• Computers and Concrete
• /
• v.21 no.3
• /
• pp.239-248
• /
• 2018

This study developed and investigated a precast slab track system partially reinforced with glass fiber reinforced polymer (GFRP) rebars in the transverse direction, which mitigated the loss of track circuit current by reducing magnetic coupling between the rails and steel reinforcements. An electric analysis was conducted and the results of the analysis verified that the GFRP rebars mitigate the reduced current strength produced by electro-magnetic induction. In the study, a three-dimensional finite element method and flexural experiments were used to study the mechanical behavior of the proposed slab track.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1996.03a
• /
• pp.165-171
• /
• 1996

Recently, to improve the productivity in the continuous casting process, thin slab continuous caster which is one of the new steelmaking technologies by a high speed casting has been introduced. In the process of the thin slab continuous cast, there is more possibility than convnetional one that the deformation be occurred by the bulging of solidified shell, since the thickness of soliidfied shell is very thin as much as 60mm after the casting is finished. In some cases of severe bulging, there might be more breakout. In this paper, using finite difference method , solification analysis of slab is made as well as the thicknessof solidified shell and temperature are calculated. Also, based on the data of the calculated temperature, the deformed behavior of solidified narrow face is anlayzed with the MARC which is a package program for finite element analysis.

• Structural Engineering and Mechanics
• /
• v.45 no.4
• /
• pp.455-470
• /
• 2013

RC flat plates that have no flexural stiffness by boundary beams may be governed by a serviceability as well as a strength condition. A construction sequence and its impact on the distributions of construction loads among slabs tied by shores are decisive factors influencing immediate and long term performances of flat plate. Over-loading and tensile cracking in early-aged slabs significantly increase the deflection of a flat plate system under construction. A reshoring work may be helpful in reducing slab deflections by controlling the vertical distributions of construction loads in a multi-shored flat plate system. In this study, a change of construction loads by reshoring works and its effects on deflections of flat plate systems under construction are analyzed. The slab construction loads with various reshoring schemes are defined by a simplified method, and the practical calculation of slab deflections with considering construction sequences and concrete cracking effects is applied. From parametric studies, the reshoring works are verified to reduce construction loads and slab deflections.

• 한국연소학회:학술대회논문집
• /
• 2004.06a
• /
• pp.67-74
• /
• 2004

Numerical analysis code has been developed for investigating the combustion characteristics in a slab heater of a steel mill company. Unsteady full 3-Dimensional behaviour can be predicted with the code. Premixed flame model is adopted for combustion phenomena. And eddy dissipation model is used for turbulent flow and non gray FVM method for radiation. Slab movement can be fully traced from entrance into heater until it's exit and computation is performed during that period. Code was validated by comparing the calculation results with experimental ones for the bench scale heater.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.05b
• /
• pp.91-96
• /
• 2011

The flat slab is well-known as a structural system to reduce the story height, so it is broadly used for recent building. However, the normal RC flat slab is not appropriate for the long span, and the quantity of reinforcement bar and concrete is raised. Recently, the post-tensioning system has been introduced and used widely as an alternative method. Nevertheless, in Korea, it is not used broadly due to lack of the understanding and field experience. Especially, the post-tensioning system is hesitated to use due to uncertainty of construction ability and economics. This paper will introduce applicability to site and economics of unbonded post-tensioning system through construction examples.

• Computers and Concrete
• /
• v.16 no.3
• /
• pp.381-397
• /
• 2015

Connections are the most important regions in a structural system especially for buildings in seismic zones. In R.C. structures due to large dimensions of members and lack of cognition of the stress distribution in a connection, reaching a comprehensive understanding of the connection behaviors becomes more complicated. The shear wall-to-floor slab connections in lateral load resisting systems have a potential weakness in transferring loads from slabs to shear walls which might change the path of load transformation to shear walls. This paper tries to investigate the effects of seismic load combinations on the behavior of slabs at their connection zones with the shear walls. These connection zones naturally are the most critical regions of the slabs in RC buildings. The investigation carried on in a simulated environment by considering three different structures with different shear wall layout. The final results of our study reveal that layout of shear walls in a building significantly affects the magnification of forces developed at the shear wall-floor slab connections.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.23 no.12
• /
• pp.836-842
• /
• 2011

It has been shown that the air-conditioning system with slab cooling storage is effective in cutting peak load and utilizing nighttime electric power. The stochastic properties of internal heat generation which has great influence on the cooling load are examined in this paper. Based on the measured cooling load and electric power consumption in an office building with slab cooling storage, stochastic time series models to simulate these random processes are investigated. Furthermore, a calculated result by an optimal control method of thermal analysis taking into account the internal heat is compared with the measured cooling load.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.11a
• /
• pp.65-68
• /
• 2004

In the seismical capacity evaluation for RC structure wall-slab joint is very important factor. Because lateral load is resistance element and gravity load resistance element are acted mutually in the wall-slab joint. In this paper, to improve the seismic capacity of the wall-slab joint in the existing wall type apartments experiment which improve and retrofit a seismic capacity by unequal angle bracing and carbon sheet attachment are carried out. These methods are also economic and simple in mitigating seismic hazard, improve earthquake-resistance performance, and reduce risk level of building occupants. From the experimental results, the change of strength, degration of stiffness, and energy dissipation are evaluated. It can be concluded that these methods are effective in improving the seismic performance.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.05a
• /
• pp.171-172
• /
• 2011

Formwork accounts for a large proportion of the framework in high-rise construction projects in terms of the duration and cost. Especially, slab formwork has a significant influence on these factors. However, the current selection of formwork method in general contractors depends on the decisions of few experienced engineers, and layout planning of the formwork in specialty contractors requires lots of time by different floor types. As a preliminary study for developing an optimum layout model in slab formwork of high-rise building construction, this study proposes the process of the optimum layout model and determines a fitness function for use of the genetic algorithm aimed at table formwork.

• Advances in concrete construction
• /
• v.5 no.1
• /
• pp.49-63
• /
• 2017

Traditional reinforced concrete slabs and beams are widely used for building. The use of flat slab structures gives advantages over traditional reinforced concrete building in terms of design flexibility, easier formwork and use of space and shorter building time. Deflection of the slab plays a critical role on the design and service life of building components; however, there is no recent research to explore actual deformation of concrete slab despite various advancements within the design codes and construction technology. This experimental study adopts the Hydrostatic Levelling Cells method for monitoring the deformation of a multi-storey building with flat slabs. In addition, this research presents and discusses the experimental results for the vertical deformation.