats, to fix the water cement ratio to 70%. The mixing ratio were 10:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6 of fine aggregate and mud flats. Compared the flow value, chloride content, compressive strength, tensile strength, and workability of fine aggregate the substituted mud flat mortar and basic cement mortar, present the basic data on the characteristics and effects of mud flat mortar.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.77-80
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• 2006

This study investigated filling performance of concrete which can pass between reinforcing bars and be fully filled, and examined fundamental properties of concrete which is before or after hardened state, in response to maximum size of coarse aggregate. This study was also originally intended to find out one of the method that can improve concrete quality, using crushed coarse aggregate. Test showed that passing ratio of concrete decreased as aggregate site increased and as space between reinforcing bars decreased. In addition concrete using bigger size of coarse aggregate exhibited slightly higher compressive strength and showed lower length change ratio of drying shrinkage.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.275-276
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• 2018

Ultra high performance concrete(UHPC) represents high early age autogenous shrinkage strain due to its low water-to-binder ratio(W/B) and high fineness admixture usage. It has been reported that fiber can control restrained tensile stress and crack. The purpose of the present study is, therefore, to investigate the autogenous shrinkage as well as mechanical properties including compressive strength, flexural strength and modulus of elasticity on the UHPC with fiber type and pre-mix of binder.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.231-234
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• 2005

Steel braced frames retrofit method has been broadly used due to their effectiveness in both light weight and construction periods. However, steel braced frames retrofit method has difficulties in application on the inner frames of buildings to be retrofitted consequently, there have been demands for the braced frames retrofit method that can be broadly and easily applicable to both inner and outer frames of the buildings. The objective of this study is to develop and evaluate the seismic retrofit method applicable to the inner frame also by dividing the reinforcing frames into three unit. From the cyclic test of specimens, the test results dearly showed that steel brace using HPFRCCs and steel bars ensure the better cyclic compressive performance than the normal braced members.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.63-64
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• 2019

Due to the rapid deterioration of the domestic atmosphere, people are suffering from inconveniences such as wearing fine dust masks all the time during outdoor activities. In this study, light transmitting concrete, LEFC(Light Emotion Friendly Concrete), using TiO2 photocatalyst was produced. Since the characteristics of LEFC where acrylic rods are inserted require self-consolidating performance, the purpose was to utilize UHPC(Ultra High Performance Concrete) materials to obtain high-flowability. Further, the compressive strength and flexural strength were evaluated to prevent the reduction of epidemiological performance by utilizing UHPC materials. As such, a basic study was carried out to develop LEFC materials using photocatalyst that can purify the air and stimulate human sensibility.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.33-36
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• 2011

Recently, It has increased to use ultra high strength concrete. It is effective to mix organic fibers for preventing spalling. But if fiber mixed, flowability of concrete is decreases. The aim of this study is to evaluation of fire resistance performance for fiber-mixed ultra high strength concrete on field application. As a result, flowability of nylon fiber mixed concrete is better than polyethylene fiber mixed. In non-fiber and polyethylene fiber mixed concrete, spalling occurred. And strain converged at 0.004. Also, residual strength could not evaluate. Nylon fiber mixed concrete is effective to prevent spalling. And it remians 50% residual strength compare with compressive strength at room temperature.

• Computers and Concrete
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• v.17 no.6
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• pp.815-829
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• 2016

This study has been carried out to investigate the effect of the surface properties of Portland cement, diatomite and zeolite on the performance of concrete composites. In this context, to describe the materials used in this study and determine the properties of them, chemical, physical, mineralogical, molecular, thermal, and zeta potential analysis have been applied. In the study, reference (Portland cement), 10%-20% diatomite, 10%-20% zeolite, 5+5%-10+10% diatomite and zeolite were substituted for Portland cement, a total of 7 different cements were obtained. Ultrasonic pulse velocity, capillary water absorption and compressive strength tests were performed on the hardened concrete specimens. Hardened concrete tests have been done on seven different types of concrete, for 28, 56 and 90 days. As a result of experiments it has been identified that both the zeolite and diatomite substitution has a positive effect on the performance of concrete.