• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 추계 학술논문 발표대회
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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.

• Smart Structures and Systems
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• 제17권1호
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• pp.45-58
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• 2016

Freezing and thawing cycles induce deterioration and strength degradation of concrete structures. This study presumes that a large quantity of contact-type defects develop due to the freezing and thawing cycles of concrete and evaluates the degree of defects based on a nonlinearity parameter. The nonlinearity parameter was obtained by an impact-modulation technique, one of the nonlinear ultrasonic methods. It is then used as an indicator of the degree of contact-type defects. Five types of damaged samples were fabricated according to different freezing and thawing cycles, and the occurrence of opening or cracks on a micro-scale was visually verified via scanning electron microscopy. Dynamic modulus and wave velocity were also measured for a sensitivity comparison with the obtained nonlinearity parameter. The possibility of evaluating strength degradation was also investigated based on a simple correlation of the experimental results.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.763-766
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• 1999

The objective of this study was to investigate the influence of low temperature curing on resistance of freezing and thawing of self-compacting concrete placed in cold weather regions. The experimental study results indicated that the self-compacting concrete incorporating ground granulated blast-furnace slag showed good resistance to freezing and thawing, and the self-compacting concrete cellulose viscous agent had relatively poor resistance to freezing and thawing.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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• pp.205-210
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• 1994

This study was conducted to evaluate performance of asphalt concretes under various densities, using Marshall specimens before and after freezing-and-thawing treatment. Six different compaction blows per side (20, 30, 40, 50, 60, 70 blows) were applied to specimens to produce different densities. Test results showed that the lower density specimens had the weaker resistance to freezing-and-thawing treatment. The density was an index of retaining fatigue life and displacement after freezing-and-thawing. Therefore, poor compaction in pavement was considered to be a major cause of early distress mechanisms such as rutting, ravelling and cracking, which were resulted in a reduced service life.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.625-631
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• 1999

In this study, a series of test was conducted to show the characteristics of freezing -thawing process on soilcrete using the soft clay in a redevelopment paddy area, was treated with cement and several additives such as Beestar, CaSO4 , MgO, and polypropylene fiber, From the results of test, it was found that first addtivies -cement and beestar-was effective for compressive strength, and the resistance against freezing -thawing process was improved by secondary additives, in the order their effectiveness, i.e. CaSO4 , Synthetic fiber, MgO and Beestar.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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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.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회논문집(II)
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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.

• 한국세라믹학회지
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• 제31권9호
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• pp.949-956
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• 1994

In order to investigate the relationship between pore size distribution and freezing-thawing resistance of mortars, polymer-cement mortars were prepared by using styrene-butadiene rubber latex, ethylene-vinyl acetate emulsion and polyacrylic ester emulsion with various polymer-cement ratios at constant flow. From the results of the test, polymer-cement mortars had a good pore size distribution for freezing-thawing resistance compared with unmodified mortars because of having a small pore volume in the pore radius range of 103~104 $\AA$ affecting on the frost damage. And the freezing-thawing resistance of polymer-cement mortars was improved with increasing polymer-cement ratio.

• 한국농공학회논문집
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• 제48권2호
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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.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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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.