• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.1-5
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• 2005

There are a lot of problem about waterproofing membrane coating for concrete deck of bridge and waterproofing sheets for concrete of deck of bridge because it couldn't confirm waterproofing's defeat after construction. These problems make a waterproofing material damage and concrete deck of bridge damage. So It needs a lot of money for repair work and reinforcement work. Therefor the structure slab of using waterproofing material protect invasion of water. Also, Concrete deck of bridge need a endurance permeability for the reduction repair payment. In this study, An experimental study on the quality standardization test method waterproofing layer on working of live load

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.521-526
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• 1997

The Spin Tester(High Speed Balancing and Overspeed Test Facility), which is designed for the quality control of turbine, generator, and rotors was supposed to be constructed with the use of Steel Fiber Reinforced Concrete(SERC) for reducing the risk of accident while operation. However, it was very existence of fiber concrete due to there are two major concern in the SFRC work: one is existence of fiber ball due to inhomogeneous mixing, the other is the segregation of the concrete materials. To avoid these possible problems, the S/a was controlled about 55% to reduce the segregation and the high range AE water reducing agent was used to maintain the slump over the value of 18cm. With these careful consideratons, the SFRC work was done successfully by only using regular equipments like pump car and vibrator.

• KCI Concrete Journal
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• v.11 no.3
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• pp.141-151
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• 1999

In the replacement of bearing system of bridges, the jacking work to secure work spaces may cause damage of the superstructure, hence the behavior of superstructure by the jacking force must be considered. Especially, in prestressed concrete I-type girder bridges, considering the stress concentration at the girder and the load redistribution of superstructure, the allowable jacking force and jacking sequence have to be determined. In this study, an analytical method is proposed to calculate the jacking force and overall jacking sequence for the replacement of bearing system without any damage to the superstructure. The stress concentration at the girder and load redistribution of the deck due to jacking force are considered to compute the allowable jacking force for each girder and overall jacking sequence for girders in the deck. Using the solution algorithm developed in this study, the optimum jacking sequence and required jacking force for the prestressed concrete I-type gilder bridge having the standard sections are calculated.

• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.412-418
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• 2010

This paper presents the results of experimental work on both mechanical properties and durability of concrete or mortar incorporating silica fume. The aim of this study was to investigate the effect of replacement of silica fume on the performance of hardened concrete or mortar. The replacement levels of silica fume that replaced cement in this work were 0%, 5%, 10% and 15%, respectively. The results of this study indicate that both mechanical properties and durability of concrete are greatly dependent on the replacement levels of silica fume. As the replacement level of silica fume increased, the mechanical properties including compressive and flexural strengths, and static modulus of elasticity were proportionally enhanced. Furthermore, it was found that silica fume had some beneficial effects on the resistances to both chloride ions penetration and sodium sulfate attack. However, it exhibited poor resistances to both freezing-thawing action and magnesium sulfate attack.

• Magazine of the Korea Concrete Institute
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• v.6 no.6
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• pp.66-75
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• 1994

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.157-160
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• 2003

In order to reduce the construction cost and period without degrading the quality, construction companies are making a lot of efforts to prefabricate and mechanize the construction process, and introducing and utilizing various techniques of construction time management in the process of construction. However, due to the various factors (such as weather conditions, labor factors, supply of equipment and materials, safety accident, etc) in the process of construction, construction projects are not frequently completed within the scheduled Period. This research is to examine the current status of construction time management and factors causing delay in construction with regard to the concrete work (such as form work, steel reinforcement, and concrete work) in building apartments.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.861-868
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• 1999

Drainage concrete pavement, unlike water permeable concrete pavement, is to preclude the pavement from overflowing with water, such as rain water, from infiltrating into earth by placing a border in the middle layer which makes water to flow through the surface of the border to the conduit. Drainage concrete pavement enhances car wheel resistance to slippery and wet road surface and imbibes noise caused by friction on the road. Also, by using pigment, it adds to the beauty of the environment. Drainage concrete pavement can be used for sidewalks, roadways, parking lots and expressways.

• Journal of Industrial Technology
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• v.28 no.A
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• pp.125-132
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• 2008

As of 2003, construction waste has been produced at the level of 130,614.8 tons/day, in which the amount of waste concrete was 92,639.1 tons/day and accounted for about 66.4% of the amount of construction waste. Waste concrete is mainly produced in construction work and civil engineering work. Especially, road surface crushing method using a large amount of water requires thorough management of concrete wastewater. The aim of this study was to analyze water pollution due to concrete wastewater generated in repair of bridge deck using road surface crushing equipment and to suggest reasonable countermeasures for solve the problem. In this study, it was surveyed current conditions of produced concrete wastewater in bridge deck repair, analyzed physical features of concrete wastewater, expected effects of water pollution on inflow rivers if it is not treated, established treatment plan of water pollution by categories, and calculated capacity of each treatment process and required amount of necessary chemicals. As a result of sampling wastewater generated in field sites and testing it at a lab scale, it was revealed that the original wastewater was produced in removing concrete from bridge deck slabs using surface crushing equipment whose pH was 12.53, CODMn was 12.910mg/L, SS was 547.0mg/L, and other heavy metals were included in extremely small quantities.

• Advances in concrete construction
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• v.6 no.1
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• pp.87-102
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• 2018

Utilization of waste tires may be considered as one of the solution to the problems faced by the local authorities in disposing them. Reclaimed rubber (RR) is being used in concrete for replacing conventional aggregates. This research work is focused on the strength prediction of reclaimed rubber concrete using a Genetic Algorithm (GA) for M40 grade of concrete and comparing it with experimental results. 1000 sets were taken and 100 iterations were run during training of GA models. A base study has been carried out in this research work partially replacing cement with three types of fillers such as Plaster of Paris (POP), Fly Ash (FA) and Silica Fume (SF). A total of 243 cubes were cast and tested for compression using a Universal Testing Machine. It was found that SF produced maximum strength in concrete and was used in the main study with reclaimed rubber. Tests were conducted on 81 cube samples with a combination of optimum SF percent and various proportions of RR replacing coarse aggregates in concrete mix. Compressive strength tests of concrete at 7, 14 and 28 days reveal that the maximum strength is obtained at 12 percent replacement of cement and 9 percent replacement of coarse aggregates respectively. Moreover the GA results were found to be in line with the experimental results obtained.

• Computers and Concrete
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• v.25 no.5
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• pp.479-484
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• 2020

This work performed to analyses the impact of hooked end steel fibres on the mechanical properties of high performance concrete. The mechanical properties considered incorporate compressive strength, split tensile strength and flexural strength. Taking in to thought parameters, such as, volume fraction of fibres, fibre aspect ratio and grade of concrete, a logical strategy called Taguchi technique was utilized to discover the ideal blend of factors. L9 Orthogonal Array (OA) of Taguchi network comprising of three variables and three dimensions is utilized in this work. The evaluations of concrete considered were M60, M80 and M100. M60 contained 15% of metakaolin as bond swap though for M80 it was 5% of metakaolin and for M100 it was 10% metakaolin and 10% of silica smolder. The volume portion of fiber was fluctuated by 0.5%; 1% and 1.5% and the viewpoints proportions considered were 50, 60 and 80. The test outcomes demonstrate that incorporation of steel fibres enhance significantly the the strength characteristics of concrete, predominantly the splitting tensile strength and flexural strength. In light of relapse investigation of the test information scientific models were produced for compressive strength, split tensile strength and flexural strength of the steel fibre-reinforced high performance concrete.