In this study, the hydration heat of cementless mortar containing FGD gypsum is investigated experimentally. According to research results, it was found that using cementless binder is more convenient to apply to secondary product of concrete than ordinary portland cement.

In this study, KS F 2405 was used to investigated the compressive strength of property of high performance concrete (HPC) using the fly ash and silica fume. The experiments were carried out silica fume-binder ratio from 5% (SF5) and fly ash 25%+silica fume 5% (FA25SF5). The compressive strength of HPC determined on 7days and 28days.

This research was intended to confirm the reducing effects water leakage of the acicular thaumasite as admixture for mixing concrete structure, in case of the water leakage on underground structure

This paper addresses the tensile strength of high performance concrete with fly-ash, silica fume. Test variables of this study is replacement ratio of admixture. Test results showed that 7 days tensile strength of specimen SF5 is higher than that of specimen FA25SF5. However, 28 days tensile strength of specimen SF5 and FA25SF5 had similar value.

Quality of injection sealer for water leakage maintenance be being managed by KS and ISO. However,the test result of bonding performance on the wet surface of concrete have some errors by an experimenter. Therefore this revision standard of test method is proposed by that the new tester is manufactured for solving this errors in this study.

This study presents a new estimation method for cable tension considering the initial deflection, the natural frequency changing, and the initial curvature shortening of an oscillating cable in the existing estimation formulas. The re-estimation for the cable-stayed Alamillo Bridge in Spain shows that the new procedure estimates tension force of the cables more accurately.

The objective of this study is to investigate the elasticity of high performance concrete replacement blast furnace slag. Experimental variables of this study are modulus(100×100mm, 150×150mm). And test results were compared with existing equations.

In this study, KS F 2438 was used to investigated the modulus of elasticity of high performance concrete (HPC) of replacement fly ash, and test results were compared with existing equations. Korea, America and Japan have to use cylinder specimens by KCI(2011). However, in this study was used cubic specimens and the experimental variable of this study is size of cubic specimens.

As Concrete is construction materials which is unevenly mixed with cement, aggregate and water, compressive strength and modulus of elasticity is an important factor to seize movement of structures. The purpose of this study is to investigate a correlation compressive strength and modulus of elasticity according to the size of structures, and also to analyze and compare to prediction equation of many countries.

Reinforced concrete coupled shear wall systems in medium and high-rise construction, where RC beams couple two or more RC walls have been frequently used. The objective of this study is to investigate seismic performance of coupling beam with headed bar.

Coupling beams of coupled shear wall systems are often the most critical members in medium or high rise buildings subject to seismic load or wind loads. To ensure the survival of shear walls under high-intensity cyclic loading, these beams, which normally have limited dimensions, should possess high deformability and good energy absorption while being able to resist large shear force. Experimental work are conducted to illustrate the design of special RC coupling beams using the proposed procedure reinforcement details.

The coupling beams provide transfer of vertical forces between adjacent shear walls in coupled shear wall system, which creates a frame-like coupling action that resists lots of the total overturning moment induced by the wind load or seismic load. The purpose of this study is to investigate the strain characteristics performance of coupling beams with headed bar.

복합 병렬 전단벽(Coupled shear walls)은 커플링 보와 철근콘크리트 벽체로 구성되어 바람이나 지진 등의 횡하중으로부터 유발된 전도모멘트의 상당 부분을 철골 연결보의 커플링 작용에 의하여 골조 작용(Frame action)을 의하여 횡력에 효율적으로 저항하게 된다. 본 연구에서는 접합부 상세에 따른 복합병렬 전단벽의 접합부 강도에 대한 규준식을 정립하기 위한 선행연구로서 병렬 전단벽 접합부에서 커플링 보의 매립길이 및 벽체 두께를 주변수로 실험적 연구를 수행하여 접합부 상세에 따른 복합 병렬 전단벽 시스템의 거동특성을 규명하고자 하였다. 본 실험결과, 실험체의 거동 및 내력은 매립길이 및 접합부 상세에 많은 영향을 받는 것으로 나타났으며 향후 설계시 이에 대한 영향을 반영해야 할 것으로 판단된다.

The objective of this study is to investigted the mechanical properties used cement mix-materials, blast furnace slag. Experimental variables of this study are replacement ratio of blast furnace slag.

The objective of this study is to investigate the behavior and strain characteristics of steel coupling beam-wall connection. Test variable of this study is embedment length of steel coupling beam in the embedment region. The results showed that Specimens PSH2C-ST and PSH2C-ST experienced bearing failure, based on the observation of strain of concrete in the embedment region.

Fly ash dumped generally pollutes environment in the world. With the aim of sustainable development, the contribution of fly ash in concrete to the mechanical properties should be investigated. Variation of the modulus of elasticity of concrete is an important factor to evaluate the performance. In this study, the experiments were carried out over water-binder ratios of 0.34 and fly ash-binder ratios from 0% to 30%. The elasticity of modulus of high performance concrete replacing fly ash were determined on 7days and 28 days.

The objective of this study is to investigate the failure modes of steel coupling beam-wall connection. Test variable of this study is types of material used, concrete and with pseudo strain hardening cementitious composites (PSH2C). The results showed that Specimen PSH2C-SB with longer embedment length of steel coupling beam exhibits good seismic performance than Specimen HCWS-SB.

The objective of this study is to investigate the seismic performance of hybrid coupled shear wall connection with new toughness material, pseudo strain hardening cementitious composites (PSH2C). Test variable of this study is the embedment length of steel coupling in connection region. The results showed that Specimen PSH2C-ST with longer embedment length of steel coupling beam exhibits good seismic performance than Specimen PSH2C-STE.

Despite the fact that wireless sensor is needed to be activated in order to do efficient and continuous management, batteries are limited on their lives in case of wireless sensor. This paper suggests that the energy harvester model can be used within low frequency and examined using single crystal PMN-PT material which is definitely good at the efficiency of piezoelectric in order to maximize the output power. And the possibility of wireless sensor node power supply is verified by using an acceleration data of cable hangers of YoungJong Grand Bridge.

본 연구는 쌈채소로 각광받고 있지만 산림에서는 희귀한 식물이며 번식이 까다로운 병풍쌈(Cacalia firma)을 기내 번식을 통한 식물체 번식을 위하여 진행되었다. 병풍쌈의 기내 종자발아를 위해서는 종자의 절단 및 GA3처리가 효과적이었다. 종자유래 유식물체의 자엽, 잎, 엽병 및 뿌리절편을 BA가 첨가되 배지에 배양한 결과 엽병 절편당 2.76개로 가장 양호하였다. 부정아 유래 식물체의 엽병 절편을 다양한 종류의 cytokinin(2-iP, kinetin, zeatin, TDZ, 및 BA)를 각각 2 mg·L-1씩 단독 첨가한 배지와, 오옥신으로 NAA 0.5 mg·L-1을 혼합 첨가한 배지에 접종하였다. 그 결과 TDZ와 BA에서 높은 부정아 유도율을 나타냈고, kinetin에선 낮은 부정아 유도율을 보였으며, 2-iP와 zeatin에서는 부정아가 형성되지 않았다. NAA를 혼합한 배지는 단독 처리 배지보다 높은 유도율을 나타냈지만 배양절편당 부정아의 수는 오히려 줄어들었다. 대부분의 부정아는 cytokinin 단독 처리시 배양절편으로부터 직접부정아가 발생되었으며, cytokinin과 NAA 혼합된 배지에서는 일부 캘러스화된 부분에서 부정아가 발생되었다. 이들 부정아는 IBA가 첨가된 배지에 옮겨준 경우 뿌리가 발생되어 식물체로 재생되었다. 재생된 식물체는 토양에 성공적으로 순화되었다.