Freeze-thaw

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Freeze-thaw action on brick

Freeze-thaw action on brick

This paper deals mainly with those service conditions that affect freeze-thaw action, particularly the temperature changes experienced by a brick in a wall and th[r]

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Poromechanical behavior of cement-based materials subjected to freeze-thaw actions with salts : modeling and experiments

Poromechanical behavior of cement-based materials subjected to freeze-thaw actions with salts : modeling and experiments

Morphologically, the deformation of air-entrained cement pastes subjected to freeze-thaw loadings can be classified as three different sorts based on the characteristics of deformation curves, see Table 10.3 and top half of Figure 10.18 . For class I, no or slight nucleation deformation is followed by continual contraction and/or slight ex- pansion when temperature is cooled down to −35℃, and no significant residual deformation occurs. The slight nucleation deformation can be due to the energy change of ice formation, which is exactly the same reason for the dilation of porous materials when the benzene is used as saturating liquid as observed in [ 36 , 169 ]. The following contraction is due to the negative water pressure when the ice-water equilibrium is required at ice tip in pores [ 342 ]. The negative pressure is roughly proportional to depressed temperature as P l ≈ −1.2227∆T MPa [ 356 ]. As freezing goes on, some capillary pores are then partially occupied by ice, and the water in ’ink-bottle’ like pores is blocked. Once the blocked water crystallizes, the formed hydraulic pressure can cause damage eventually due to relatively slow pore pressure relaxation. In addi- tion, as illustrated in Figure 10.18 (a), the saturation degree of air void would increase continually with freeze-thaw cycles because the ice gem nucleated on the void-solid interface sucks the water in the adjacent capillary pore according to the cryosuction process.
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Characteristics of ultrasonic acoustic emissions from walnut branches during freeze–thaw-induced embolism formation

Characteristics of ultrasonic acoustic emissions from walnut branches during freeze–thaw-induced embolism formation

To distinguish UAEs generated by cavitation events in ves- sels from UAEs of other origins, the parameters of individ- ual freezethaw-induced UAEs were investigated for sample segments with three different ψ ranges (Table 1). Significant differences were observed for the parameters of counts, amplitude, and absolute energy among the three ψ ranges. High values of absolute energy were observed particularly in the ψ range from –1.3 MPa to –1.7 MPa (Table 1), in which the maximum loss of hydraulic conductivity by a freezethaw cycle was observed (Fig.  3). Under drought stress, a correlation between the energy of UAEs and xylem lumen dimensions has been observed (Mayr and Rosner, 2011; Ponomarenko et  al., 2014), probably because larger water conduits store higher total elastic energy (Ponomarenko et al., 2014). In freezethaw conditions, the formation of larger gas bubbles is expected in larger water conduits (Cruiziat et al., 2002). The larger bubbles might induce the release of higher tension, resulting in signals of higher energy. Compared with coniferous trees with narrow tracheids, the absolute energy for walnut branch segments with a ψ range from –1.3 MPa to –1.7 MPa was ~10 times that detected for P. contorta twigs partially dehydrated at a ψ of –3 MPa (Mayr and Sperry, 2010).
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Freeze/thaw mapping using SMAP data over the Canadian tundra : Sheldrake and Nastapoka (Turjusuk park).

Freeze/thaw mapping using SMAP data over the Canadian tundra : Sheldrake and Nastapoka (Turjusuk park).

Freeze/ Thaw mapping using SMAP data over the Canadian Tundra: Sheldrake and Nastapoka (Turjusuk park) Chaima Touati 1 , Tahiana Ratsimbazafy 1 , Monique Bernier 1 , Lingxiao Wang 2 , Ralf Ludwig 2 1 Institut national de la recherche scientifique, 2 Ludwig-Maximilians-Universität München

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Freeze-Thaw Stress: Effects of Temperature on Hydraulic Conductivity and Ultrasonic Activity in Ten Woody Angiosperms

Freeze-Thaw Stress: Effects of Temperature on Hydraulic Conductivity and Ultrasonic Activity in Ten Woody Angiosperms

UE have also been detected during freezing events, but the origin of these signals was less clear. In some cases, UE were observed during thawing, which are thus probably related to embolism formation according to the classic thaw-expansion hypothesis (Mayr and Sperry, 2010); however, all species studied have pro- duced UE on freezing, which cannot yet be explained (Raschi et al., 1989; Kikuta and Richter, 2003; Mayr et al., 2007; Mayr and Sperry, 2010; Mayr and Zublasing, 2010). The low solubility of gases in ice prompted the idea that air bubbles expulsed from the ice structure produce UE near the ice-liquid interface (Sevanto et al., 2012). As the water potential of ice is strongly temperature dependent, the minimum temperature during freezing might be a relevant factor. Numerous studies have an- alyzed UE patterns during freeze-thaw cycles in conifers
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Using available time series of passive and active microwave to develop smap freeze/thaw algorithms adapted for the Canadian Subarctic.

Using available time series of passive and active microwave to develop smap freeze/thaw algorithms adapted for the Canadian Subarctic.

the ability to sense the soil conditions through moderate land cover. The accuracy, resolution, and global coverage of the SMAP mission will make possible a systematic updating of frozen ground maps and monitoring the seasonal F/T cycle. The seasonal Freeze/Thaw (F/T) cycle plays an important role in Boreal and Arctic regions where structure, condition and distribution of vegetation are strongly regulated by environmental factors such as soil moisture and nutrient availability, permafrost, growing season length and disturbance [1, 2]. In these seasonally frozen environments, the growing season is determined primarily by the length of the non-frozen period. Variations in both timing of spring thaw and growing season length have a major impact on atmospheric-terrestrial carbon exchange in Boreal regions [3-6].
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Development of SMAP (soil moisture active and passive) Freeze/Thaw algorithms adapted for the Canadian Tundra.

Development of SMAP (soil moisture active and passive) Freeze/Thaw algorithms adapted for the Canadian Tundra.

Index Terms— SMAP, SMOS, Freeze/Thaw, Nunavik 1. INTRODUCTION The seasonal Freeze/Thaw (F/T) cycle is a major phenomenon in the climate system and plays an important role in ecosystem functioning [2] by influencing the rate of photosynthesis and respiration of the vegetation [11], reducing evaporation, reducing the penetration of water into the soil and altering surface runoff [2,11]. Boreal and arctic regions form a complex land cover mosaic where vegetation structure, condition and distribution are strongly regulated by environmental factors such as soil moisture and nutrient availability, permafrost, growing season length and disturbance. In these seasonally frozen environments, the growing season is determined primarily by the length of the non-frozen period. Variations in both the timing of spring thaw and the resulting growing season length have been found to have a major impact on terrestrial carbon exchange and atmospheric CO2 source/sink strength in boreal regions [13, 7, 8, and 14].
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Cavitation and water fluxes driven by ice water potential in Juglans regia during freeze–thaw cycles

Cavitation and water fluxes driven by ice water potential in Juglans regia during freeze–thaw cycles

Abstract Freezethaw cycles induce major hydraulic changes due to liquid-to-ice transition within tree stems. The very low water potential at the ice–liquid interface is crucial as it may cause lysis of living cells as well as water fluxes and embolism in sap conduits, which impacts whole tree–water relations. We investigated water fluxes induced by ice formation during freezethaw cycles in Juglans regia L. stems using four non-invasive and complementary approaches: a microdendrometer, magnetic resonance imaging, X-ray microtomography, and ultrasonic acous- tic emissions analysis. When the temperature dropped, ice nucleation occurred, probably in the cambium or pith areas, inducing high water potential gradients within the stem. The water was therefore redistributed within the stem toward the ice front. We could thus observe dehydration of the bark’s living cells leading to drastic shrink- age of this tissue, as well as high tension within wood conduits reaching the cavitation threshold in sap vessels. Ultrasonic emissions, which were strictly emitted only during freezing, indicated cavitation events (i.e. bubble for- mation) following ice formation in the xylem sap. However, embolism formation (i.e. bubble expansion) in stems was observed only on thawing via X-ray microtomography for the first time on the same sample. Ultrasonic emissions were detected during freezing and were not directly related to embolism formation. These results provide new insights into the complex process and dynamics of water movements and ice formation during freezethaw cycles in tree stems.
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Detailed detection of active layer freeze-thaw dynamics using quasi-continuous electrical resistivity tomography (Deception Island, Antarctica)

Detailed detection of active layer freeze-thaw dynamics using quasi-continuous electrical resistivity tomography (Deception Island, Antarctica)

The consistency of our full-year results with previous stud- ies in more easily accessible alpine and polar regions (e.g., Hilbich et al., 2011; Supper et al., 2014; Keuschnig et al., 2017; Tomaskovicova, 2018; Oldenborger and LeBlanc, 2018) suggests that the detailed studies of the Alps can be transferred to setups in very remote environments, which would allow for integrative process studies as well as cou- pled modeling of A-ERT data with existing water content and temperature monitoring systems in Antarctica. Exam- ples of such studies include the combination of data pro- cessing techniques, petrophysical models and supporting in- formation to estimate unfrozen water content from electri- cal resistivity data (e.g., Hauck, 2002; Fortier et al., 2008; Grimm and Stillman, 2015; Dafflon et al., 2016) or combin- ing electrical resistivity data with seismic refraction data in a joint petrophysical model to estimate ice and water content (e.g., Hauck et al., 2011). Such analyses also provide a tool for monitoring the transient layer and studying the impact of fast-changing meteorological conditions and the frequent freezethaw process on soil behavior at the permafrost ta- ble. However, in the context of the volcanic material at De- ception Island, the link between pore water resistivity and measured bulk resistivity should be assessed by laboratory measurements prior to performing a quantitative investiga- tion on soil ice and water content. In addition, the type of the electric conduction needs to be investigated, as in dry soils with low salinity, surface conduction is the dominant process (Duvillard et al., 2018), as opposed to electrolytic conduc- tion, which is usually assumed to calculate water contents from resistivity values.
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STUDYING WITH A FULL-FIELD MEASUREMENT TECHNIQUE THE LOCAL RESPONSE OF ASPHALT SPECIMENS SUBJECTED TO FREEZE- THAW CYCLES

STUDYING WITH A FULL-FIELD MEASUREMENT TECHNIQUE THE LOCAL RESPONSE OF ASPHALT SPECIMENS SUBJECTED TO FREEZE- THAW CYCLES

In this study, four Hot Mixtures Asphalt (HMA) specimens with 0%, 20%, 40% and 100% of RAP (Recycled Asphalt Pavement) content were considered. These materials were used in a previous study, which was devoted to the characterization of the effect of RAP on the local mechanical behavior of recycled asphalt pavements [6]. These RAP materials are composed of granite, basalt and gneiss. The virgin materials are constituted from limestone aggregates and a virgin bituminous binder. Freeze-thaw tests were carried out on these materials. They were performed in a climate chamber at

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Petroleum hydrocarbon biodegradation under seasonal freeze-thaw soil temperature regimes in contaminated soils from a sub-Arctic site

Petroleum hydrocarbon biodegradation under seasonal freeze-thaw soil temperature regimes in contaminated soils from a sub-Arctic site

from -5 to 4 °C at a thawing rate of +0.16 °C d -1 . In the unamended (control) tank, the F2 fraction only decreased by 14% during the same period. Biodegradation of individual hydrocarbon compounds in the nutrient-amended soils was also confirmed by comparing their abundance over time to that of the conserved diesel biomarker, bicyclic sesquiterpanes (BS). During this period, microbial respiration was observed, even at subzero temperatures when unfrozen liquid water was detected during the freeze-thaw period. An increase in culturable heterotrophs and 16S rDNA copy numbers was noted during the freezing phase, and the 14 C-hexadecane
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Mapping freeze/thaw cycle in Turjusuq Park using active and passive data.

Mapping freeze/thaw cycle in Turjusuq Park using active and passive data.

Boreal and arctic regions form a complex land cover mosaic where vegetation structure, condition and distribution are strongly regulated by environmental factors such as soil moisture and permafrost. The main purpose of our study is to map freeze/thaw cycle using passive and active data.

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Freeze-thaw durability of porous building materials

Freeze-thaw durability of porous building materials

Freeze-thaw durability of porous building materials Litvan, G. G. https://publications-cnrc.canada.ca/fra/droits L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.

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How does freeze-thaw affect solvent-based paints?

How does freeze-thaw affect solvent-based paints?

How does freeze-thaw affect solvent-based paints? O'Doherty, G. A.; Ashton, H. E. https://publications-cnrc.canada.ca/fra/droits L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.

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Particulate admixture for enhanced freeze-thaw resistance of concrete

Particulate admixture for enhanced freeze-thaw resistance of concrete

https://doi.org/10.1016/0008-8846(78)90057-1 Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Particulate admixture for enhanced freeze-thaw resistance of concrete Litvan, G. G.; Sereda, P. J.

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Moisture content and freeze-thaw cycles of masonry materials

Moisture content and freeze-thaw cycles of masonry materials

Moisture content and freeze-thaw cycles of masonry materials Ritchie, T.; Davison, J. I. https://publications-cnrc.canada.ca/fra/droits L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.

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Development of SMAP Freeze/Thaw algorithms adapted for the Canadian tundra.

Development of SMAP Freeze/Thaw algorithms adapted for the Canadian tundra.

Variability In Springtime Thaw In The Terrestrial High Latitudes: Monitoring A Major Control On The Biospheric Assimilation Of Atmospheric Co(2) With Spaceborne Microwave Remote Sensing. Earth Interactions, 8. Mcdonald, K. C., 2011, Mapping Global Wetlands And Boreal Freeze/Thaw With ALOS Palsar Science Team Meeting #16 – Phase 3 Kick-Off, Jaxa, Tsukuba/Tokyo, 17-21. Rignot, E., Way, J. B., Mcdonald, K., Viereck, L., Williams, C., Adams, P., Payne, C.,

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Preliminary evaluation of the freeze-thaw resistance of hydraulic lime mortars

Preliminary evaluation of the freeze-thaw resistance of hydraulic lime mortars

Preprint for the RILEM workshop on repair mortars for historic masonry 26-28 January 2005, Delft University, the Netherlands Abstract Hydraulic lime is regaining popularity in restoration work. This paper describes the results obtained from an initial assessment of mortar made using hydraulic limes available in Canada. The emphasis was on resistance to frost damage, a major consider- ation in Canada’s cold winters. The mortars, all air-entrained to improve frost resistance, were tested as part of small stone masonry specimens to more realistically simulate performance in practice (as opposed to mortar samples on their own). The frost dura- bility was assessed by subjecting the specimens to a uni-directional freeze-thaw test. The results show hydraulic lime mortars with air entrainment have the potential for good performance in terms of freeze-thaw resistance. Factors which influenced freeze-thaw resistance were the type and source of hydraulic lime, length of initial damp curing, mortar compaction, stone wetting before mortar application, and sand grading.
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Further study of particulate admixtures for enhanced freeze-thaw resistance of concrete

Further study of particulate admixtures for enhanced freeze-thaw resistance of concrete

5-Residual expansion as a function of the num- ber of freeze-thaw cycles of duplicate cement paste specimens (water-cement ratio = 0.48) with an without particulate admix[r]

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Special requirements for freeze/thaw resistance of concrete in PWR nuclear civil works

Special requirements for freeze/thaw resistance of concrete in PWR nuclear civil works

It is also acceptable to waive the requirement for the minimum air content for concrete exposed to frequent or very frequent attack from de-icing agents (XF2 or XF4) – in such case the scaling test according to XP P 18-420 [19] that is the same as „slab test” in PKN-CEN/TS 12390-9:2007 [15] should be performed. This procedure is also similar to the one expressed in PN-EN 1388:2005 except for number of cycles (increase from 28 to 56). The requirement is the mass of the scaling particles after 56 freeze-thaw cycles is M ≤ 600 g/m 2 . This value is different

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