• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.584-587
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• 2004

This research investigates the rheological behavior and the confined water ratio of the cement paste and binder condition in order to predict mix design proportion of the high flowing concrete. The purpose of this study is to determine the optimum replacement ratio of binders including fly ash, and lime stone powder by the cement weight. For this purpose, belite cement, blast furnace slag cement and ordinary portland cement are selected. As test results, the confined water ratio shows the following range ; OPC>blast furnace slag cement>belite cement. Therefore, belite cement is proved very excellent cementitious materials in a view point of the flowability. The optimum replacement ratio of lime stone powder is shown over $30\%$ in case of belite cement and about $10\%$ in case of slag cement type. Also, the optimum replacement ratio of fly ash is shown $30\%$ by the cement weight considering the confined water ratio and deformable coefficient of the paste condition.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.3
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• pp.66-74
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• 2016

The aim of this research work is to investigate the mix proportion of multi-component cement incorporating ground granulated blast furnace(GGBFS), fly ash(FA) and silica fume(SF) as an addition to cement in ternary and quaternary combinations. The water-binder ratio was 0.45. In this study, 50% and 60% replacement ratios of mineral admixture to OPC was used, while series of combination of 20~40% GGBFS, 5~35% FA and 0~15% SF binder were used for fundamental characteristics tests. This study concern the GGBFS/FA ratio and SF contents of multi-component cement including the compressive strength, water absorptions, ultrasonic pulse velocity(UPV), drying shrinkage and X-ray diffraction(XRD) analysises. The results show that the addition of SF can reduce the water absorption and increase the compressive strength, UPV and drying shrinkage. These developments in the compressive strength, UPV and water absorption can be attributed to the fact that increase in the SF content tends basically to consume the calcium hydroxide crystals released from the hydration process leading to the formation of further CSH(calcium silicate hydrate). The strength, water absorption and UPV increases with an increase in GGBFS/FA ratios for a each SF contents. The relationship between GGBFS/FA ratios and compressive strength, water absorption, UPV is close to linear. It was found that the GGBFS/FA ratio and SF contents is the key factor governing the fundamental properties of multi-component cement.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.262-268
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• 1998

This research is to examine the selected method of optimal mixing proportion and cost analysis in the super flowing concrete. As confined water $ratio($\beta_p$)$ and K is introduced, itis to establish optimal mixing design of super flowing concrete according to the steps of paste, mortar and concrete. From paste and mortar test, it was led to $$\beta_p$$ and $K_p$satisfying the optimum condions depending on the kinds of binders. Then $$\beta_p$$ and $K_p$ is reflected to the mix condition of super flowing concrete. The result of test, the mix condition of super flowing concrete satisfied the quality performance of concrete with adjustment of additional rate of the superplasticizer. Besides, in case of design strength $350kg/\textrm{cm}^2$ of concrete, material cost in super flowing concrete is able to be reduced 5~16% in replacement of fly ash 30% in ordinary portland cement and slag cement.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.1
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• pp.76-83
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• 2012

In this study, the research examined the effect on FC, WG, RP replacement ratio on the quality improvement of BS mortar using the RA. First of all, the flow value increased as the FC contents increased, and decreased as the WG and RP contents increased. The air contents was reduced as the FC and RP contents increased, but was increased as the WG contents went up While the compressive strength of 1 : 7 mix proportion increased with the increase of the FC and WG contents, it decreased as there was more RP contents. The compressive strength of RP could increase as the mix proportion increased, but the difference depending on the improvement material type and replacement ratio decreased gradually. The absorption deteriorated as the FC and RP contents increased in all the mix proportions, but improved a little when WG was used. Meanwhile, the absorption decreased as the compressive strength improved in all the mix proportions as a correlation, but the order was FC, RP and WG depending on the quality improvement material types. The FC and WG were most favorable in terms of quality improvement as a total analysis, and the RP and WG was most effective in terms of economical efficiency and resource recycling.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.6
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• pp.796-806
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• 2015

To evaluate the effects of feeding linseed oil or/and sunflower oil mixed with fish oil on milk yield, milk composition and fatty acid (FA) profiles of dairy cows fed a high-concentrate diet, 24 crossbred primiparous lactating dairy cows in early lactation were assigned to a completely randomized design experiment. All cows were fed a high-concentrate basal diet and 0.38 kg dry matter (DM) molasses per day. Treatments were composed of a basal diet without oil supplement (Control), or diets of (DM basis) 3% linseed and fish oils (1:1, w/w, LSO-FO), or 3% sunflower and fish oils (1:1, w/w, SFO-FO), or 3% mixture (1:1:1, w/w) of linseed, sunflower, and fish oils (MIX-O). The animals fed SFO-FO had a 13.12% decrease in total dry matter intake compared with the control diet (p<0.05). No significant change was detected for milk yield; however, the animals fed the diet supplemented with SFO-FO showed a depressed milk fat yield and concentration by 35.42% and 27.20%, respectively, compared to those fed the control diet (p<0.05). Milk c9, t11-conjugated linoleic acid (CLA) proportion increased by 198.11% in the LSO-FO group relative to the control group (p<0.01). Milk C18:3n-3 (ALA) proportion was enhanced by 227.27% supplementing with LSO-FO relative to the control group (p<0.01). The proportions of milk docosahexaenoic acid (DHA) were significantly increased (p<0.01) in the cows fed LSO-FO (0.38%) and MIX-O (0.23%) compared to the control group (0.01%). Dietary inclusion of LSO-FO mainly increased milk c9, t11-CLA, ALA, DHA, and n-3 polyunsaturated fatty acids (PUFA), whereas feeding MIX-O improved preformed FA and unsaturated fatty acids (UFA). While the lowest n-6/n-3 ratio was found in the LSO-FO, the decreased atherogenecity index (AI) and thrombogenicity index (TI) seemed to be more extent in the MIX-O. Therefore, to maximize milk c9, t11-CLA, ALA, DHA, and n-3 PUFA and to minimize milk n-6/n-3 ratio, AI and TI, an ideal supplement would appear to be either LSO-FO or MIX-O.

• Magazine of the Korea Concrete Institute
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• v.8 no.3
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• pp.167-175
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• 1996

Recently, the mortar crack on floor is very serious in construction field, e.g. the crack due to plastic shrinkage and the crack due to drying shrinkage. To prevent this kind of crack, optimum mix proportions not only satisfying the required workability but also minimizing the unit water content were selected. And the expansion admixtures were used to compensate shrmkage of mortar. The water /cement ratio used in construction field is about 64% by the investigation. Even if the water /cement ratio of mortar is reduced, floor mortar is still able to have the required workability by the appropriate use of the fine aggregate with high fineness mo'dulus and superplastizer. The equations hetween mortar flow and water /cement ratio, sand /cement ratio, fineness modulus of fine aggregate were proposed in this study. And the proposed equation may provide available mix proportions of floor mortar.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.261-266
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• 1998

The purpose of this study is to present the reference data on the development of undispersed underwater mortar for augered pile under various replacement ratio of fly-ash. According to the experimental results, when 10% of fly-ash is mixed under mix proportion of 1:1.5(c:s), as strength and shrinkage decrease slightly, whereas fluidity increase, high quality mortar for augered pile can be achieve in case above condition is applied.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.10a
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• pp.50-55
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• 1995

Recently, high-workable concrete has been developed and began to be used to a great extent in foreign countries, but it isn't familiar with and fully introduced in Korea yet. The aim of this paper is to suggest a reference data for the development of High-workable concrete according to the comparative analysis the effect of mix proportion (unit water sand/aggregate ratio) on the flowing characteristics. And also this paper aims to examine the compactability of High-workable concrete in a model wall-form.

• Computers and Concrete
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• v.10 no.1
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• pp.19-33
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• 2012

The performance of a concrete is significantly influenced by its mixture proportion and the coating thickness on aggregate surface. The concrete in this study is designed by estimating the blending ratio of aggregate using a densified mixture design algorithm (DMDA) based on an ideal grading curve and estimating the paste volume as the sum of the amount of paste needed to provide an assigned coating paste thickness. So as to obtain appropriate concrete amount, and thus can accurately estimate the property of concrete. Deduction of this mix design formula is simple and easy understanding, and meanwhile to obtain result is fast. This estimation model of mix design is expected to reward to industry and effectively upgrade concrete quality.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.1
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• pp.57-66
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• 2014

The present study was conducted to provide basic data for environmentally friendly treatment of manure using vermicomposting. This was done by investigating the influence of physiochemical property change during the composting period on the survival of earthworms after mixing cow manure in different levels (0(CRH0), 10(CRH10), 20(CRH20), 30(CRH30), and 40%(CRH40)) with the rice hull that is generally added for composting manure. As composting proceeds, earthworms were able to survive in all conditions after 3 weeks. In terms of the C/N ratio by treatment groups, the rice hull mix treatments were significantly higher than the CRH0 treatment. Among rice hull mix treatments, the treatments with 30~40% rice hull level (CRH30 & CRH40) showed the highest ratio out of all composting periods (p<0.05). The C/N ratio in the 3rdweek when earthworms started surviving was 23.26~34.44. As composting progressed, pH and electrolytic conductivity (EC) were the highest in the CRH0 treatment (p<0.05) and tended to decrease with higher proportion of rice hull in the mix. It was found that pH and electrolytic conductivity (EC) that earthworms start to survive are 7.58~7.74 and 0.41~1.17 mS/cm, respectively. To summarize, when composing cow manure with various levels of rice hull mix, all physiochemical property changes turned out to allow the survival of earthworms, but the results suggest that efficient vermicomposting requires the tests to examine the growth and reproduction according to the rice hull mix ratio.