• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.135-140
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• 2001

This study was developed high-quality a large size precast channel structure using polymer concrete to improve quality of the product as well as to enhance construction quality. Precast PC represent the fastest growing segment of the polymer concrete industry. The fast curing, high strength, and low impermeability permit thin section and rapid reuse of moulds. Developed precast channel structure will be structural experiment and analysis. Also, through an example to construct will be develop the most suitable section survey and make practicable.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.1
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• pp.159-169
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• 2002

This study is intended to discuss the application of expansive additives for concrete to improve the durability of precast concrete box culvert by inducing the chemical prestress. The precast concrete box culvert using expansive cement are tested to verify the effect of expansive additives. The results show that the initial cracking load and yielding load of the expansive cement numbers are increased when they are compared with those of the normal concrete. In the prototype precast concrete box culvert experiment, initial crack control effect and strength of joint are increased, but the deflection is decreased by expansive cement. Brides, reinforcement ratio is decreased about 14.6 percent in compering with the case of using normal cement. If can be the concluded that the use of expansive additives to induce the chemical prestress was improve the durability in concrete box culvert.

• Earthquakes and Structures
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• v.24 no.2
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• pp.141-153
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• 2023

The presented paper considers infill masonry walls' influence on the seismic reliability of precast concrete frames. The recent Bojnord earthquake on May 13th, 2017 in Iran (MW 5.4) illustrated that the infill masonry walls play a crucial role in the damage extent and life safety issues of inhabitants in the precast concrete buildings. The incremental dynamic analysis (IDA) approach was used to determine the fragility curves of the represented damaged precast frame. Then, by integrating site hazard and structural fragilities, the seismic reliability of the represented precast frame was evaluated in different damage limit states. Additionally, the static pushover analysis (SPA) approach was used to assess the seismic performance assessment of the precast frame. Bare and infilled frames were modeled as 2D frames employing the OpenSees software platform. The multi-strut macro-model method was employed for infill masonry simulation. Also, a relatively efficient and straightforward nonlinear model was used to simulate the nonlinear behavior of the precast beam-column joint. The outputs show that consideration of the masonry infilled wall effect in all spans of the structural frame leads to a decrease in the possibility of exceedance of specified damage limit states in the structures. In addition, variation of hazard curves for buildings with and without consideration of infilled walls leads to a decrease in the reliability of the building's frames with masonry infilled walls. Furthermore, the lack of infill walls in the first story significantly affects the precast concrete frame's seismic reliability and performance.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.113-118
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• 2007

In this study, we select a site adopting real composite precast concrete method. Estimating real construction cost and imaginary cost appling reinforced concrete method in the site, we compare the costs. Through using high intensity concrete and prestressed concrete, amount of concrete is reduced more than 50% but there isn't big gap in material cost. In the main construction cost of composite precast concrete method, the material cost with production cost and transportation cost are in that, joints and topping concrete are account for 90%. But in case of reinforced concrete, labor cost spent at concrete steel bar and form is account for 30%. In the cost of attached, compared with composite precast concrete method, the reinforced concrete method taken in big portion by temporary work and scaffolding is twice as much as composite precast concrete method in construction cost. Therefore, economic efficiency is excellent reducing 11% total cost of composite precast concrete method from the reinforced concrete method.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.10
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• pp.155-162
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• 2019

Hybrid precast concrete panel is a wall element that is able to quickly construct the core wall structure for moderate-rise modular buildings. Hybrid precast concrete panel has unique characteristics which is a pair of C-shaped steel beams combined at the top and bottom of a concrete wall, In this study, an improved anchorage detail for vertical rebar is proposed to ensure the lateral force resistance performance of hybrid precast concrete panel emulating monolithic concrete wall. Also, the structural performance of horizontal connection is investigated experimentally with the bolt spacing parameter. And the behavior of hybrid precast concrete panel with the improved detail is compared with the monolithic concrete wall tested in a previous study. Finally, the required thickness of C-shaped steel beam to eliminate or minimize the deformation in horizontal connection is calculated by prying action equation.

• Journal of the Korea Institute of Building Construction
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• v.5 no.1 s.15
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• pp.89-96
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• 2005

The increase of hish-rise residential-commercial buildings is required to cut down a term of works and the cost of construction. Reinforced concrete structures and steel framed reinforcement concrete that are commonly used have the difficulty in reducing them. Therefore, the purpose of this study is to propose a new precast concrete complex system and to analyze its economical feasibility. The economic analysis is performed through comparing the cost of a high-rise reinforced building that was already constructed with that of the new proposed precast concrete system, which is limited to structural frame work of typical floors. This study shows that the proposed precast concrete complex system is economical. Further research should be directed at including the influence of a term of works.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.459-460
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• 2009

The purpose of this study is to develop precast concrete structural wall panel that can assure reliable seismic performance. In the previous study, the connection of precast concrete structural wall has some problems in seismic performance. Therefore, this research proposed the precast concrete structural walls which can improve seismic performance. And their seismic performance was verified through lateral loading experiment.

• Computers and Concrete
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• v.16 no.4
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• pp.643-667
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• 2015

3-dimentional precast recycled aggregate concrete (RAC) finite element models were developed by means of the platform OpenSees to implement sophisticated nonlinear model subjected to seismic loads. Efforts were devoted to the dynamic responses (including dynamic characteristics, acceleration amplifications, displacements, story drifts) and capacity curve. In addition, this study extended the prediction on dynamic response of precast RAC model by parametric study of material properties that represent the replacement percentage of recycled coarse aggregate (RCA). Principles and assumptions that represent characteristics of precast structure and influence of the interface between head of column and cast-in-place (CIP) joint on the stiffness of the joints was put forward and validated by test results. The comparison between simulated and tested results of the precast RAC frame shows a good correlation with most of the relative errors about 25% in general. Therefore, the adopted assumptions and the platform OpenSees are a viable approach to simulate the dynamic response of precast frames made of RAC.

• Steel and Composite Structures
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• v.28 no.1
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• pp.39-49
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• 2018

The concrete bridge decks are usually precast and in-situ assembled with steel girders with post-pouring joint in the construction practice of super-wide steel-concrete composite beam. But the difference of concrete age between the precast slabs and the post-pouring joint has been not yet considered for the long-term performance analysis of this kind composite beam. A simply supported precast-assembled T-shaped beam was taken as an example to analyze the long-term performance of steel-concrete composite beam with post-pouring joint. Based on the deformation coordination conditions of the old-new concrete deck and steel girder, a theoretical model for the long-term behavior of precast-assembled composite beam is proposed in this paper according to age-adjusted effective modulus method. Then, the feasibility of the proposed model is verified by the available test data from the Gilbert's composite beams. Parametric studies were preformed to evaluate the influences of the cross-sectional area ratio of the post-pouring joint to the whole bridge deck, as well as the difference of concrete age between the precast slabs and the post-pouring joint, on the long-term performance of the composite beam. The results indicate that the traditional method without considering the age difference would seriously underestimate the effect of creep and shrinkage of concrete bridge decks. The concrete age difference between the precast slabs and the post-pouring joint should be demonstrated for the life cycle design and long-term performance analysis of precast-assembled steel-concrete composite beams.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4A
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• pp.407-419
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• 2009

The purpose of this study is to investigate the seismic behavior of precast segmental PSC bridge columns with precast concrete footings and to provide the details and reference data. Six precast segmental PSC bridge columns were tested under a constant axial load and a cyclically reversed horizontal load. A computer program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. A bonded or unbonded tendon element based on the finite element method, that can represent the interaction between tendon and concrete of prestressed concrete member, is used. A joint element is modified to predict the inelastic behaviors of segmental joints. This study documents the testing of precast segmental PSC bridge columns with precast concrete footings and presents conclusions based on the experimental and analytical findings.