• Proceedings of the Korea Concrete Institute Conference
• /
• 1998.10a
• /
• pp.313-318
• /
• 1998

Generally, the concrete constructed during cold weather has the frozen damage which cause the fatal damage so that heat curing and sheet curing was performed to prevent the early freezing of concrete. However, partial refrigeration caused by thermal gradient has many troubles so that the construction hasn`t been done as possible. This paper presents the development of strenth properties and optimal mix design against frozen damage under the cold weather, 1$0^{\circ}C$ below the zero.

• Journal of Industrial Technology
• /
• v.16
• /
• pp.25-30
• /
• 1996

The waste foundry sand might be recycled in concrete, resulting in energy saving and environmental protection. An half Factorial Experiments were performed with the variables of W/C ratio, S/A, Sand/Waste foundry sand ratio and Slump as a preliminary study for optimum mix design of concrete. The results show that then W/C ratio is the most important factor to the concrete strength. The substitute of waste foundry sand up to 30% has little influence, saying that it can substitute the fine aggregate without damaging the concrete properties.

• Journal of Industrial Technology
• /
• v.16
• /
• pp.39-44
• /
• 1996

The waste basalt might be recycled in concrete, resulting in energy saving and environmental protection. An half Factorial Experiments were performed with the variables of W/C ratio, S/A, Crushed stone/Basalt ratio and Slump as a preliminary study for optimum mix design of concrete. The results show that the W/C ratio is the most important factor to the concrete strength. The substitute of waste basalt up to 100% has little influence, saying that it can substitute the coarse aggregate without damaging the concrete properties.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2016.10a
• /
• pp.85-86
• /
• 2016

Recently damages caused by the additional costs and degradation in durability combined deterioration due to plain concrete deterioration has occurred. In particular, in the case of the finish that is not exposed to the outside air in the concrete to respond to the harsh environment (freeze-thawing, calcium laying, etc.), to establish a quality control way for the process and the concrete mix design for it.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2002.10a
• /
• pp.549-554
• /
• 2002

In Powder System, SCC demands high dosage of superplasticizer and a lage amout of powder for suitable fluidity and viscosity. Okamura's method of most representative mixing design method in SCC of Powder-System is unfavorable economically because of using a large amount of powder. In addition, many ready-mixed concrete plants do not use his mix design method and procedure due to complexity for practical application. Therefore, Nan Su proposed more simple mix design method than Okamura's. It had an advantage in simplicity in practical application and required a smaller amount of powders compared with Okamura's method. This paper proposed an optimal mixture proportion of SCC with consideration of Nan Su's method. The new and modified mix design method required a smaller amount of powder than that of Nan Su's. To check the properties of SCC, considered with the requirements specified by the Japanese Society of Civil Engineering.(JSCE)

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2001.11a
• /
• pp.40-45
• /
• 2001

The purposes of this study were mix design and quality control of high strength concrete for the construction of high rise complex structure. Desired performances of this high strength concrete were slump flow 50$\pm$10cm, air content 4.5$\pm$1.5% and design strength 400kgf/$cm^2$. Experimental flow was that optimal mix design was selected in the indoor experiment and after that, producing test was done in the batcher plant. Excel lent results of experiment was obtained from binder content 475kg/$m^2$ with replacement ratio 10% of fly ash. The results of field application of high strength concrete was sufficiently satisfied both flowability and compressive strength.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.04a
• /
• pp.874-879
• /
• 2000

A prototype expert system for normal concrete mix design was developed using an technical consulting system development tool, EXSYS Professional. The knowledge contained in the system was obtained from the standard specifications of Korea Concrete Institute, American Concrete Institute and from the related British Standards. The knowledge base and user interface will be expanded to cover wider scopes of the problems. If the system is successfully developed as an operational system, it will produce a great deal of economic benefits by reducing the time and money needed to obtain an expert's judgement and experience in decision making for repetitive tasks related to concrete mix proportions.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.04a
• /
• pp.189-194
• /
• 2000

The optimum mix proportioning of concrete is to produce a concrete which satisfies the strength, workability and durability required with minimum component of materials. However in practice the cement content of mix proportioning in construction field is normally higher then required. In this study, the existing mix proportioning of concrete currently used in Korea Highway Corporation has been reviewed by reducing 10kg of cement content by 3~5 strength in strength and workability during the first year of this project. The optimum mix design is established based on the results of the above review and durability were examined during the second year. The experimental results though 2 year show that 103~0% of the reduction of cement content still satisfies the specified strength of concrete and produces higher durability concrete.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.06a
• /
• pp.94-95
• /
• 2020

This paper introduces the mix design and performance evaluation of Ultra-High Performance Concrete (UHPC). The concrete mixture is designed to achieve a densely compacted cementitious matrix via the modified Andreasen & Andersen particle packing model. The compressive strengths of UHPC designed by this method reached 154MPa. The relationship between packing theory and compressive strength of UHPC is discussed in this paper.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2009.05a
• /
• pp.231-232
• /
• 2009

In this study, the properties of early strength development for high performance concrete according to mix design were examined In particulara, we examined the mineral addmixture influence for mix design.