• Applied Chemistry for Engineering
• /
• v.24 no.4
• /
• pp.337-343
• /
• 2013

Membrane reactors have been showing a promising future and attracted increasing attention in the scientific community as they possess advantages in terms of enhanced catalytic activity and selectivity, combination of processes (reaction and separation), simplicity in process design, and safety in operation. In particular, solid electrolyte membrane reactor principles are realized in fuel cells, electrolyzers and reactors for hydrogenation of carbon dioxide and other economically viable reactions. In this review, as a young generation of ion conducting materials, high temperature proton conductors are discussed in terms of the current status of material development and their various applications.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.949-952
• /
• 2008

The latex modified concrete(LMC) was adds latex in the plain concrete as the latex has increase the durability of concrete. But it is added in LMC manufacture, which is a high price compares with different material and there is a weak point where the construction expense is very high. So, this study are decided mix proportion from the scope where the security strong point of LMC is possible and reduced the material expense by control the latex contents. and these mix proportions are estimated the chloride ion diffusion. The results of study appear that it can reduced the latex content until the $5{\sim}10$% of cements, and these mixtures are very low chloride ion diffusion.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.9 no.1
• /
• pp.181-188
• /
• 2005

Generally, high performance concrete has characteristics such as low water-cementitous material ratio, lots of unit binder powder, thus the drying shrinkage and autogenous shrinkage are tend to be increased. The purpose of this study is to investigate the effect of the glyclos based shrinkage reducing agent on the drying shrinkage and autogenous shrinkage of high performance concrete with 30% of water-cemetitious material ratio as a study to develop the technology to reduce the concrete shrinkage. Test results show that the drying and autogenous shrinkage of high performance concrete are reduced by about 20~35% at the mixing ratio of shrinkage reducing agent of 0.5%, and 1.0%, compared with plain concrete. Therefore, it analyze that the using of shrinkage reducing agent is effective to reduce the drying shrinkage and autogenous shrinkage of high performance concrete.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2015.11a
• /
• pp.132-133
• /
• 2015

In this research by examining the influence that low quality aggregate has on the strength of concrete through testing, the lowering of strength according to use of low quality coarse aggregate was reviewed. The results showed that when using low quality coarse aggregate, due to the quality of aggregate a high volume of units was required, and this caused the compression strength to be lowered. In conclusion it was confirmed that if the low quality aggregate was used as is without mix correction this would lead to faulty construction and if the aggregate was corrected to about 60 kg/m3 mix correction, this would lead to an economically infeasible concrete mix.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2015.11a
• /
• pp.17-18
• /
• 2015

In the case of concrete recently manufactured with a concrete mixing truck, although aggregate and cement are used as the main ingredients, from a costs savings perspective, low quality aggregates are processed and used as concrete aggregate. In the case of these low quality aggregates, the unit volume and unit binder weights are increased for manufacturing, and due to this problems such as dry shrinking of the architecture and economic infeasibility have arisen. Therefore by changing the aggregate material and the unit binder weights that are currently being distributed, this research analyzes the influence on concrete.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1998.10a
• /
• pp.307-312
• /
• 1998

Recently the study on high flowing concrete which has high workability and Self-compacting is being proceeded actively in the university and corporative laboratory. There are some cases that has been applied to the field. This high flowing concrete has higher fluidity and segregation resistance than Plain of flowing concrete. And it is being focused as a remarkable know-how which can make high-quality concrete and reduction effect of labor force. This properties of high flowing concrete are influenced by the relationship of several factors; binder content, water binder ratio and unit water content. It is the aim of this study to propose reference data at mix design of high flowing concrete, after comparing and analyzing the fluidity and strength properties of high flowing concrete according to water binder content ratio and unit water content.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1993.10a
• /
• pp.29-34
• /
• 1993

Although bonding material content of the high strength flowing concrete is very important in engineering properties, in rich mix concrete increasing the bonding material content may not follow more good properties. This study is to investigate the influence of the bonding material content affecting on the engineering properties of high strength flowing concrete, and this paper is to analyze the properties of fresh concrete. The results reveal that concrete of less bonding material content has about the same good consistency as concrete of more bonding material content, and that the evaluation methods of workability have to change in high strength flowing concrete.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1993.10a
• /
• pp.35-38
• /
• 1993

Although bonding material content of the high strength flowing concrete is very important in engineering properties, in rich mix concrete increasing the bonding material content may not follow more good properties. This study is to investigate the influence of the bonding material content affecting on the engineering properties of high strength flowing concrete, and this paper is to analyze the properties of hardened concrete. The results reveal that the strength of concrete having loss bonding material content is higher than that of concrete having more bonding material content, and that in proportion to increasing of concrete strength brittleness factors decrease, and that the static modulus of elasticity in this study is less than that in specification.

• Journal of the Korea Concrete Institute
• /
• v.14 no.2
• /
• pp.249-256
• /
• 2002

High performance concrete is prone to large autogenous shrinkage due to its low water to binder ratio (W/B). The autogenous shrinkage of concrete is caused by self-desiccation as a result of water consumption by the hydration of cement. In this study, the autogenous shrinkage of high performance concrete with and without fly ash was Investigated. The properties of fresh concrete, slump loss, air content, and flowability as well as the mechanical properties, compressive strength and modulus of elasticity, were also measured. Test results was shown that the autogenous shrinkage of concrete increased as the W/B decreased. For the same W/B, the autogenous shrinkage of high strength concrete with fly ash was considerably reduced although the development of its compressive strength was delayed at early ages. Furthermore, the autogenous shrinkage and compressive strength of high strength concrete were more rapidly developed than those of normal strength concrete. It was concluded that fly ash could improve the quality of high strength concrete with respect to the workability and autogenous shrinkage.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.1101-1104
• /
• 2008

Recently, active researches are conducted on high performance concrete(HPC) exhibiting high strength and high fluidity. These researches are resulting in increased applications on real structures. In order to satisfy the required performances, HPC makes use of large quantities of binder and presents low water-cementitious material ratio. Such mixing is increasing significantly the autogenous shrinkage, which subsequently is likely to favor the potential development of cracks. Therefore, we investigated the effect of used materials and mix proportions on the shrinkage properties of HPC, and of the use of expansive additives and shrinkage reducing agents on the HPC. The autogenous shrinkage of HPC using blast furnace slag are tend to be increased, in some case have the potential development of cracks by only the autogenous shrinkage. Also the using method in combination with expansive additive and shrinkage reducing agent is more effective than the separately using method of that.