• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.237-238
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• 2022

This study used Bacillus licheniformis generating glycocalyx as a provective membrane to enhance the salt-damage resistance of cement mortars. The mortar specimens with Bacillus licheniformis exhibited a comparable compressive strength development and 1.1~1.3 times higher dynamic modulus of elasticity under 300 freezing and thawing cycyles when compared with the counterpart control mortar.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.331-336
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• 1999

Permeable polymer concrete in this study is one of the environment conscious concrete that can be applied at road, side walks and river embankment, etc. The purpose of this study is to evaluate the effects of mix proportions such as resing content, filler-binder ratio and aggregate ratio on the freezing and thawing resistance of permeable polymer concrete. The permeable polymer concrete are prepared with the resin ratio of 5%, 6% and 7%, filler-binder ratio of 0, 0.5 and 1.0, and 2.5~5mm sized aggregate ratio to standard sand of 10:10, 10:20, 20:10 and 20:20. It is tested for freezing and thawing test according to ASTM C 666092, and then, weight change, length change, relative dynamic modulus, durability factor, and compressive and flexural strengths after test are measured. From the test results, the resistance to freezing and thawing of permeable polymer concrete increased with increase the resing content, filler-binder ratio and fine aggregate ratio.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.67-74
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• 2015

In this study, effects of micropores on the freezing-thawing resistance of high volume slag concrete are reviewed. Concrete was made with slag which contains the ground granulated blast furnace slag(GGBS) and the pig iron preliminary treatment slag(PS) by replacing 0, 40, 70 %, then compressive strength, freezing-thawing resistance, micropores were reviewed. Also, specified design strength, target air contents were set. Deterioration was induced by using 14-day-age specimen which has low compressive strength for evaluating deterioration by freeze-thawing action. As results of the experiment, despite of specified design strength which has been set similarly and ensured target air contents, the pore size distribution of the concrete showed different results. Micropores in GGBS70 specimen have small amount of water which is likely to freeze because there is small amount of pore volume of 10~100 nm size at 0 cycle which has not been influenced by freezing-thawing. For these reasons, it was confirmed that the freezing-thawing resistance performance of GGBS70 is significantly superior than other specimens because relatively small expansion pressure is generated compared to the other specimens.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.69-72
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• 2009

This research is focused on the applying of the foaming agent which can make the independent pore in the concrete structure in order to make a lightweight concrete structure. This lightweight foamed concrete can satisfy both the required strength and the mechanical properties as structural members. In addition, anti freezing-thawing properties also required. As a result of the unit volume-weight measurement, when the foaming agent mixed at 0.5% to 1%, the lightweight foamed concrete can be applied for the structural member. Also the density and compressive strength measurement results reveals that it will be suitable as structural member with 21MPa strength, when the density is betweenity8 to 1.9 and foaming agent quantities are 0.5% to 1%. Finally the result of freezing-thawing experiment, the effect freezing-thawing damage reduced according to adding foaming agent because those foaming agent make micro-pores in the structure which are not seen in the ordinary concrete structure.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.2
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• pp.59-66
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• 2006

This study is performed to evaluate freezing and thawing properties of polypropylene fiber reinforced eco-concrete using soil, natural coarse aggregate, soil compound and polypropylene fiber. The mass loss ratio is decreased with increasing the content of natural coarse aggregate and soil compound, but it is increased with increasing the content of polypropylene fiber. The ultrasonic pulse velocity, dynamic modulus of elasticity and durability factor are increased with increasing the content of natural coarse aggregate and soil compound, but it is decreased with increasing the content of polypropylene fiber. The mass loss ratio, ultrasonic pulse velocity, dynamic modulus of elasticity and durability factor are $1.49{\sim}3.32%,\;1,870{\sim}2,465\;m/s,\;77X10^2{\sim}225X10^2\;MPa\;and\;84.6{\sim}92.8$ after freezing and thawing 300 cycles, respectively. These eco-concrete can be used for environment-friendly side walk and farm road.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.687-692
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• 1998

This paper covers concrete durability made with portland cement type I and V, and granulated blast furnace slag blended cements 40 and 60%. Typical properties of cements and compressive strength development, drying shrinkage, carbonation, freezing and thawing properties of concretes were investigated. In addition, effects of CI penetration on various concretes with/without a freezing and thawing treatment were also studied. Portland cement type I and V were superior to the blended cement in the properties of compressive strength development, drying shrinkage, carbonation and freezing and thawing durability. In the respect of resistant of CI Blended cement showed better than the portland cement due to high permeability. But the blended cement with a freezing and thawing treatment presented a much decreased resistance of CI penetration.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.1
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• pp.45-54
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• 2003

The effects of binder content and silica sand content on the durability characteristics of lightweight polymer concretes are examined. As a result, the flame lingering times using unsaturated polyester resin and non-combustible polyester resin were 60∼120 and 0∼4 seconds respectively, and the combustion lengths were 9∼11 mm and 0∼3 mm, respectively. Thus it is believed that the lightweight polymer concrete was incombustible and the light weight polymer concrete in which non-combustible material was added was perfectly non-combustible. The percent of original mass of lightweight polymer concrete, according to the freezing-thawing experiment, was below 0.3 %, which was much less than that of cement concrete. The pluse velocity, for the case of the binder content 28 %, showed the minimum decreasing rate for the lightweight polymer concrete with silica sand content of 50 %. The higher the binder content, the greater the durability. That is much higher than other material and believed that the freezing-thawing was suppressed by a low absorption.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.185-188
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• 2001

In this study, the characteristics of freezing and thawing resistance, the compressive strength, and the change in height of cement mortar according to a steam and taler curing conditions has been studied. To this end, the major test variables include the period of the early curing, curing temperature and the later curing. The strength test as well as volume variousness have been conducted to explore the characteristics of freezing and thawing resistance on the curing conditions. The experimental results can be efficiently used to improve the characteristics of freezing and thawing resistance for concrete products carrying steam curing.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.736-742
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• 2009

This study was conducted to investigate the effect of various high pressure freezing and thawing treatments on the physical properties of pork. To compare the effects of the freezing and thawing process on meat quality, atmospheric freezing followed by running water thawing (AFRT), pressure shift freezing followed by running water thawing (SFRT), and pressure shift freezing and pressure assisted thawing (SFAT) were conducted at pressure of 250 MPa and cooling temperature of $-22^{\circ}C$. SAFT and SFRT showed a shorter phase transition time and total thawing time than AFRT. The pH value of treated samples increased significantly (p<0.05) compared to unfrozen meat. In addition, SFAT and SFRT showed a higher pHvalue than AFRT. Although the water holding capacity was significantly decreased (p<0.05) for SFAT and SFRT, SFRT reduced drip loss. In regards to color, SFAT and SFRT resulted in a significant increase in color parameters (p<0.05) relative to AFRT, while SFAT produced a higher L*-value. High pressure treatment significantly increased shear force (p<0.05) compared to AFRT, and, where SFRT showed the highest shear force. Therefore, these combined results indicated that the hydrostatic pressure treatment improved the functional properties of pork and increased the freezing and thawing rate.

• Journal of Industrial Technology
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• v.28 no.B
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• pp.65-69
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• 2008

The tailings piled in abandoned mines are well-known potential sources of soil contamination. Hydrated limes were applied as cementing materials to solidify heavy metal contaminated tailings for the purpose of reducing their toxicity and migration rates. The optimum mixing ratio of tailings, hydrated lime, and water was determined through a preliminary test. The mixtures of mine tailings and hydrated lime solidified through pozzolanic reaction were tested for their durability against repeated freezing and thawing processes. After repeated freezing and thawing, the uniaxial compressive strengths of all the solidified mixture specimens decreased in comparison with those before test but still higher than $3.5kgf/cm^2$, the standard recommended for land reclamation solids by EPA(Environmental Protection Agency), which suggested that hydrated lime be a potential material to treat the abandoned mine tailings for the environmental purpose.