Slag cements and frost resistance

2010 ◽  
pp. 785-790
Keyword(s):  
Frost Resistance

Features of radiothermoluminescence of polypropylene and ethylene propylenediene elastomer SKEPT-4044 compositions with nanoscale metal-containing fillers

2020 ◽  
pp. 66-73
Author(s):  
A.M. Magerramov ◽  
◽  
N.I. Kurbanova ◽  
M.N. Bayramov ◽  
N.A. Alimirzoyeva ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Molecular Mobility ◽  
Fe3o4 Nanoparticles ◽  
Low Temperatures ◽  
Frost Resistance ◽  
Relaxation Processes ◽  
Ethylene Propylene ◽  
Temperature Range ◽  
Β Relaxation

Using radiothermoluminescence (RTL), the molecular mobility features in the temperature range of 77-300 K were studied for the polypropylene (PP)/ethylene propylene diene elastomer SKEPT-4044 with NiO, Cu2O and Fe3O4 nanoparticles (NPs) based on ABS-acrylonitrile butadiene or SCS-divinyl styrene matrices. It has been shown that the introduction of nanofillers in PP significantly affects the nature and temperature of γ- and β-relaxation processes, while the region of manifestation of the β-process noticeably shifts to the region of low temperatures. Composites with Cu2O NPs have a higher β-transition temperature Tβ than composites with other NPs. It was found that PP/SKEPT-4044 composites with Cu2O NPs with a dispersion of 11-15 nm and acrylonitrile butadiene thermoplastics have optimal frost resistance compared to other compositions.

Influence of Electro-Surface Properties of Mineral Filler on Frost Resistance of Powder Concretes

2019 ◽  
Vol 775 (10) ◽  
pp. 12-15
Author(s):  
Sh.M. RAKHIMBAEV ◽  
◽  
N.M. TOLYPINA ◽  
A.A. KOSINOVA ◽  
E.N. KHAKHALEVA ◽  
...  
Keyword(s):  
Surface Properties ◽  
Frost Resistance ◽  
Mineral Filler

Cereals frost resistance correlates with an integral indicators of content of low-molecular-weight protective compounds and activity of antioxidant enzymes

2020 ◽  
Vol 2020 (3) ◽  
pp. 71-86
Author(s):  
O. I. Horielova ◽  
◽  
N. I. Ryabchun ◽  
M. A. Shkliarevskyi ◽  
A. M. Reznik ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Superoxide Dismutase ◽  
Antioxidant Enzymes ◽  
Antioxidant System ◽  
Frost Resistance ◽  
Low Molecular Weight ◽  
Guaiacol Peroxidase ◽  
Wheat Seedlings ◽  
Enzymatic Antioxidant ◽  
Adult Plants

Along with specific adaptive reactions, universal defense reactions, in particular activation of antioxidant system, are of great importance for plant survival under cold conditions. We have studied a relationship among the content of low-molecular-weight protective compounds with antioxidant properties (proline, soluble carbohydrates, flavonoids), the activity of antioxidant enzymes (superoxide dismutase, catalase, and guaiacol peroxidase) in seedlings of winter wheat, rye and triticale, and frost resistance of etiolated seedlings and adult plants at tillering stage. It was found that there was a fairly close correlation between the frost resistance of seedlings and adult cereal plants (r = 0,78). It was shown that a pronounced relationship between individual indicators of antioxidant system functioning in unhardened seedlings and their frost resistance was not found. After 6-day hardening of seedlings at 2-4°C, there was a high correlation between the total indicator of the enzymatic antioxidant system (the sum of normalized indicators of superoxide dismutase, peroxidase, and catalase activity) and their frost resistance (r = 0,86), but the correlation coefficient of this index with frost resistance of plants in tillering phase was significantly lower (r = 0,47). At the same time, a high correlation was found between the content of low-molecular-weight protectors in hardened seedlings and frost resistance of tillering adult plants (r = 0.89). The closest correlation was observed between the integral normalized indicator, comprising the sum of normalized values of antioxidant enzymes activity and the content of low-molecular-weight protectors in hardened seedlings, and frost resistance of seedlings (r = 0,94) and plants in tillering phase (r = 0,89). A presence of specific features in the functioning of antioxidant system during cold adaptation of cereal seedlings was established. Rye is characterized by a high content of low-molecular-weight protective compounds; at the same time, increased activity of antioxidant enzymes - superoxide dismutase and catalase - was noted in wheat seedlings. In triticale, depending on the genotype, the values of both enzymatic antioxidant activity and the content of low-molecular-weight protectors varied.

Bestimmung der Dauerhaftigkeit von Hochleistungsbeton mit Hilfe des CDF-Tests / Determination of the durability of high performance concrete by means of CDF-test

1999 ◽  
Vol 5 (1) ◽  
pp. 29-40
Author(s):  
R. Krumbach ◽  
U. Schmelter ◽  
K. Seyfarth
Keyword(s):  
Frost Resistance ◽  
High Strength Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Strength Concrete ◽  
Factors Influencing

Abstract Variable obsen>ations concerning frost resistance of high performance concrete have been made. The question arises which are the decisive factors influencing durability under the action of frost and de-icing salt. The proposed experiments are to be carried out in cooperation with F.A.- Finger - Institute of Bauhaus University Weimar. The aim of this study is to determine possible change of durability of high strength concrete, and to investigate the origin thereof. Measures to reduce the risk of reduced durability have to be found.

Increase of frost resistance capacity of clay roofing tiles with boron waste addition

2021 ◽  
Vol 280 ◽  
pp. 122493
Author(s):  
Angeliki Christogerou ◽  
Paraskevi Lampropoulou ◽  
Efstathios Panagiotopoulos
Keyword(s):  
Frost Resistance

Frost resistance of internal curing concrete with calcined natural zeolite particles

2021 ◽  
Vol 288 ◽  
pp. 123062
Author(s):  
Xuan Zheng ◽  
Jun Zhang ◽  
Xiaoping Ding ◽  
Hewei Chu ◽  
Jiajia Zhang
Keyword(s):  
Frost Resistance ◽  
Natural Zeolite ◽  
Internal Curing

Studies the Properties of Polyaspartic Polyurea Coated Concrete under Coaction of Salt Fog and Freeze-Thaw

2012 ◽  
Vol 455-456 ◽  
pp. 781-785
Author(s):  
Ping Lu ◽  
Xin Mao Li ◽  
Xue Qiang Ma ◽  
Wei Bo Huang
Keyword(s):  
Elastic Modulus ◽  
Frost Resistance ◽  
Dynamic Elastic Modulus ◽  
Freeze Thaw ◽  
Decrease Rate ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Salt Fog

. This paper mainly studied the properties of PAE polyurea coated concrete under coactions of salt fog and freeze-thaw. After exposed salt fog conditions for 200d, T3, B2, F2 and TM four coated concrete relative dynamic elastic modulus have small changes, but different coated concrete variation amplitude is different. T3 coated concrete after 100 times of freeze-thaw cycle the relative dynamic elastic modulus began to drop, 200 times freeze-thaw cycle ends, relative dynamic elastic modulus variation is the largest, decrease rate is 95%, TM concrete during 200 times freeze-thaw cycle, relative dynamic elastic modulus almost no change, B2 concrete and F2 concrete the extent of change between coating T3 and TM. After 300 times the freeze-thaw cycle coated concrete didn't appear freeze-thaw damage phenomenon. Four kinds of coating concrete relative dynamic elastic modulus variation by large to small order: T3 coated concrete > B2 coated concrete >F2 coated concrete > TM coated concrete, concrete with the same 200d rule. Frost resistance order, by contrast, TM coated concrete > B2 coated concrete > F2 coated concrete > T3 coated concrete.

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