• Korean Journal of Construction Engineering and Management
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• v.13 no.2
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• pp.48-57
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• 2012

A variety of studies on concrete have been performed to examine the advantages for structural material, but less attention has been paid to the contribution of concrete to finishing. Due to this matter, specific management guidelines for construction and quality on exposed concrete have not been clearly established despite more construction cost and quality control are required. This study analyzed a impact factors on the quality by survey of the existing research and practice. Field tests were performed using mock-up models to analyze the quality of exposed concrete according to form manufacture method, concrete mix proportion, and concrete placing method. Results indicate that the quality of exposed concrete was determined by concrete mix proportion and construction managements. Guidelines of quality control on exposed concrete in construction stages were proposed.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.705-710
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• 2002

Recently, there has been for a number of reasons growing interest in the use of porous concrete, and it is used as an ecological material. But, because the valuation methods of the quality on the fresh porous concrete aren't established up till now, it is difficult that the harden porous concrete is made sure of its required quality. This study is to present the measurement method of the void ratio on the fresh porous concrete and to analyze the influence of water-cement ratio and vibrating time on the binder content covered a coarse aggregate. Results of this study were shown as follows; The measurement methods of the void ratio and aggregate-binder weight ratio on the fresh porous concrete can be useful as data for the quality control of fresh porous concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.327-328
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• 2021

In the manufacturing process of ready-mixed concrete, quantity management directly affects the workability and strength of concrete. Therefore, water quantity is the most important management factor for water quality control of ready-mixed concrete. It can be said that the number of unit water in the mix design, the water quantity due to the surface water contained in the aggregate used, and the water quantity taking into account the concentration of sludge contained in the recycling water when using the recycling water are factors that affect the quantity management of ready-mixed concrete. In this study, as a stable quality control method of ready-mixed concrete, a quantity management method by aggregate surface water and a sludge concentration management method according to the use of recycling water were proposed. Thus, we tried to suggest an efficient quantity management method for stabilizing the quality of ready-mixed concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.614-617
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• 2006

This study investigates the quality control and the finishability improvement properties of durable marine concrete under construct in Geo-je Ka-duk fixed link project. Below $3.5\times10^{-12}m^2/s$ chloride migration coefficient and above 40MPa compressive strength are required for the caisson structure concrete. The quality control was performed from physical-chemical analysis of raw materials to concrete test. Also, the efficiency of vibration type and action interval were tested to remove the entrapped air on the faced to form. And kinds of form and remolding agent were also tested. This paper aim to enhance the practical use of high performance concrete to construction field.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.983-986
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• 2007

Concrete surface grinding is required for flatness and adhesiveness of concrete surface. The procedure is, however, labor intensive and has a hazardous work condition. Also, the productivity and the quality of concrete surface grinding depend on the levels of worker. Thus, the development of remote controlled concrete surface grinding equipment is necessary to prevent the environmental pollution and to protect the workers from hazardous work condition. However, it is difficult to evaluate the grinded surface objectively in a remote controlled system. The machine vision system developed in this study takes the images of grinded surface with the network camera for image processing. Then, by representing the quality test results to the graphic MMI program of the remote control station, the quality control system is constructed. The machine vision algorithm means the image processing algorithm of grinded concrete surface and this paper presents the objective quality control standard of grinded concrete surface through the application of the suggested algorithm.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.102-107
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• 2005

All concrete structure in agricultural improvement project must satisfied durability, serviceability, safety. It is important for structure that satisfied these natures to good quality at design and construction step, and must continuous maintenance. Most of the concrete structures is construct at winter season, is contacted with water, has various type and sporadic in wide area. The objective of this study is to make the Concrete-Quality-Control diagram for agricultural infrastructure project using GIS. And, analyze the diagram with external factor(terrain, stream, economic etc.) to know the factor of concrete quality control.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.223-228
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• 2000

Although construction company try to get good quality control it's enough to study about developing objective evaluation method and checking quality method. It is important to meaning concrete quality at placing point, immediate quality checking method is limited. The purpose of this study is to develop new method to know early 28-day concrete for getting faithful quality control. The results of this study are as follows :1) With sealed molds, reduced moisture volatilization to more than 50% and enlarged 20% accelerated compressive strength than before one. 2) Accelerated compressive strength of concrete specimen shows higher strength when it was in the air for long time 3)Interrelation with 7-day and 28-day strength were 0.781,0.90, It is higher than before one

• Proceedings of the Korea Concrete Institute Conference
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• 1994.04a
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• pp.260-265
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• 1994

High strength concrete(65MPa) was used for construction of the bulk cement storage silo by using sliding form. This paper presents mix design, production, quality control and experience with field application of high strength concrete under cold weather conditions. It is shown to be possible to produce high strength concrete of compressive strength of 50~60 MPa by using high-range water reducer to lower w/c ratio with appropriate quality control.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.373-376
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• 2008

The objective of this study is to investigate the properties of fresh concrete with recycled fine aggregates. Three different kinds of fine aggregate with natural, high and low quality recycled aggregates were prepared. The concrete mixtures were produced with test parameters of replacement ratio of recycled fine aggregate. The properties of the fresh concrete were measured by means of slump and air content according to elapsed time. Quality control method to maintain the constant total mixing water for recycled aggregate concrete was suggested. The all concrete mixtures were produced with approximately the same slump on the job site after an hour. Test results indicated that compressive strength of the concrete mixtures with constant slump is not affected by the replacement ratio of recycled fine aggregate. Therefore, the practical way for the quality control of recycled aggregate concrete is to maintain the constant total mixing water.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.285-291
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• 1997

This study is the experimental results on the applicability of the super flowing concrete, which is the pre-cast concrete, to various cases. The primary purpose of this study is to verify the demolding strength, the handling strength of the super flowing concrete at various curing conditions, and the site quality control of the DWS (Daewoo Multi-Room Modular Construction System). From the experimental works, required strength and curing cycles are satisfied. Furthermore site quality control details and quality of the pre-cast concrete using the super flowing concrete are obtained. From now on, this study may suggest how to apply the super flowing concrete for common circumstance.