• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.69-70
• /
• 2012

This paper is to investigate the engineering properties of the concrete incorporating different types of low heat generating binders subjected to various W/B. As expected, it is found that increase of W/B resulted in a decrease of hydration heat and compressive strength. It also showed that the application of high early strength and low carbon type mixture had favorable strength development at early and later age, while hydration heat showed rather higher than existing low heat mixture.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.10a
• /
• pp.341-344
• /
• 1999

In the case of the offshore concrete structures like the anchorage block of a suspension bridge of Kwangan Grand Road, there is a need of the concrete which has low heat of hydration and good resistance for sea-water attack. In this study, the blended super low heat cement which satisfies that requirement was developed and several tests were carried out. The concrete using the blended super low heat cement showed lower adiabatic temperature rise than 3$0^{\circ}C$ and good early strength. Also, its passed charge(coulomb) to resist chloride ion penetration was very low.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.195-196
• /
• 2012

In this study, it was investigated early age strength generation of low cement concrete with type and addition ratio of hydration accelerator obtaining fundamental data for the application in construction field.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2015.11a
• /
• pp.19-20
• /
• 2015

In this research, by examining the influence that high quality fine aggregate and low quality fine aggregate have on the strength of concrete through tests, the manifest strength of concrete according to high quality fine aggregate was reviewed. The results showed that compared to low quality fine aggregate usage mixture, the unit volume to achieve the same liquidity decreased and accordingly the W/B also decreased therefore increasing the strength of concrete, and as high quality fine aggregate was used, it is determined that there can be improvements to the economically feasibility of usage mixture and improvement in durability etc.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.55 no.3
• /
• pp.123-128
• /
• 2013

This study was performed to evaluate the slump flow, air content, setting time, compressive strength, adiabatic temperature rise and diffusion coefficient of chloride used ordinary portland cement, crushed coarse aggregate, crushed sand, river sand, fly ash, limestone powder, blast furnace slag powder and superplasticizer to find optimum mix design of low carbon green concrete for structures. The performances of low carbon green concrete used fly ash, limestone powder and blast furnace slag powder were remarkably improved. This fact is expected to have economical effects in the manufacture of low carbon green concrete for structures. Accordingly, the fly ash, limestone powder and blast furnace slag powder can be used for low carbon green concrete material.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05b
• /
• pp.549-552
• /
• 2006

Generally the ultra-high strength steel reinforced concrete has rich mix composition composed of high-strength type mineral admixtures and as a result of very low water-binder ratio(about under w/b=25%), it reveals ultra-high compressive strength(about over 100Mpa). Also, in order to obtain sufficient toughness after construction, we usually mix a large quantity steel fiber with ultra-high strength steel reinforced concrete therefore we must use proper mixer for workability. When we make the ultra-high strength steel reinforced concrete we need more long mixing time or much super-plasticizer than when we manufacture normal concrete. These bring about economical problems and performance deterioration. Therefore, in this study, in order to manufacture easily ultra-high strength steel reinforced concrete we develope a dedicated mixer for ultra-high strength steel reinforced concrete with high speed type. It carried out the examination for comparison between the dedicated and general type mixer, the analysis and counterplan of the point at issue when we manufacture ultra-high strength steel reinforced concrete by the dedicated mixer.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.04a
• /
• pp.166-171
• /
• 1999

Porous concrete contains about 20% voids after compaction so that it has high permeability which secures underground water resources. It is introduced in domestic since 1980' but has problems such as lack of optimized mixture, low strength and durability, efflorescence and other defects, etc. In this study, several mixture were designed based upon site works, and test specimens for compressive strength, tensile strength, flexual strength and permeability, were prepared in a laboratory. After 28days of curing, every performance was tested to find optimum mixture. The mixture was proposed as 380kg/㎥ of unit cement weight, 32% of W/C 10∼13mm of aggregate.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.11a
• /
• pp.553-556
• /
• 2003

This study is analyzed about the factor of adhesive strength characteristics, curing time, asphalt application, test temperature which are liquid waterproofing membrane of rubber-asphalt and chloroprene-rubber type for concrete bridge deck. According to the results, curing time is shorter, adhesive strength is less in chloroprene-rubber type. And also chloroprene-rubber and rubber-asphalt type are showed high adhesive strength in low temperature.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1992.04a
• /
• pp.131-136
• /
• 1992

Eight singly reinforced high strength concrete beams without web reinforcement were tested to investigate their behavior and to determine their ultimate shear capacities. In this study, the main variable was the ration of longitudinal reinforcement. Test results were compared with strength predicted by using ACI code, Zsutty's dquation and Bazant & Kim's equation. As the result, for the beams of low steel ratio, the margin of safety in ACI code may be disappeared. It was shown that Zsutty.s equation well predict the trend of the test data.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2001.11a
• /
• pp.1219-1224
• /
• 2001

In this study, concrete what plenty of fly ash used as binder is left in three condition humid condition($35^{\circ}C$), normal condition($20^{\circ}C$) and cold condition($5^{\circ}C$). Fly ash concrete is tested in fresh properties and early strength. The result of tests could give the decisive factor of form side's stripping time. The purpose of this study is presenting the stripping time data to help the construction work. The result of this study is below. 1. The plain concrete specimen in humid condition developed high strength before 5 days, then strength development is declined. 10 day strength of plain specimen is smaller than the normal condition specimen's. 2. The strength of the concrete which plenty of fly ash used is more developed than the concrete in normal condition. It says that fly ash concrete is useful in the humid condition. 3. As fly ash substitution rate is downsizing and outdoor temperature degree is low, form stripping times is getting shorter.