• Food Science of Animal Resources
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• v.26 no.1
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• pp.1-8
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• 2006

To investigate the effect of ${\beta}$-hydroxyacyl CoA-dehydrogenase(HADH) activity increased by freezed and thaw process on myoglobin(Mb) oxidation without lipid oxidation during, pork loins were collected at postmortem 24 hts and sliced to steaks (3 cm thickness). Samples were packaged in a polyethylene bag and subjected to flesh group (control), one cycle fieezed and thaw group (treatment 1) and two cycles freezed and thaw group (treatment 2), respectively. Samples were measure meat color (CIE $L^*,\;a^*,\;b^*$), the contents(%) of MetMb, thiobarbituric acid reactive substance (TBARS) value and HADH(${\beta}$-hydroxyacyl CoA-dehydrogenase) activity at 0, 3, and 7 days of storage at $4^{\circ}C$. Both treatments showed significantly (p<0.05) lower $L^*$ and higher $L^*$ value compared to those of control at 7 days. On the contrary, MetMb contents(%) of treatments were significantly (p<0.05) higher than those of control during cold storage. However there were no significant (p> 0.05) differences in TBARS values between control and treatments during 7 days. There were significant (p<0.05) differences in HADH activity between control and treatments at 3 days of cold storage. Both treatments showed higher HADH activity compared to those of control. These results suggested that the freezed and thaw process could accelerate meat color deterioration, i.e. increased MetMb percentage without lipid oxidation in pork loin during cold storage. This also implied that autoxidation of Mb in freezed and thaw pork loin was influenced by enzyme-catalysed reactions in the tissue that would lead to decreased OxyMb.

• Journal of Environmental Science International
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• v.13 no.2
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• pp.143-148
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• 2004

In this paper, the properties of inter - locking block using fly ash are discussed in order to provide economical advantages and improve quality, and protect environment and recycle resources. Fly ash is the by-product of coal in thermal power plant. The experimental parameters are fly ash content, the amount of AE water - reducing agent and mixing proportion of cement mortar. According to the experimental results, the improvement of quality in the side of strength, absorption ratio and freeze - thaw resistance for manufacturing inter -locking block and the curtailment of cost can be achieved in case of 15% of fly ash and 0.3% of AE water- reducing agent are mixed into mortar mixture of 1 :6(C:S).

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.765-770
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• 2001

Concrete curbing blocks have been widely used in construction of roadways because they are easy too manufacture and cheap. But recently stone curbs are taking away the role from concrete curbs, because the durability of concrete curbs is inferior to stone curbs. Especially freeze-thaw effect on concrete is the most important cause that damages concrete curbs. The aim of this study is to increase the durability of concrete curbs. The concrete curbs that have been manufactured are extremely damaged below 60 cycles of freeze-thaw, but the ones that was manufactured with admixtures that entrains air are maintaining over 87% of relative dynamic modulus.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.372-375
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• 2004

Scaling deterioration and resistance to freezing of port concrete structures due to the combined effects of chemical actions by containning chlorides and the freeze-thaw action is also a problem which has not yet been fundamentally solved. Furthermore, deterioration of concrete surface was considered as accelerate factor of concrete durability tended to decrease. Therefore, we considered the scaling measuring method and decreasing influence of durability of concrete according to kind of binders, such as OPC, Slag, Slag+Fa, due to freeze and thaw of concrete by containing chlorides. As a results of this study, it was effective method of scaling deterioration and resistance freewing of concrete, and confirmed the salt deterioration resistance effect to use slag binder against to containing chlorides.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.1
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• pp.116-124
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• 2002

Natural resources fur the construction materials such as good soil, sand, and coarse aggregates have been encountered to be short due to excessive use by human. Even though some soil has been found to be unsuitable for construction materials, soil with reinforcement can naturally be an answer to these alternatives. According to recently published papers on fiber mixed soil, fiber mixed with soil can improve shear strength, compressive strength and post-peak load strength retention. In this study, a series of tests were performed to clarify the characteristics of fiber mixed soil and to give basic data for design and construction and their engineering properties, that is, unconfined compressive strength, splitting tensile strength, shear strength, crack by drying, freeze-thaw, creep and Poisson\`s ratio, were investigated and analyzed. It has been shown that fiber mixed soil is one of good alternatives fur the civil and building construction materials.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.2
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• pp.19-25
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• 2010

This study was conducted to determine the resilient modulus (Mr) and the unconfined compressive strength (UCS) of two recycled roadway materials such as recycled pavement material (RPM) and road surface gravel (RSG) with or without cement kiln dust (CKD). The recycled materials were blended with two CKD contents (5, 10 %) and 28 day curing time. Mr and UCS tests were also conducted after 10cycles of freezing and thawing to asses the impact of freeze-thaw cycling. Mr was determined conducting by the laboratory test method described by NCHRP 1-28A. Stabilized RPM and RSG had a modulus and a strength higher than unstabilized RPM and RSG. Mr and UCS of RPM and RSG mixed with CKD increased with increasing CKD content. The results indicated that the addition of CKD could be improved the strength and the stiffness of RPM and RSG. Therefore, RPM, RSG and CKD could be used as an effective materials in the reconstruction of roads.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.497-502
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• 2000

This study was performed to change the latex content for properties of freezing-thawing resistance. When styrene-butadiene latex is added to portland cement, aggregate and water, a concrete with the color, consistency and workability of ordinary conventional concrete results, but with 20% to 35% less water. When cured, the concrete consists of hydrated cement and aggregate interconnected by a film of latex particles. In general, increasing the amount of latex will produce concrete with increased tensile and flexural strength and lower modulus of elasticity. Air entrainment has been used in conventional concrete for the past 50 years to impart freeze-thaw resistance. Latex modified concrete does not need additional air entrainment for freeze-thaw resistance provided adequate cure occurs.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.559-562
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• 2005

The purpose of this study is to evaluate the durability and bond strength of polymer powder-modified mortars with special accelerator components. The mortars were prepared with various polymer-binder ratios and applied to the concrete substrate as a repair material. Bond strength, flexural and compressive strengths, freeze-thaw resistance and carbonation resistance were measured for the test. As a result, bond strength of the mortars was increased with an increase in the polymer-cement ratio, and freeze-thaw resistance and carbonation resistance were significantly improved with increasing polymer-cement ratio also.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.371-374
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• 2005

In this study, calcium chloride($CaCl_2$), sodium chloride (NaCl), organic acids-containing deicer(NS 40, NS 100), mixed deicier($NaCl\;70\%\;+\;CaCl_{2}\;30\%,\;NS\;40\;70\%\;+\;CaCl_{2}\;30\%,\;NaCl\;70\%\;+\;NS\;40\;30\%,\;NS\;40\;70\%\;+\;NaCl\;30\%$) is investigated based on the laboratory test for deicing performance. Test items for deicing performance were ice melting and ice penetration, freezing point depressions and eutectic points, pH, thermal properties for selected deicing chemicals. As a test results, in case of the use chloride-containing deicier in area that concrete structures has subjected to freez-thaw reaction in winter season, it showed desirable method that use deicing chemicals mixed with optimum ratio rather than use one deicing chemicals when is consider to deicing performance and effects, corrosion of steel materials, freez-thaw resistance of concrete. When use various deicing chemicals mixed, NS40($70\%$)+Calcium chloride($30\%$) showed the best effective method.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.211-212
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• 2010

This study is aimed to investigate effects of water-cement ratio on the freeze thaw resistance of fly ash concrete. Assess the effects of physical properties of fly ash concrete by measure the length change, weight change, dynamic modulus of elasticity.