• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.58-59
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• 2020

The change of temperature and humidity in early-age concrete has a great influence on the durability of the structure. In this study, a reliable wireless sensor network system and a concrete embedded type Compressive strength prediction sensor were designed using the Arduino platform. The accuracy of the compressive strength prediction sensor was verified through a mock-up experiment, and it was confirmed that the experiment had sufficient accuracy to be used in the field environment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.45-46
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• 2023

CLC is used as a filling material for many buildings, and according to energy saving design standards, CLC also requires insulation performance. However, it shows lower insulation performance compared to organic insulation, so additional research is needed. Therefore, in this study, the insulation properties of CLC were analyzed by incorporating EPS beads with high insulation performance into CLC. In this experiment, EPS beads and blast furnace slag were replaced, and W/B was fixed at 33%. The EPS Bead mixing ratio was divided into 5 levels: 0, 0.5, 1.0, 1.5, 2.0 (%), and the experimental items were measured for apparent density and thermal conductivity. As a result of the experiment, the apparent density and thermal conductivity tended to decrease as the mixing ratio of EPS beads increased. It is judged that the density decreased due to the low density and the micropores inside, and the thermal conductivity also decreased.

• Journal of the Korea Institute of Building Construction
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• v.4 no.4
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• pp.79-86
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• 2004

The purpose of this study was the development of a recycling process to recover the hydraulic properties of hydration products which account for a large proportion of cementitious powder from concrete waste. This process was performed to recycle cementitious powder as recycle cement. Therefore, after the theoretical consideration of the properties of recycle process of recycled aggregates and cementitious powder, we investigated the hydraulic properties of cementitious powder under various temperature conditions in hardened mortar which was modeled on concrete waste. And we analyzed properties of chemical reactions of recycled cement with admixture materials such as Fly-Ash, Blast Furnace Slag As a result of the experiment, the most effective method to recover hydraulic properties of the cementitious powder from concrete waste was condition of burning at 700℃ for 120 minute. And it is shown that the fluidity of mortar was decreased rapidly when the burning temperature of recycle cement was increased. However, the compressive strength and fluidity were improved significantly when admixture materials such as Fly-Ash or Blast Furnace Slag was added.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.4
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• pp.721-728
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• 1994

The objective of this research is to analyze whether the ground granulated blast furnace (GGBF) slag, by-product of industry in domestic iron-foundary, can be useful as a mineral admixture for concrete by investigating physical and chemical property. In addition, according to making an fundamental experiment on mortar and concrete mixed with GGBF slag to some grade, examining the consistency, the compressive strength and the resistance to sulfate attack of concrete and mortar, the acquired results are that the compressive strength was increased and the resistance to sulfate attack was predominant.

• Computers and Concrete
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• v.21 no.2
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• pp.139-147
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• 2018

Due to enhanced construction requirement, ready mixed concrete are being popular day by day. The current study aimed to develop ready mixed concrete using GBFS contained cement and determine its properties of fresh and hardened states. A real scale experiment was set up in a ready mixed plant for measuring workability and compressive strength. The workability was tested after mixing (within 5 minutes), 30, 60, 90, 120 and 150 minutes of the running of bulk carrier. The ready mixed carrier employed spinning motion i.e., rotating around its axis with 20 RPM and running on road with 1km/h speed. The mixing ratio of cement: sand:gravel, water to cement ratio, super plasticizer were, 1:1.73:2.47, 0.40 and 6% of cement, respectively. The chemical composition of raw material was determined using XRF and the properties of cements were measured according to ASTM standards. The experimental results confirm that the cement with composition of 6.89% of GBFS, 4% of Gypsum and 89.11% of clinker showed the good compressive strength and workability of concrete after 150 minutes of the spinning motion in bulk carrier.

• Korean journal of applied entomology
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• v.26 no.1 s.70
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• pp.37-41
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• 1987

Sporulation potential and conidia release phase of Pyricularia oryzae on lesions under the natural conditions were measured in 1985 and 1986 leaf blast seasons. The amount of conidia produced in lesions on detached leaves and conidia released under the field condition were reached peak at $5{\sim}7$ days after lesion appearance. The maximum numbers of conidia produced and released were 16,200 and 15,900, respectively. Conidia release under the natural conditions lasted for 30 days.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.1
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• pp.59-68
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• 2008

The experiment was carried out to investigate the influence of coarse aggregate, admixture, and accelerator on the properties of concrete. As the maximum size of coarse aggregate decreased from 13 mm to 8 mm, fluidity of fresh concrete declined but compressive strength and dynamic modulus of elasticity of hardened concrete increased remarkably. The mechanical properties of concrete substituted silica fume to the plain concrete improved, the compressive strength of that substituted blast furnace slag increased slightly. The hydration reaction and compressive strength of specimen with sodium luminate type accelerator were high at initial, but specimen with alkali free type accelerator improved largely in 28 days.

• Korean Journal Plant Pathology
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• v.3 no.2
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• pp.120-123
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• 1987

Four types of spore trap (Kim's original, improved Kim's original, Yoshino's original and mixed type of Kim's and Yoshino's original) were evaluated for their efficacy to "estimate the amount of spores released from leaf blast lesions under the natural conditions. It was found that all four types had one or two defects in allowance for adequate sporulation/release, spore catch or spore counting. Thus, an improved type of spore trap was devised considering that it could cover the defects mentioned above. As a result, newly developed spore trap was quite satisfactory in above mentioned aspects and it could be used for pursuit of spore release phase under the natural conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.4
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• pp.404-408
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• 2003

This paper discusses the physical properties of permeable high quality concrete using blast furnace slag or steel slag as a part of aggregate. In the case of steel slag, aging treatment was adopted to prevent the volume expansion. With high range water reducing agent, the concrete using slag aggregate showed compressive strength up to 24MPa at the age of 28 days and the water permeability of the concrete was over the level of 0.1 m/s in this experiment. Also, there was no expansion problem in the concrete substituted with aged slag as a part of aggregate.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.196-197
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• 2013

This study is the experiment for manufacturing the Lightweight non-cement matrix based on the Blast furnace slag. And, the matrix was manufactured matrix by generating the bubble just by the reaction of KOH that is the alkali accelerator and paper ash, instead of the general foaming agent, that is the waste managed of incineration the pulp sludge generated in the process of manufacturing the paper. Consequently, the density according to the addition rate of KOH represented the tendency to increase. And it showed up that density of the matrix adding KOH 22.5% was the lowest. As to the strength test result, strength following addition rate of KOH increased. Since the bubble is generated in the reaction of KOH and paper ash, this shows the very low intensity but it is determined to be the result that the amount of vacant space is decreased because the bubble generated in the mixture process comes up as the specific gravity difference.