Experimental Study on Freeze-Thaw Cycle Duration of Saturated Tuff

The freeze-thaw duration is one of the important factors affecting the change of rock properties. However, this factor has not formed a unified standard in the freeze-thaw cycle test. This study uses saturated tuff samples taken from eastern Zhejiang, China, as research objects to explore the change law of the time required for the rock to reach a full freeze-thaw cycle. Measured results show that the total duration of the freeze-thaw cycle presents an increasing power function with the increase in the number of freeze-thaw cycles. The freezing process is divided into three phases: initial freezing, water-ice phase transition, and deep freezing. The melting process is also divided into three phases: initial melting, ice-water phase transition, and deep melting. The time required for the ice-water phase change stage of the melting process does not change with the increase in the number of freeze-thaw cycles, while the other stages increase as a power function. The proportion of duration of each stage in the freezing process does not change with the increase in the number of cycles. By contrast, the duration proportion of the initial melting phase in the melting process decreases, and the deep melting phase increases. Experimental results of the freeze-thaw cycles of tuff demonstrate that the freeze-thaw duration of the freeze-thaw cycles within 40 times can be set to 9 h. The freezing and melting processes are 6 and 3 h, respectively.

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Strength and Microscopic Damage Mechanism of Yellow Sandstone with Holes under Freezing and Thawing

Advances in Civil Engineering ◽

10.1155/2020/5921901 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

Huren Rong ◽

Jingyu Gu ◽

Miren Rong ◽

Hong Liu ◽

Jiayao Zhang ◽

...

Keyword(s):

Mechanical Properties ◽

Pore Size ◽

Power Function ◽

Damage Mechanism ◽

Uniaxial Compression Test ◽

Freezing And Thawing ◽

Freeze Thaw ◽

Thaw Cycle ◽

Freeze Thaw Cycle ◽

Microscopic Damage

In order to study the damage characteristics of the yellow sandstone containing pores under the freeze-thaw cycle, the uniaxial compression test of saturated water-stained yellow sandstones with different freeze-thaw cycles was carried out by rock servo press, the microstructure was qualitatively analyzed by Zeiss 508 stereo microscope, and the microdamage mechanism was quantitatively studied by using specific surface area and pore size analyzer. The mechanism of weakening mechanical properties of single-hole yellow sandstone was expounded from the perspective of microstructure. The results show the following. (1) The number of freeze-thaw cycles and single-pore diameter have significant effects on the strength and elastic modulus of the yellow sandstone; the more the freeze-thaw cycles and the larger the pore size, the lower the strength of the yellow sandstone. (2) The damage modes of the yellow sandstone containing pores under the freeze-thaw cycle are divided into five types, and the yellow sandstone with pores is divided into two areas: the periphery of the hole and the distance from the hole; as the number of freeze-thaw cycles increases, different regions show different microscopic damage patterns. (3) The damage degree of yellow sandstone is different with freeze-thaw cycle and pore size. Freeze-thaw not only affects the mechanical properties of yellow sandstone but also accelerates the damage process of pores. (4) The damage of the yellow sandstone by freeze-thaw is logarithmic function, and the damage of the yellow sandstone is a power function. The damage equation of the yellow sandstone with pores under the freezing and thawing is a log-power function nonlinear change law and presents a good correlation.

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A Freezing-Thawing Damage Characterization Method for Highway Subgrade in Seasonally Frozen Regions Based on Thermal-Hydraulic-Mechanical Coupling Model

Sensors ◽

10.3390/s21186251 ◽

2021 ◽

Vol 21 (18) ◽

pp. 6251

Author(s):

Qingsong Deng ◽

Xiao Liu ◽

Chao Zeng ◽

Xianzhi He ◽

Fengguang Chen ◽

...

Keyword(s):

Rapid Development ◽

Coupling Model ◽

Frozen Soil ◽

Mechanical Coupling ◽

Damage Area ◽

Freeze Thaw ◽

Thaw Cycle ◽

Freeze Thaw Cycle ◽

Ice Content ◽

Ice Water

Seasonally frozen soil where uneven freeze–thaw damage is a major cause of highway deterioration has attracted increased attention in China with the rapid development of infrastructure projects. Based on Darcy’s law of unsaturated soil seepage and heat conduction, the thermal–hydraulic–mechanical (THM) coupling model is established considering a variety of effects (i.e., ice–water phase transition, convective heat transfer, and ice blocking effect), and then the numerical solution of thermal–hydraulic fields of subgrade can be obtained. Then, a new concept, namely degree of freeze–thaw damage, is proposed by using the standard deviation of the ice content of subgrade during the annual freeze–thaw cycle. To analyze the freeze–thaw characteristics of highway subgrade, the model is applied in the monitored section of the Golmud to Nagqu portion of China National Highway G109. The results show that: (1) The hydrothermal field of subgrade has an obvious sunny–shady slopes effect, and its transverse distribution is not symmetrical; (2) the freeze–thaw damage area of subgrade obviously decreased under the insulation board measure; (3) under the combined anti-frost measures, the maximum frost heave amount of subgrade is significantly reduced. This study will provide references for the design of highway subgrades in seasonally frozen soil areas.

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Numerical Modeling of the Tissue Freezing-Thaw Cycle During Cutaneous Cryosurgery Using Liquid Nitrogen Spray

Heat Transfer, Part A ◽

10.1115/imece2005-82859 ◽

2005 ◽

Cited By ~ 4

Author(s):

Feng Sun ◽

G.-X. Wang ◽

K. M. Kelly ◽

G. Aguilar

Keyword(s):

Liquid Nitrogen ◽

Human Skin ◽

Thermal History ◽

Tissue Temperature ◽

Freezing Process ◽

Target Tissue ◽

Freeze Thaw ◽

Membrane Rupture ◽

Thaw Cycle ◽

Freeze Thaw Cycle

It is common in some cryosurgical procedures to rely on freeze-thaw cycle(s) to destroy undesirable tissues. Most research in cryosurgery focuses on the freezing process and much less attention has been paid to thawing or re-warming. However, as ice melts during thawing, the extracellular solution can become locally hypotonic, driving water into cells, resulting in cell expansion and ultimately, membrane rupture. Therefore, the thermal history of the target tissue during both the freezing and thawing processes is critical for cell viability. To better understand and predict the thermal history during cryosurgery, we developed a two-dimensional numerical model to describe the complete freeze-thaw cycle during liquid nitrogen cutaneous cryosurgery. A stratified anatomical structure of human skin is considered in the model. The numerical simulation applies temperature-dependent thermal and physical properties for human skin tissue and considers the typical thermal boundary conditions for clinical practice. Parametric studies are performed to explore the influence of spray cooling, spray duration and surface heating. Results are discussed concentrating on iceball front propagation, lethal temperature isotherm evolution, tissue temperature variation and cooling rates. These results are expected to provide both quantitative and graphical support to cutaneous cryosurgery and suggest approaches to optimize current cryosurgical protocols.

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Experimental investigation on combined modification for micro physicochemical characteristics of coal by compound reagents and liquid nitrogen freeze-thaw cycle

Fuel ◽

10.1016/j.fuel.2021.120287 ◽

2021 ◽

Vol 292 ◽

pp. 120287

Author(s):

Weibo Han ◽

Gang Zhou ◽

Junpeng Wang ◽

Wenjing Jiang ◽

Qian Zhang ◽

...

Keyword(s):

Experimental Investigation ◽

Liquid Nitrogen ◽

Physicochemical Characteristics ◽

Freeze Thaw ◽

Thaw Cycle ◽

Freeze Thaw Cycle

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The effect of freeze–thaw cycle on the low-temperature properties of asphalt fine aggregate matrix utilizing bending beam rheometer

Cold Regions Science and Technology ◽

10.1016/j.coldregions.2016.02.008 ◽

2016 ◽

Vol 125 ◽

pp. 101-107 ◽

Cited By ~ 20

Author(s):

Xiangbing Gong ◽

Pedro Romero ◽

Zejiao Dong ◽

Daniel Scott Sudbury

Keyword(s):

Low Temperature ◽

Fine Aggregate ◽

Bending Beam Rheometer ◽

Freeze Thaw ◽

Thaw Cycle ◽

Freeze Thaw Cycle ◽

Fine Aggregate Matrix

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Effect of freeze–thaw cycle on physical and mechanical properties and damage characteristics of sandstone

Scientific Reports ◽

10.1038/s41598-021-91842-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Longxiao Chen ◽

Kesheng Li ◽

Guilei Song ◽

Deng Zhang ◽

Chuanxiao Liu

Keyword(s):

Mechanical Properties ◽

Shear Failure ◽

Triaxial Compression ◽

Physical And Mechanical Properties ◽

Freeze Thaw ◽

Damage Characteristics ◽

Large Pore ◽

Natural Rock ◽

Thaw Cycle ◽

Freeze Thaw Cycle

AbstractRock deterioration under freeze–thaw cycles is a concern for in-service tunnel in cold regions. Previous studies focused on the change of rock mechanical properties under unidirectional stress, but the natural rock mass is under three dimensional stresses. This paper investigates influences of the number of freeze–thaw cycle on sandstone under low confining pressure. Twelve sandstone samples were tested subjected to triaxial compression. Additionally, the damage characteristics of sandstone internal microstructure were obtained by using acoustic emission (AE) and mercury intrusion porosimetry. Results indicated that the mechanical properties of sandstone were significantly reduced by freeze–thaw effect. Sandstone’ peak strength and elastic modulus were 7.28–37.96% and 6.38–40.87% less than for the control, respectively. The proportion of super-large pore and large pore in sandstone increased by 19.53–81.19%. We attributed the reduced sandstone’ mechanical properties to the degenerated sandstone microstructure, which, in turn, was associated with increased sandstone macropores. The macroscopic failure pattern of sandstone changed from splitting failure to shear failure with an increasing of freeze–thaw cycles. Moreover, the activity of AE signal increased at each stage, and the cumulative ringing count also showed upward trend with the increase of freeze–thaw number.

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Non-linear creep damage model of sandstone under freeze-thaw cycle

Journal of Central South University ◽

10.1007/s11771-021-4656-3 ◽

2021 ◽

Vol 28 (3) ◽

pp. 954-967

Author(s):

Jie-lin Li ◽

Long-yin Zhu ◽

Ke-ping Zhou ◽

Hui Chen ◽

Le Gao ◽

...

Keyword(s):

Damage Model ◽

Creep Damage ◽

Freeze Thaw ◽

Thaw Cycle ◽

Linear Creep ◽

Non Linear ◽

Freeze Thaw Cycle ◽

Creep Damage Model

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.455-456.781 ◽

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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