• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.421-426
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• 1999

The purpose of this study is to investigate the durability design method of reinforced concrete structure in order to establish a rationally combined design system of structural and durability design, that is to say performance-based design. In literature study, the integrated design of concrete structure studied JCI committe is very intensive durability design method for reinforced concrete structure. Specially, B root durability design method for selection of verification level is very effective method in the view of modeling of materials and structural properties to analyze safety and serviceability of RC structures.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.821-826
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• 2001

This paper presents four types of strut-tie model design approaches of structural concrete through the anchorage zone design of a post-tensioned concrete I-beam. The differences and distinctive feature of each approach in terms of structural type of selected strut-tie model, external force acting on strut-tie model, effective strength of concrete strut, and strut-tie model design procedure are analyzed and compared. The outcomes of present study enable structural designers to understand the merits and demerits of each strut-tie model design approach, and thus to conduct reasonable and accurate design of structural concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.241-246
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• 2000

In the strut-tie model design of structural concrete, the importance of the effective strength of concrete strut has been overlooked by many practitioners. The authors believe that the effective strength of concrete strut is an important factor not only in determining steel tie forces but also in verifying the nodal zone strength and geometric compatibility condition of a selected strut-tie model. This study evaluate the effect of the effective strength of concrete strut on structural concrete design by applying the different effective strut strengths to the strut-tie model design of a post-tensioned anchorage zone and a continuous concrete deep beam.

• Computers and Concrete
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• v.6 no.6
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• pp.491-503
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• 2009

This paper presents a design framework developed using axiomatic design (AD) theory that can be applied in the design process of porous concrete. The main contribution of this paper is the definition of an AD framework based on the needs and functional requirements of porous concrete. The framework shows how AD theory can be used to provide guidelines for proportioning and manufacturing porous concrete. The advantage of the AD approach is that it systemizes the way to decouple design parameters and makes designers to think rationally between what we want to achieve and how we propose to satisfy the functional requirements of porous concrete. In this paper, test results of laboratory-size porous concrete specimens under compression were analyzed to evaluate the performance of the porous concrete based on the desired functional requirements.

• Structural Engineering and Mechanics
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• v.71 no.6
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• pp.643-656
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• 2019

A new seismic design methodology was proposed for precast concrete diaphragms. This methodology adopts seismic design factors applied on top of current diaphragm design forces. These factors are aimed to produce diaphragm design strengths aligned with different seismic performance targets. These factors were established through extensive parametric studies. These studies used a simple evaluation structure with a single-bay rectangular diaphragm. The simple evaluation structure is suitable for establishment of the design factors over comprehensive structural geometry and design parameters. However, the application of the design factors to prototype structures with realistic layouts requires further verification and investigation. This paper presents diaphragm design of several precast concrete parking structures using the new design methodology and verification of the design factor through nonlinear dynamic time history analyses. The seismic behavior and performance of the diaphragm were investigated for the precast concrete parking structures. It was found that the design factor established for the new design methodology is applicable to the realistic precast concrete parking structures.

• Computers and Concrete
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• v.6 no.2
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• pp.95-108
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• 2009

In the current research, a displacement-based seismic design scheme to retrofit reinforced concrete columns using FRP composite materials has been proposed. An accurate prediction for the nonlinear flexural analysis of FRP jacketed concrete members has been presented under multiaxial constitutive laws of concrete and composite materials. Through modification of the displacement coefficient method (DCM) and the direct displacement-based design method (DDM) of reinforced concrete structures, two algorithms for a performance-based seismic retrofit design of reinforced concrete columns with a FRP jacket have been newly introduced. From applications to retrofit design it is known that two methods are easy to apply in retrofit design and the DCM procedure underestimates the target displacement to compare with the DDM procedure.

• Proceedings of the Korean Institute of Building Construction Conference
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• v.y2004m10
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• pp.11-14
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• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.611-616
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• 2013

Nowadays concrete pavement is increasing, since it is more durable than asphalt pavement. And the concrete pavement with lateral rain groove may induce high level of concrete whine noise as pure tone. In this paper, the design factor for good concrete whine noise is considered in view of tire pattern and structure design. In respect of tire pattern design, the tire having a cap tread with high center part stiffness and low shoulder part stiffness shows best concrete whine noise performance. And in respect of tire structural design, the tire with a thick center part of cap tread and low tread part stiffness show best concrete whine noise performance.

• Korean Journal of Construction Engineering and Management
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• v.20 no.1
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• pp.133-140
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• 2019

The concrete mix should be designed and produced to reflect the specific site conditions during concrete placement. That is, the concrete mix design should be planned considering temperatures, work environments, pouring methods, etc. The objective of this research is to understand the external factors of curing temperature and delay time that influence concrete strengths during pouring work, and provide concrete mix design that can be most robust to the effects of external factors. The Taguchi's robust method is used in preparing the concrete mix design to achieve the research objective. In a case study, an indoor concrete test was performed to find the optimal combination of concrete mixes with external factors of curing temperature and delay time. Concrete test cylinders were made to test concrete strengths given different external factors. The study results showed that the optimal performance of concrete strength can be achieved by applying the robust method when preparing a concrete mix design.

• Journal of Radiation Protection and Research
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• v.32 no.4
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• pp.190-193
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• 2007

The objective of this study is to recommend the radiation protection design parameters from the shielding point of view for concrete wall between the decay tank room and the primary pump room in TRIGA Mark-II Research Reactor Facility. The shield design for this concrete wall has been performed with the help of Point-kernel Shielding Code Micro-Shield 5.05 and this design was also validated based on the measured dose rate values with Radiation Survey Meter (G-M Counter) considering the ICRP-60 (1990) recommendations for occupational dose rate limit ($10{\mu}Sv/hr$). The recommended shield design parameters are: (i) thickness of 114.3 cm Ilmenite-Magnetite Concrete (IMC) or 129.54 cm Ordinary Reinforced Concrete (ORC) for concrete wall A (ii) thickness of 66.04 cm Ilmenite-Magnetite Concrete (IMC) or 78.74 cm Ordinary Reinforced Concrete (ORC) for concrete wall B and (iii) door thickness of 3.175 cm Mild Steel (MS) on the entrance of decay tank room. In shielding efficiency analysis, the use of I-M concrete in the design of this concrete wall shows that it reduced the dose rate by a factor of at least 3.52 times approximately compared to ordinary reinforced concrete.