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1
Ma, Yin Hua, and Jian Yi Gu. "Study on Freeze-Thaw Performance of Polypropylene Fiber Reinforced Cement-Stabilized Aggregate." Advanced Materials Research 446-449 (January 2012): 2595–98. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.2595.
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In this paper, the authors study the anti-freeze-thaw performance of a new type of semi-rigid base material named polypropylene fiber reinforced cement-stabilized aggregate, and freeze-thaw mass loss rate, freeze-thaw compressive strength, freeze-thaw splitting strength are used to evaluate the effect of polypropylene fiber on the anti-freeze-thaw performance, and the relationship of polypropylene fiber content, polypropylene fiber length with the anti-freeze-thaw performance are analyzed. The test after 10 freeze-thaw cycle shows that the mix of polypropylene fiber increase the freeze-thaw compressive strength and freeze-thaw splitting strength, and decrease the mass loss rate greatly. At the same time, the paper also determine the reasonable fiber content and fiber length, under this mix proportion, the mass loss rate reduce by 80%, the freeze-thaw compressive strength increase more than 12.1% and freeze-thaw splitting strength increase more than 13.4%. This research has laid an important foundation for the follow-up research and practice.
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Zhang, Changjun. "Freeze-thaw batteries." Nature Energy 7, no. 5 (May 2022): 386. http://dx.doi.org/10.1038/s41560-022-01047-0.
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Franks, Felix. "Freeze/Thaw Isolation." Nature Biotechnology 13, no. 3 (March 1995): 200. http://dx.doi.org/10.1038/nbt0395-200b.
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Zhang, Hui Mei, Geng She Yang, and Yuan Liang. "Experimental Study on Damage Deterioration and Tensile Characteristics of Rock under Freeze-Thaw Environment." Advanced Materials Research 518-523 (May 2012): 1749–52. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.1749.
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The basic mechanical problem facing of environmental geotechnical engineering in cold regions is the physical and mechanical properties of rocks under freeze-thaw conditions. The freeze-thaw cycling experiment was conducted first for two types of rock which are red sandstone and shale, then the splitting tensile experiment on different freeze-thaw cycles. The damage deterioration and breaking behavior under freeze-thaw conditions was investigated, and the influence of lithology and freeze-thaw cycle on anti-tensile characteristics of rock was studied. It is shown that three freeze-thaw damage deterioration modes of two kinds of rock are spalling mode, fracture mode and crack mode. The freeze-thaw cycle leads to irreversible deterioration on physical and mechanical properties for rock, but the damage of red sandstone is more serious than that of shale by the number of freeze-thaw cycles. The regularity of freeze-thaw effects of compression and tensile characteristics for two rocks are identical, but the tensile characteristic is more sensitive to freeze-thaw cycle.
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Li, Leiming, and Jun Wu. "Lead and Chromium Immobilization Process Subjected to Different Freeze-Thaw Treatments in Soils of the Northeastern Qinghai-Tibet Plateau." Journal of Chemistry 2021 (October 21, 2021): 1–11. http://dx.doi.org/10.1155/2021/5286278.
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The freeze-thaw cycle is one of the important processes that affected heavy metal behaviors in soil. However, information regarding the adsorption and desorption behavior of heavy metals in soils under different freeze-thaw conditions is relatively less. Therefore, different freeze-thaw conditions including unfrozen, 15 freeze-thaw cycles at 60% water content, and 15 freeze-thaw cycles at 100% water content were investigated. Then the adsorption and desorption behaviors of Pb and Cr in freeze-thaw soils were studied. Results showed the Pb and Cr adsorption amount mostly decreased with increasing water-soil ratio, and the soil performance of Pb and Cr adsorption at same water-soil ratios showed variation under different freeze-thaw conditions. The Pb isothermal adsorption was higher for most freeze-thaw treatments compared to the control. The soil performance of Cr isothermal adsorption showed variation under different freeze-thaw conditions. Most electrostatic binding of Pb and Cr were stronger under unfrozen and freeze-thaw conditions than unfrozen conditions. Most Pb and Cr adsorption kinetics patterns of freeze-thaw treated soils were rapid than unfrozen conditions. These results implied that freeze-thaw cycles could change the soil adsorption and desorption patterns of Pb and Cr. Therefore, further studies are urgently needed to investigate Pb and Cr immobilization mechanisms in soils during freeze-thaw cycles. Hence, these findings provided useful information on Pb and Cr immobilization process in soils that underwent freeze-thaw cycles to offer an additional insight into predicting Pb and Cr behaviors in cold and freezing environments.
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Zhang, Lei, Feipeng Ren, Hao Li, Dongbing Cheng, and Baoyang Sun. "The Influence Mechanism of Freeze-Thaw on Soil Erosion: A Review." Water 13, no. 8 (April 7, 2021): 1010. http://dx.doi.org/10.3390/w13081010.
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As an important type of soil erosion, freeze-thaw erosion occurs primarily at high latitude and altitude. The overview on the effect of freeze-thaw on soil erosion was provided. Soil erosion was affected by freeze-thaw processes, as thawing and water erosion reinforce each other. Remote sensing provided an unprecedented approach for characterizing the timing, magnitude, and patterns of large-scale freeze-thaw and soil erosion changes. Furthermore, the essence of soil freeze-thaw was the freeze and thaw of soil moisture in the pores of soil. Freeze-thaw action mainly increased soil erodibility and made it more vulnerable to erosion by destroying soil structure, changing soil water content, bulk density, shear strength and aggregate stability, etc. However, the type and magnitude of changes of soil properties have been related to soil texture, water content, experimental conditions and the degree of exposure to freeze-thaw. The use of indoor and field experiments to further reveal the effect of freeze-thaw on soil erosion would facilitate improved forecasting, as well as prevention of soil erosion during thawing in regions with freeze-thaw cycles.
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Li, Wenjun, Hanbing Liu, Bing Zhu, Xiang Lyu, Xin Gao, and Chunyu Liang. "Mechanical Properties and Freeze–Thaw Durability of Basalt Fiber Reactive Powder Concrete." Applied Sciences 10, no. 16 (August 16, 2020): 5682. http://dx.doi.org/10.3390/app10165682.
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Basalt fiber has a great advantage on the mechanical properties and durability of reactive powder concrete (RPC) because of its superior mechanical properties and chemical corrosion resistance. In this paper, basalt fiber was adopted to modified RPC, and plain reactive powder concrete (PRPC), basalt fiber reactive powder concrete (BFRPC) and steel fiber reactive powder concrete (SFRPC) were prepared. The mechanical properties and freeze–thaw durability of BFRPC with different basalt fiber contents were tested and compared with PRPC and SFRPC to investigate the effects of basalt fiber contents and fiber type on the mechanical properties and freeze–thaw durability of RPC. Besides, the mass loss rate and compressive strength loss rate of RPC under two freeze–thaw conditions (fresh-water freeze–thaw and chloride-salt freeze–thaw) were tested to evaluate the effects of freeze–thaw conditions on the freeze–thaw durability of RPC. The experiment results showed that the mechanical properties and freeze–thaw resistance of RPC increased as the basalt fiber content increase. Compared with the fresh-water freeze–thaw cycle, the damage of the chloride-salt freeze–thaw cycle on RPC was great. Based on the freeze–thaw experiment results, it was found that SFRPC was sensitive to the corrosion of chloride salts and compared with the steel fiber, the improvement of basalt fiber on the freeze–thaw resistance of RPC was great.
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Liu, Q., W. Chen, J. K. Guo, R. F. Li, D. Ke, Y. Wu, W. Tian, and X. Z. Li. "Fractional Stress Relaxation Model of Rock Freeze-Thaw Damage." Advances in Materials Science and Engineering 2021 (February 13, 2021): 1–8. http://dx.doi.org/10.1155/2021/3936968.
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Freeze-thaw cycle is a type of fatigue loading, and rock stress relaxation under freeze-thaw cycles takes into account the influence of the freeze-thaw cycle damage and deterioration. Rock stress relaxation under freeze-thaw cycles is one of the paramount issues in tunnel and slope stability research. To accurately describe the mechanical behaviour of stress relaxation of rocks under freeze-thaw, the software element is constructed based on the theory of fractional calculus to replace the ideal viscous element in the traditional element model. The freeze-thaw damage degradation of viscosity coefficient is considered. A new three-element model is established to better reflect the nonlinear stress relaxation behavior of rocks under freeze-thaw. The freeze-thaw and stress relaxation of rock are simulated by ABAQUS, the relevant model parameters are determined, and the stress relaxation equation of rock under freeze-thaw cycle is obtained based on numerical simulation results. The research shows that the test results are consistent with the calculated results, indicating that the constitutive equation can better describe the stress relaxation characteristics of rocks under freeze-thaw and provide theoretical basis for surrounding rock support in cold region.
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Zhou, Jie, Zeyao Li, and Wansheng Pei. "The Quantification and Evolution of Particle Characteristics of Saturated Silt under Freeze–Thaw Cycles." Applied Sciences 12, no. 21 (October 22, 2022): 10703. http://dx.doi.org/10.3390/app122110703.
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Freeze–thaw action is a complicated process. How it affects particle characteristics of saturated silt may provide a much clearer understanding of its internal mechanism. A series of specific apparatus were developed for sample reconstitution, including sand pluviation device, freeze–thaw device, and special sampling device. After reconstituting samples by sand pluviation method and a specific parameter-controlled freeze–thaw testing, scanning electron microscope (SEM) and laser scattering and transmissometry (LST) tests were conducted to explore the particle characteristics of silt under freeze–thaw cycles. The test results show that freeze–thaw action could probably induce the particles’ (60–200 μm) breakage, also affecting the clay particles’ (less than 5 μm) aggregation. With the increase of freeze–thaw times, freeze–thaw action on the particle impact decreases. The larger the effective confining pressure, the lower the freezing temperature, greater the compaction degree, and higher the fine content, which can all aggravate the effects of freeze–thaw action on silt particles. Finally, two characteristic evolution modes of particle structure under freeze–thaw cycles have been inferred based on particle interaction during the freeze–thaw process, which could provide a reference for long-term durability evaluation of pavements in cold regions.
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Niu, Jian Gang, Liang Yan, and Hai Tao Zhai. "Study on the Influence of Freeze-Thaw on the Carbonation Property of Fly Ash Concrete." Applied Mechanics and Materials 357-360 (August 2013): 939–43. http://dx.doi.org/10.4028/www.scientific.net/amm.357-360.939.
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Based on the coupling testing program of freeze-thaw and carbonation, the laboratory simulation test is carried out. The laws of carbonation depth of the fly ash concrete suffered the freeze-thaw cycle in different test modes and the influence of fly ash dosage on concrete carbonation depth after the freeze-thaw cycle are studied. Defining the influence coefficient of the freeze-thaw cycles on carbonation depth of concrete, the mechanism of coupling of freeze-thaw and carbonation is analyzed,and the role of freeze-thaw and carbonation in the coupling process are obtained.
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Mei, Song-hua, Xu-li Liang, Lei Wen, and Zi-long Kou. "Experimental Study on Mechanical Properties of Freeze-Thaw Damaged Red Sandstone under Combined Dynamic and Static Loading." Shock and Vibration 2021 (November 11, 2021): 1–14. http://dx.doi.org/10.1155/2021/9980549.
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Using the freeze-thaw cycle test chamber, the red sandstone samples are subjected to cyclic freeze-thaw tests. The physical properties, static mechanical properties of freeze-thaw damage rocks, and the compressional wave velocity at specific axial pressure are measured using conventional physical tests and uniaxial compression tests. The mechanical properties of freeze-thaw damage rocks under dynamic and static loading were studied using Hopkinson pressure bar which can exert axial pressure. The studies show that, with the increase of freeze-thaw cycles, the surface layer of the rock sample undergoes spalling phenomenon, the weight gradually decreases, the sample compactness becomes worse, there are microcracks between the cemented particles, and the compressive strength and elastic modulus decrease. Under the static loading, the longitudinal wave velocity of freeze-thaw damaged samples change significantly compared with that of samples without freeze-thaw. The freeze-thaw damage degree, axial pressure, and strain rate are coupled with each other, which together affect the dynamic mechanical properties of samples, and make the variation of mechanical parameters, such as dynamic peak strength and dynamic elastic modulus of rock. The combined action of freeze-thaw damage and axial pressure weakens the strain rate effect of samples, but when the incident wave of SHPB test is same, the dynamic strength and elastic modulus of freeze-thaw damaged samples are reduced compared with those without freeze-thaw. Combining with strain equivalence principle, the constitutive relation of freeze-thaw damage of red sandstone under dynamic and static combined loading can reflect the influence of coupling damage of axial pressure and freeze-thaw, dynamic impact parameters, and other factors, which are in good agreement with the test results.
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Wang, Qian, Fuqiang Liu, Xiumei Zhong, Zhongnan Gao, Shouyun Liang, and Yuxin Liang. "Dynamic Characteristics and Mechanism of the Saturated Compacted Loess under Freeze-Thaw Cycles." Geofluids 2021 (October 8, 2021): 1–12. http://dx.doi.org/10.1155/2021/6296578.
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To study the dynamic characteristics and mechanism of saturated loess after freeze-thaw cycles, a series of laboratory tests including freeze-thaw cycle tests, dynamic triaxial tests, and scanning electron microscope tests of the saturated remolded loess was conducted. The characteristics of the dynamic parameters of the saturated loess after different freeze-thaw cycles were discussed. The characteristics of the microstructure parameters changes were analyzed. The evolution process and mechanism of the microstructure of the remolded loess under freeze-thaw cycles were proposed. The results show that after different freeze-thaw cycles, the dynamic stress-dynamic strain curves of the saturated remolded loess conform to the hyperbolic model; however, the freeze-thaw cycle has a significant effect on the model parameter b . With the increase of freeze-thaw cycles, the dynamic shear modulus of saturated remolded loess first decreases and then increases, while the damping ratio is opposite. When saturated remolded loess experiences freeze-thaw cycles greater than four, its dynamic stability is better than that of saturated soil without freeze-thaw cycles. The dynamic stability reaches its peak after seven freeze-thaw cycles and is equivalent to that of saturated soil without freeze-thaw cycles after forty cycles. Combined with the results of the quantitative analysis of microstructure images, with the increase of the freeze-thaw cycles, the number of large and medium particles in the soil reduces, and the number of micros and small particles increases. The particle size tends to be uniform. The apparent porosity increases rapidly and then decreases sharply and tends to be stable after 4 freeze-thaw cycles. The pore and particle fractal dimensions continue to decrease. The probability of entropy increases first and then decreases. It is illustrated that the saturated loess has mainly experienced three steps under freeze-thaw cycles: (1) fracture and expansion of original skeleton cementation, (2) damage, crushing and aggregation of the particle, and (3) compaction and reorganization of soil structure. Besides, the saturation condition significantly accelerates the evolution process of the internal structure of the soil under freeze-thaw cycles. These lead to the strengthening effect of soil dynamic stiffness under long-term freeze-thaw cycles.
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Luo, Siqiong, Jingyuan Wang, John W. Pomeroy, and Shihua Lyu. "Freeze–Thaw Changes of Seasonally Frozen Ground on the Tibetan Plateau from 1960 to 2014." Journal of Climate 33, no. 21 (November 1, 2020): 9427–46. http://dx.doi.org/10.1175/jcli-d-19-0923.1.
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AbstractThe freeze–thaw changes of seasonally frozen ground (SFG) are an important indicator of climate change. Based on observed daily freeze depth of SFG from meteorological stations on the Tibetan Plateau (TP) from 1960 to 2014, the spatial–temporal characteristics and trends in SFG were analyzed, and the relationships between them and climatic and geographical factors were explored. Freeze–thaw changes of SFG on a regional scale were assessed by multiple regression functions. Results showed multiyear mean maximum freeze depth, freeze–thaw duration, freeze start date, and thaw end date that demonstrate obvious distribution characteristics of climatic zones. A decreasing trend in maximum freeze depth and freeze–thaw duration occurred on the TP from 1960 to 2014. The freeze start date has been later, and the thaw end date has been significantly earlier. The freeze–thaw changes of SFG significantly affected by soil hydrothermal conditions on the TP could be assessed by elevation and latitude or by air temperature and precipitation, due to their high correlations. The regional average of maximum freeze depth and freeze–thaw duration caused by climatic and geographical factors were larger than those averaged using meteorological station data because most stations are located at lower altitudes. Maximum freeze depth and freeze–thaw duration have decreased sharply since 2000 on the entire TP. Warming and wetting conditions of the soil resulted in a significant decrease in maximum freeze depth and freeze–thaw duration in the most area of the TP, while drying soil results in a slight increase of them in the southeast of the TP.
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Sun, Yazhen, Man Deng, Youlin Ye, Lin Gao, Huaizhi Zhang, and Zuoxin Ma. "Research of Method for Improving Antifreeze-Thaw Performance Based on Asphalt Mixture Freeze-Thaw Damage Development Process." Advances in Civil Engineering 2020 (August 27, 2020): 1–12. http://dx.doi.org/10.1155/2020/8879880.
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To improve the antifreeze-thaw performance of asphalt pavement in the seasonal freezing regions, the temperature and the time of freeze-thaw test were redesigned based on the climatic characteristics of the regions, and the splitting tensile strength tests were carried out to determine the low-temperature performance of the asphalt mixture under the influence of the gradation and the asphalt-aggregate ratio. A mathematical model was built to investigate the freeze-thaw damage law. According to the test results of splitting tensile strength of the asphalt mixture under freeze-thaw cycles, the probabilistic damage variable of the asphalt mixture was redefined and a physical probability model was built to analyse the freeze-thaw damage. Based on the freeze-thaw damage development process and the mechanism of the asphalt mixture, the effective measures to improve the antifreeze-thaw performance were provided and demonstrated through the correlations among the damage parameters (the shape parameter α, the scale factor λ, and the gradient factor ν) and the freeze-thaw resistance of the asphalt mixture. The test results showed that the splitting tensile strength decreased with the increase of the number of the freeze-thaw cycles. With the same gradation, the splitting freeze-thaw damage degree of the asphalt mixture with 5.8% asphalt-aggregate ratio is about 6% less than others after the 18th freeze-thaw cycle. The freeze-thaw resistance increases with the asphalt-aggregate ratio. With the same asphalt-aggregate ratio, the splitting freeze-thaw damage degree of S-grade mixtures is about 11.8% higher than that of Z-grade mixtures. S-grade mixtures have positive effects on the freeze-thaw resistance. The results suggest new measures for further investigation on the design and maintenance of the asphalt mixture in the seasonal freezing regions.
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Luo, San, Tianwen Bai, Mingqin Guo, Yi Wei, and Wenbo Ma. "Impact of Freeze–Thaw Cycles on the Long-Term Performance of Concrete Pavement and Related Improvement Measures: A Review." Materials 15, no. 13 (June 29, 2022): 4568. http://dx.doi.org/10.3390/ma15134568.
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Freeze–thaw damage is one of the most severe threats to the long-term performance of concrete pavement in cold regions. Currently, the freeze–thaw deterioration mechanism of concrete pavement has not been fully understood. This study summarizes the significant findings of concrete pavement freeze–thaw durability performance, identifies existing knowledge gaps, and proposes future research needs. The concrete material deterioration mechanism under freeze–thaw cycles is first critically reviewed. Current deterioration theories mainly include the hydrostatic pressure hypothesis, osmolarity, and salt crystallization pressure hypothesis. The critical saturation degree has been proposed to depict the influence of internal saturation on freeze–thaw damage development. Meanwhile, the influence of pore solution salinity on freeze–thaw damage level has not been widely investigated. Additionally, the deterioration mechanism of the typical D-cracking that occurs in concrete pavement has not been fully understood. Following this, we investigate the coupling effect between freeze–thaw and other loading or environmental factors. It is found that external loading can accelerate the development of freeze–thaw damage, and the acceleration becomes more evident under higher stress levels. Further, deicing salts can interact with concrete during freeze–thaw cycles, generating internal pores or leading to crystalline expansion pressure. Specifically, freeze–thaw development can be mitigated under relatively low ion concentration due to increased frozen points. The interactive mechanism between external loading, environmental ions, and freeze–thaw cycles has not been fully understood. Finally, the mitigation protocols to enhance frost resistance of concrete pavement are reviewed. Besides the widely used air-entraining process, the freeze–thaw durability of concrete can also be enhanced by using fiber reinforcement, pozzolanic materials, surface strengthening, Super Absorbent Polymers (SAPs), and Phase Change Materials. This study serves as a solid base of information to understand how to enhance the freeze–thaw durability of concrete pavement.
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Wang, Sheng-lin, Qing-feng Lv, Hassan Baaj, Xiao-yuan Li, and Yan-xu Zhao. "Volume change behaviour and microstructure of stabilized loess under cyclic freeze–thaw conditions." Canadian Journal of Civil Engineering 43, no. 10 (October 2016): 865–74. http://dx.doi.org/10.1139/cjce-2016-0052.
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Freeze–thaw action is considered to be one of the most destructive actions that can induce significant damage in stabilized subgrades in seasonally frozen loess areas. Laboratory tests including frost heave – thaw shrinkage and microstructure change during freeze–thaw cycles were conducted to evaluate the volume change rate of loess stabilized with cement, lime, and fly ash under the impact of cyclic freeze–thaw conditions. The loess specimens collapsed after eight freeze–thaw cycles (192 h), but most stabilized loess specimens had no visible damage after all freeze–thaw cycles were completed. All of the stabilized loess samples underwent a much smaller volume change than the loess alone after the freeze–thaw cycles. Although surface porosity and equivalent diameter of stabilized loess samples increased, the stabilized loess can retain its microstructure during freeze–thaw cycles when the cement content was less than 6%. To ensure freeze–thaw resistance of stabilized loess subgrades, the mix proportions of the three additives was recommended to be 4 to 5% cement, 6% lime, and 10% fly ash.
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Bi, Gui Quan. "Study on Influence of Freeze-Thaw Cycles on the Physical-Mechanical Properties of Loess." Advanced Materials Research 442 (January 2012): 286–90. http://dx.doi.org/10.4028/www.scientific.net/amr.442.286.
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Loess foundations in seasonally frozen soil region are subject to severe effect of freeze-thaw cycles. This often results in water redistribution and structure weakening. So it is very important to study the physical-mechanical properties of loess under freeze-thaw cycles. In this paper, systematic study was carried out using freeze-thaw cycle machine. The impacts of freeze-thaw cycles on the physical-mechanical properties of loess including deformation, water distribution and dry density under the condition of filling water to loess samples were investigated. The results proved that the freeze-thaw cycles can increase the water content gradually from the bottom to the top in the loess samples under water supplied condition. The water content gradient reaches maximum at the freeze-thaw interface. The loess samples deform sharply at the early stage of the freeze-thaw cycles and then reach a stable status. The freeze-thaw cycles decrease the dry density of the loess samples gradually. The dry density at the top is lower than that at the bottom, due to more severe freeze-thaw effect at the top of the samples.
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Zhu, Fangzhi, Zhiming Ma, and Tiejun Zhao. "Influence of Freeze-Thaw Damage on the Steel Corrosion and Bond-Slip Behavior in the Reinforced Concrete." Advances in Materials Science and Engineering 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/9710678.
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This paper mainly studies the behavior of steel corrosion in various reinforced concrete under freeze-thaw environment. The influence of thickness of concrete cover is also discussed. Additionally, the bond-slip behavior of the reinforced concrete after suffering the freeze-thaw damage and steel corrosion has also be presented. The results show that the freeze-thaw damage aggravates the steel corrosion in concrete, and the results become more obvious in the concrete after suffering serious freeze-thaw damage. Compared with the ordinary concrete, both air entrained concrete and waterproofing concrete possess better resistance to steel corrosion under the same freeze-thaw environment. Moreover, increasing the thicknesses of concrete cover is also an effective method of improving the resistance to steel corrosion. The bond-slip behavior of reinforced concrete with corroded steel decreases with the increase of freeze-thaw damage, especially for the concrete that suffered high freeze-thaw cycles. Moreover, there exists a good correlation between the parameters of bond-slip and freeze-thaw cycles. The steel corrosion and bond-slip behavior of reinforced concrete should be considered serious under freeze-thaw cycles environment, which significantly impact the durability and safety of concrete structure.
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Wang, Li Xue, Xiao Ting Shan, Yu Qing Zhang, Chun Sheng Li, Zai Xing Wang, and Xiu Hong Wang. "Experimental Study of Compression and Carbonation in Concrete Subjected to Freeze-Thaw Environment." Advanced Materials Research 887-888 (February 2014): 814–18. http://dx.doi.org/10.4028/www.scientific.net/amr.887-888.814.
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In order to research the changes of concrete properties in freeze-thaw environment, five concrete samples with water-cement ratio respectively equal to 0.60, 0.65, 0.70, 0.75 and 0.80 were tested in freeze-thaw environment according to GB/T50082-2009 concrete rapid freeze-thaw cycles test method. Five samples were carried out 0, 25, 50, 75, 100 times faster freeze-thaw cycles test. With the increasing number of freeze-thaw cycles, the concrete relative dynamic modulus of elasticity loss rises, the compressive strength drops, and the carbonation depth increases. The greater the water-cement ratio of concrete specimens with freeze-thaw cycles, the greater the degree of damage increases.
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Zhang, Shiyi, Yingfang Fan, and Surendra P. Shah. "Study on Deformation Characteristics and Damage Model of NMK Concrete under Cold Environment." Buildings 12, no. 9 (September 12, 2022): 1431. http://dx.doi.org/10.3390/buildings12091431.
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To improve the ability of concrete structures to resist freeze-thaw damage in cold environments, explore the effect and mechanism of nano-metakaolin (NMK) on frost resistance of concrete. And make up for the deficiencies in the mechanical properties and deformation process of na-no-metakaolin concrete in freeze-thaw environments. Rapid freeze-thaw cycle experiment was car-ried out to detect the deterioration law of concrete. Physical and mechanical properties under freeze-thaw environment was measured. The modification mechanism of nano-metakaolin on con-crete frost resistance from micro and meso scales was analyzed. The effect of freeze-thaw damage on nano-metakaolin concrete was characterized. The influence law of stress strain is established, and the meso-statistical damage constitutive model of nano-metakaolin concrete under freeze-thaw action is established. The results show that: Compared with other nano-clays, adding 5% nano-metakaolin can effectively slow down concrete’s freeze-thaw cracking and crack propagation. After 125 freeze-thaw cycles, the surface crack width of concrete mixed with 5% nano-metakaolin is only 0.1mm. Without freeze-thaw cycles, the compressive strength of concrete mixed with 3% nano-metakaolin is the highest, which is 28.75% higher than that of ordinary concrete; after 125 freeze-thaw cycles, the loss rate of compressive strength of concrete mixed with 5% nano-metakaolin was 12.07%. After 125 freeze-thaw cycles, the peak strain is 0.45 times that of concrete without NMK, and the peak stress is 3 times that of concrete without NMK.
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Jia, Peng, Songze Mao, Yijin Qian, Qiwei Wang, and Jialiang Lu. "The Dynamic Compressive Properties and Energy Dissipation Law of Sandstone Subjected to Freeze–Thaw Damage." Water 14, no. 22 (November 11, 2022): 3632. http://dx.doi.org/10.3390/w14223632.
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To investigate the dynamic compressive properties and the law of energy dissipation of freeze–thaw-damaged sandstone, static and dynamic compressive experiments were conducted. The influences of the number of freeze–thaw cycles and strain rate on strength characteristics, energy dissipation rate and the fractal dimension characteristics of sandstone were evaluated. Based on the peak energy dissipation rate, a freeze–thaw damage variable was established. The results show that peak strength increases exponentially with strain rate, and there exists a strain rate threshold. When strain rate is below this threshold, the increasing rate of the DIF slows down with the increase in the number of freeze–thaw cycles; when strain rate is higher than this threshold, the increasing rate of the DIF increases with the increase in the number of freeze–thaw cycles. In addition, the fractal dimension increases with the number of freeze–thaw cycles as well as the strain rate. Based on the freeze–thaw damage variable established, the damage degree of sandstone under freeze–thaw cycling can be characterized.
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Yu, Zhijie, Jianhong Fang, Anhua Xu, and Wenjun Zhou. "The Study of Influence of Freeze-Thaw Cycles on Silty Sand in Seasonally Frozen Soil Regions." Geofluids 2022 (April 7, 2022): 1–12. http://dx.doi.org/10.1155/2022/6886108.
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Freeze-thaw cycles can cause varying degrees of damage to expressway, in order to study the influence of freeze-thaw cycles on silty sand of expressway in Qinghai seasonal frozen soil regions, triaxial compression tests were carried out on silty sand under different initial freeze-thaw temperatures and freeze-thaw cycles. The stress-strain curve, secant modulus, cohesion, internal friction angle, dynamic shear modulus, and dynamic damping ratio of soil after freeze-thaw cycles were analyzed and studied. The experimental results show that the number of freeze-thaw cycles has different effects on the stress-strain curves at different initial freezing temperatures. With the increase of freeze-thaw cycles, the secant modulus of soil increases and changes in wave shape. The cohesion decreases and the internal friction angle decreases nonlinearly. The dynamic shear modulus and damping ratio do not change significantly. The change of freeze-thaw cycles will also affect the physical structure of the soil itself. The change of freeze-thaw cycles will also affect the physical structure of the soil itself. It will change the mosaic form of soil particles, the shape of soil particles, the size of soil particles and pores, and also make the redistribution of water in the soil.
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Ke, Bo, Keping Zhou, Hongwei Deng, and Feng Bin. "NMR Pore Structure and Dynamic Characteristics of Sandstone Caused by Ambient Freeze-Thaw Action." Shock and Vibration 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/9728630.
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For a deeper understanding of the freeze-thaw weathering effects on the microstructure evolution and deterioration of dynamic mechanical properties of rock, the present paper conducted the nuclear magnetic resonance (NMR) tests and impact loading experiments on sandstone under different freeze-thaw cycles. The results of NMR test show that, with the increase of freeze-thaw cycles, the pores expand and pores size tends to be uniform. The experimental results show that the stress-strain curves all go through four stages, namely, densification, elasticity, yielding, and failure. The densification curve is shorter, and the slope of elasticity curve decreases as the freeze-thaw cycles increase. With increasing freeze-thaw cycles, the dynamic peak stress decreases and energy absorption of sandstone increases. The dynamic failure form is an axial splitting failure, and the fragments increase and the size diminishes with increasing freeze-thaw cycles. The higher the porosity is, the more severe the degradation of dynamic characteristics is. An increase model for the relationships between the porosity or energy absorption and freeze-thaw cycles number was built to reveal the increasing trend with the freeze-thaw cycles increase; meanwhile, a decay model was built to predict the dynamic compressive strength degradation of rock after repeated freeze-thaw cycles.
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Mao, Mingjie, Dongsheng Zhang, Qiuning Yang, and Wenbo Zhang. "Study of Durability of Concrete with Fly Ash as Fine Aggregate under Alternative Interactions of Freeze-Thaw and Carbonation." Advances in Civil Engineering 2019 (April 16, 2019): 1–15. http://dx.doi.org/10.1155/2019/4693893.
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To study the durability of concrete with fly ash as fine aggregate subjected to alternative attacks of freeze-thaw and carbonation, the appearance, mass loss, relative dynamic modulus of elasticity, relative compressive strength, and carbonation depth of the concrete are investigated using cyclic tests under single carbonation, single freeze-thaw, and alternation of freeze-thaw and carbonation. In addition, microstructural analysis techniques including scanning electron microscope and X-ray diffraction are adopted to reveal the deterioration mechanism of alternating freeze-thaw and carbonation. Results show that carbonation is beneficial for refining the pore structure and increasing concrete strength in the initial alternative cycle, which delays the damage from freeze-thaw cycles. Damage from freeze-thaw causes crack propagation in concrete, which leads to carbonation intensification. Compared with other test modes, concrete under alternative freeze-thaw and carbonation causes the greatest degree of deterioration during the initial freeze-thaw cycles. The carbonation depth under alternative freeze-thaw and carbonation is positively correlated with the carbonation time and the water-to-cement ratio. However, as the reactant is continuously consumed due to the expansion of crystalline ice and CaCO3, alternative cycles result in the appearance of many more new cracks in the concrete.
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Cao, Da Fu, Kai Fu Zhou, Min Zhou, Wen Jie Ge, and Bi Yuan Wang. "Study on the Shear Behaviors of RC Beams after Freeze-Thaw Cycles." Applied Mechanics and Materials 488-489 (January 2014): 750–54. http://dx.doi.org/10.4028/www.scientific.net/amm.488-489.750.
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In order to investigate the shear behaviors of RC beams after freeze-thaw cycles, static shear experiments of 45 RC beams after 0, 75, 100, 125, and 150 freeze-thaw cycles were made. The influences of different numbers of freeze-thaw cycles on the shear behaviors of RC beams with different stirrup spacing were studied. The results show that Freeze-thaw cycle, stirrup spacing of reinforced concrete beam has no significant effect on crack distribution and failure pattern; cracking load and ultimate load of shear beams decrease with the increasing of freeze-thaw cycles.
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Örmeci, B., and P. A. Vesilind. "Effect of extracellular polymers on freeze-thaw conditioning of activated sludge." Water Science and Technology 46, no. 10 (November 1, 2002): 269–79. http://dx.doi.org/10.2166/wst.2002.0351.
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In this study, the effects of extracellular polymers on freeze-thaw conditioning of activated sludge are investigated. Various physical and chemical extraction methods including centrifugation, blending, heat, EDTA, EGTA, and NaOH extraction were used to remove extracellular material from sludge matrix. The improvements in freeze-thaw conditioning were evaluated by commonly used measures of sludge dewaterability. The results of this study indicate that removal of extracellular polymers using relatively gentle extraction methods before freeze-thaw conditioning improves the sludge dewaterability after the freeze-thaw. In addition to extracellular polymers, cations also play an important role in determining the freeze-thaw effectiveness on activated sludge. Best dewaterability is achieved when both extracellular polymers and cations are removed from activated sludge before freeze-thaw conditioning.
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Tang, Xie Xing, Xiao Yong Luo, Qi Sun, and Ya Chuan Kuang. "Test Research on Mechanical Property of GFRP Bolt under Freeze-Thaw Cycle Conditions." Key Engineering Materials 531-532 (December 2012): 689–94. http://dx.doi.org/10.4028/www.scientific.net/kem.531-532.689.
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In this paper, GFRP bolts in diameter of 25mm are tested through freeze-thaw cycle by 50, 100 and 150 times to study their change law of appearance, weight, strength and elastic modulus. As reflected from the test results, after the freeze-thaw cycle, the appearance and weight of GFRP bolts are basically not changed. As the freeze-thaw cycle increases from 50 times to 100 times, the strength of bolts decreases gradually. After 50, 100 and 150 times of freeze-thaw cycle, the ultimate tensile strength of bolt decreases by 2.82%, 4.35% and 8.84%, respectively. During the process that the times of freeze-thaw cycle increase from 50 to 100, the elastic modulus of GFRP bolts grows gradually. After 50, 100 and 150 times of freeze-thaw cycle, the elastic modulus increases by 1.42%, 2.68% and 3.92%, respectively. The freeze-thaw cycle leads to embrittlement of GFRP materials and weakness of ductility, while not obviously.
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Chen, Zongfang, Huie Chen, Jinfeng Li, Hui Li, and Wenliang Ma. "Study on the Changing Rules of Silty Clay’s Pore Structure under Freeze-Thaw Cycles." Advances in Civil Engineering 2019 (April 1, 2019): 1–11. http://dx.doi.org/10.1155/2019/7493872.
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For engineering construction in seasonally frozen regions, when the soil below the frost depth without freeze-thaw effect was exposed or reclaimed after excavation, long-term freeze-thaw will change soil skeleton and porous characteristics, thereby leading to the deterioration of soil engineering properties. This study focused on seasonally frozen silty clay from Changchun, China, and conducted different freeze-thaw cyclic tests on remoulded soil samples, during which both freezing temperature and the number of freeze-thaw cycles were varied. The related data of pore structures under different test conditions were acquired through mercury injection porosimetry (MIP) tests, and the effects of the number of freeze-thaw cycles and freezing temperature on the change of the soil’s pore structure were investigated in detail in combination with fractal theory. The variation rules of pores in the soil after freeze-thaw cycles were investigated from a microperspective so as to essentially analyze the mechanism of the deteriorating effect of freeze-thaw on a soil’s engineering properties.
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Zhang, Hui Mei, and Geng She Yang. "Damage Model and Damage Mechanical Characteristics of Loaded Rock under Freeze-Thaw Conditions." Advanced Materials Research 168-170 (December 2010): 658–62. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.658.
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Considering the heterogeneous characteristics of rock at mesoscopic level, the damage propagation constitutive relation and evolution equation of freeze-thaw and loaded rock were established by using the theory of macro phenomenological damage mechanics and the generalized theory of strain equality. The evolutionary mechanisms of micro-structural damage and materials mechanical properties for the loaded rock were discussed under freeze-thaw condition, verified by experimental results of the freeze-thaw cycle and compression test of rock. It is shown that the freeze-thaw and loaded damage model can represent the complicated relations among the freeze-thaw, load and the damage inside the rock, reveal the coupling failure mechanism of macroscopic rock under the freeze-thaw and load from the micro-damage evolution. The combined effect of freeze-thaw and load exacerbates the total damage of rock with obvious nonlinear properties, but the coupling effect weakens the total damage. The lithology and initial damage state of the freeze-thaw and loaded rock in engineering structures in cold regions determine the weights of influence factors to mechanical properties, including environmental factor, loading factor and the coupling effects, so the rock performances different damage mechanical characteristic.
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Liu, Gui Feng, Zheng Fa Chen, and Xue Xing Chen. "The Mechanics Performance of C30 Concrete with Manufactured-Sand under Condition of Freeze-Thaw Cycles." Applied Mechanics and Materials 71-78 (July 2011): 1036–39. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.1036.
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Although many people discussed the strength and durability of concrete with natural sand in severe environment, few people investigated the mechanics performance of concrete with manufactured-sand under condition of freeze-thaw cycle, at present. Experimental studies on C30 concrete with manufactured-sand were carried out under condition of freeze-thaw cycle, which based on the testing of raw material performance and concrete mix ration, in this paper. Comparative studies on the changing laws of the mass, strength and the relative dynamic elastic modulus of concrete were developed in three cases which were freeze-thaw cycle, freeze-thaw cycle and acid corrosion and freeze-thaw cycle and alkali corrosion. The test results showed that the mass, strength and the relative dynamic elastic modulus of concrete with manufactured-sand decreased evidently with the increasing of times of freeze-thaw cycle. The durability of acid and alkali-resistant of concrete with manufactured-sand was also remarkably weakened due to the action of freeze-thaw cycle. The capability of acid and alkali-resistant of the concrete was decreased with the increasing of times of freeze-thaw cycle and the anti-acid capability was decreased more seriously.
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Li, Jielin, Rennie B. Kaunda, Longyin Zhu, Keping Zhou, and Feng Gao. "Experimental Study of the Pore Structure Deterioration of Sandstones under Freeze-Thaw Cycles and Chemical Erosion." Advances in Civil Engineering 2019 (January 16, 2019): 1–12. http://dx.doi.org/10.1155/2019/9687843.
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The issue of rock deterioration in chemical environments has drawn much attention in recent years in the rock engineering community. In this study, a series of 30 freeze-thaw cycling tests are conducted on sandstone samples soaked in H2SO4 solution and in pure water, prior to the application of nuclear magnetic resonance (NMR) on the rock specimens. The porosity of the sandstone, the distribution of transverse relaxation time T2, and the NMR images are acquired after each freeze-thaw cycle. The pore size distribution curves of the sandstone after freeze-thaw cycles, four categories of pore scale, and the features of freeze-thaw deterioration for pores of different sizes in H2SO4 solution and pure water are established. The result shows that, with the influence of the acid environment and the freeze-thaw cycles, the mass of the samples largely deteriorates. As the freeze-thaw cycles increase, the porosity of rocks increases approximately linearly. The distribution of the NMR T2 develops gradually from 4 peaks to 5 or even to 6. Magnetic resonance imaging (MRI) dynamically displays the process of the freeze-thaw deterioration of the microstructure inside the sandstones under acid conditions. The results also show pore expansion in rocks under the coupling effects of chemistry and the freeze-thaw cycles, which differ largely from the freeze-thaw deterioration of the rock specimens placed in pure water.
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Xiao, Yigai, Hongwei Deng, Guanglin Tian, and Songtao Yu. "Analysis of Microscopic Pore Characteristics and Macroscopic Energy Evolution of Rock Materials under Freeze-Thaw Cycle Conditions." Mathematics 11, no. 3 (January 31, 2023): 710. http://dx.doi.org/10.3390/math11030710.
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The repeated cyclic freeze-thaw effect in low-temperature environments causes irreversible damage and deterioration to the microscopic pore structure and macroscopic mechanical properties of a rock. To study the effects of the freeze-thaw cycle on the porosity and mechanical properties, the indoor freeze-thaw cycle test and mechanical tests of sandstone-like materials were conducted. Based on nuclear magnetic resonance, the influence of the freeze-thaw cycle on microscopic pores was analyzed, and the intrinsic relationship between porosity and mechanical strength was discussed. Meanwhile, the energy change in the uniaxial compression test was recorded using the discrete element software (PFC2D). The influence of freeze-thaw cycles on different types of energy was analyzed, and the internal relationship between different energies and freeze-thaw cycles was discussed. The results showed that the microscopic pore structure is dominated by micropores, followed by mesopores and the smallest macropores. With an increase in the freeze-thaw cycle, both micropores and mesopores showed an increasing trend. The porosity showed an exponentially increasing trend with the increase in freeze-thaw cycles. The peak strength and elastic modulus decreased exponentially with the increase in freeze-thaw times, while the peak strain showed an exponentially increasing trend. The strain energy and bond strain energy showed a trend of increasing and decreasing in the front and back stages of the peak strength, respectively. However, the frictional energy always showed an increasing trend. The total energy, strain energy, bond strain energy, and friction energy all showed exponential increases with the increase in the number of freeze-thaw cycles.
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Stepanova, V. F., G. V. Chehniy, I. M. Parshina, S. A. Orekhov, and A. I. Kruglov. "Study into the freeze-thaw/ frost-salt resistance of high-strength B60–B100 concrete." Bulletin of Science and Research Center of Construction 33, no. 2 (April 19, 2022): 183–93. http://dx.doi.org/10.37538/2224-9494-2022-2(33)-183-193.
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Introduction. The development of the Arctic Region and oil and gas fields in the North Atlantic Ocean leads to an increase in the production of high-strength concrete structures. Thus, it is becoming increasingly vital to make such low-permeability concretes more freeze-thaw resistant.Aim. To conduct experimental studies for obtaining reliable data required to develop a standardized approach to the normalization of freeze-thaw / frost-salt resistance parameters characterizing high-strength concretes.Materials and methods. The study was performed using concretes of eight compositions (B60–B100 compressive strength grades). The freeze-thaw/frost-salt resistance of high-strength concretes was determined using the third rapid method involving the saturation, freezing, and thawing of samples in a 5 % sodium chloride solution, as well as assessment of freeze-thaw resistance in terms of strength, mass variation, and the dynamic modulus of elasticity. A variety of methods for increasing the water saturation of highstrength concrete were examined in order to expedite the testing process of high-strength concrete for freeze-thaw resistance.Results. The studies into the freeze-thaw/frost-salt resistance of high-strength B60-B100 concretes revealed their high freeze-thaw resistance. Following 37 freeze-thaw cycles, the lower confidence limit for the strength of test samples was higher than that of control samples multiplied by a coefficient of 0.9. The frost-resistance grade of these concretes is above F2 300. No critical decrease in the dynamic modulus of elasticity is observed, which indicates a significant freeze-thaw/frost-salt resistance of all tested highstrength concrete compositions.Conclusions. The freeze-thaw resistance studies of high-strength concretes carried out at NIIZHB named after A.A. Gvozdev yielded experimental data required to subsequently develop a standardized approach to the normalization of freeze-thaw/frost-salt resistance parameters characterizing high-strength concretes.
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Cao, Haibo, Tuanjie Chen, Hongzhou Zhu, and Haisheng Ren. "Influence of Frequent Freeze–Thaw Cycles on Performance of Asphalt Pavement in High-Cold and High-Altitude Areas." Coatings 12, no. 6 (May 31, 2022): 752. http://dx.doi.org/10.3390/coatings12060752.
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This study explores the temperature changes and freeze–thaw cycles in certain typical high-altitude areas, finding that these areas encounter more than 120, or even more than 200, freeze–thaw cycles per year. Such frequent freeze–thaw cycles deliver significant impact on the performance of asphalt pavements, with cracks becoming a typical problem in high-altitude areas. Such factors as cold weather, large temperature differences, and frequent freeze–thaw cycles have adverse effects on the stress of asphalt pavement materials, resulting in cracks in pavements. By simulating the conditions of such frequent freeze–thaw cycles, this study explores the law of changes in the performance of roads made from asphalt and asphalt mixtures, as well as the low-temperature crack resistance properties of asphalt and asphalt mixtures in frequent freeze–thaw cycles. It is found that the performance of the three different types of asphalt binders used in the test shows basically no change after 50 freeze–thaw cycles, and the asphalt types have a significant effect on the low-temperature performance of asphalt mixtures. The modified asphalt shows a higher viscosity than the matrix asphalt, with better toughness than that of the matrix asphalt at low temperature. Frequent freeze–thaw cycles significantly influence the low-temperature splitting tensile strength and water stability of asphalt mixtures; with increased freeze–thaw cycles, the splitting strength and freeze–thaw splitting tensile strength ratio will gradually decrease to a significant level. The freeze–thaw conditions are found delivering remarkable influence on the low-temperature splitting tensile strength and water stability of asphalt mixtures. The research results of this study provide a basis for the selection of asphalt pavement materials as well as the optimal design of mixtures in high-altitude area like the Qinghai-Tibet Plateau.
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Gao, Zhongnan, Xiumei Zhong, HaiPing Ma, Fuqiang Liu, Jinlian Ma, and Qian Wang. "Effect of Freeze-Thaw Cycles on Shear Strength Properties of Loess Reinforced with Lignin Fiber." Geofluids 2022 (May 3, 2022): 1–19. http://dx.doi.org/10.1155/2022/8685553.
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Freeze-thaw cycles caused by climate change can change the structure and strength of the soil. In seasonally frozen soil areas, the use of improved loess as a filling material must consider the effects of freeze-thaw cycles. With the increasingly severe global environmental problems, the search for suitable new environmental protection improvement materials has become one of the hotspots in soil performance improvement research. The purpose of this paper is to use lignin fiber to improve the engineering performance and freeze-thaw resistance of loess and to reduce the negative impact of engineering construction on the environment of the loess area. Based on a series of triaxial shear tests, the effects of freeze-thaw cycles on the stress-strain relationship, shear strength, and Mohr-Coulomb’s strength parameters of loess reinforced with lignin fiber were analyzed. Combined with the volume change and microstructure characteristics of fiber-reinforced loess before and after the freeze-thaw cycles, the reasons for the effects of the freeze-thaw cycles on the shear strength characteristics of fiber-reinforced loess are discussed. The research results showed that after 15 freeze-thaw cycles, the shear strength of loess reinforced with 1% fiber increased by 0.15%, 2.05%, and 1.35% at 80, 140, and 200 kPa, respectively. The shear strength of the reinforced loess with other fiber contents decreases to different degrees, and the maximum reduction ratio can reach 9.54%. Freeze-thaw cycles changed the variation of shear strength and strength parameters with fiber content. When the fiber content is less than 1%, the shear strength, cohesion, and friction angle of fiber-reinforced loess increase the fastest after freeze-thaw cycles. When the fiber content is 1%, the overall destruction effect of freeze-thaw cycles on fiber-reinforced loess is inhibited, and the soil has the best freeze-thaw resistance.
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Chen, Yu, Rong Gui Liu, Wei Ling Zhou, Yi Duo Zhang, Tao Liu, Huan Li, Shao Feng Zhang, and Chun Hua Lu. "Reliability Analysis of PC Structure in Chloride Corrosion Subjoining Cyclic Freeze-Thaw." Advanced Materials Research 163-167 (December 2010): 3301–5. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.3301.
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Based on chloride diffusion and random field theory, an analytical model of PC structures in erosive environment with chloride corrosion subjoining cyclic freeze-thaw was formulated. Models presenting the influence of chloride and cyclic freeze-thaw to failure probability are used to track the structural failure. It is found that cyclic freeze-thaw could be the driving force to damage of concrete in rigidity and mechanics. The computing results show that reliability index increases with the cover thickness, and cyclic freeze-thaw increases with decrease reliability. It is important to reliability calculation whether considering cyclic freeze-thaw.
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Yang, Xiaolin, Genhui Wang, Shiwu Gao, Min Song, and Anqi Wang. "Equation for the Degradation of Uniaxial Compression Stress of Concrete due to Freeze-Thaw Damage." Advances in Materials Science and Engineering 2019 (December 18, 2019): 1–8. http://dx.doi.org/10.1155/2019/8603065.
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To study the freeze-thaw damage characteristics of concrete, the uniaxial compressive tests of concrete under different number of freeze-thaw cycles were conducted, and the damage variable of freeze-thaw was obtained. The test results showed that the stress was a function of strain and freeze-thaw damage variable, and it can describe the degradation of concrete strength. Meanwhile, the equation for the stress-strain curved surface about strain and freeze-thaw damage variable was also proposed in this paper. The derivative function of the stress-strain curved surface equation with respect to strain presented the change of elastic modulus with the increase of freeze-thaw cycle number. Equation proposed in this paper can be used for predicting the concrete lifetime effectively in cold and large temperature difference regions.
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Fan, Cai Xia, and Hao Tian. "Advances in Damage of Concrete due to Freeze-Thaw Circles." Applied Mechanics and Materials 507 (January 2014): 204–8. http://dx.doi.org/10.4028/www.scientific.net/amm.507.204.
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Mechanism for damage of concrete due to freeze-thaw circles was summarized. The freeze-thaw model of concrete was discussed and analyzed. The developing directions about the freeze-thaw of concrete were recommended.
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Mangat, Sunny, Ray Bilevicius, Duane Griffin, Kelly Kjartanson, and Paul Wobma. "Freeze Thaw Pond Design." Proceedings of the Water Environment Federation 2008, no. 3 (January 1, 2008): 765–73. http://dx.doi.org/10.2175/193864708788806755.
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Parker, Philip J., Anthony G. Collins, and James R. DeWolfe. "Freeze-thaw residuals conditioning." Journal - American Water Works Association 92, no. 4 (April 2000): 168–81. http://dx.doi.org/10.1002/j.1551-8833.2000.tb08931.x.
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Xiang, Junzheng, Hengrui Liu, Hao Lu, and Faliang Gui. "Degradation Mechanism and Numerical Simulation of Pervious Concrete under Salt Freezing-Thawing Cycle." Materials 15, no. 9 (April 22, 2022): 3054. http://dx.doi.org/10.3390/ma15093054.
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In order to explore the occurrence area of pervious concrete freeze-thaw deterioration, the mass loss, strength deterioration, ultrasonic longitudinal wave velocity and dynamic elastic modulus attenuation of pervious concrete under freeze-thaw cycles were measured, and a prediction model of freeze-thaw damage was established. The mechanical properties of hardened cement pastes with the same W/C ratio under freeze-thaw cycles were also measured. Mercury intrusion porosimetry (MIP) was used to measure the pore structure characteristic parameters and pore size distribution changes of cement paste under freeze-thaw cycle, and the microstructure evolution of interfacial transition zone (ITZ) of paste and aggregate was observed by SEM scanning electron microscopy. Finally, a pervious concrete model was established by DEM to analyze the relationship between the number of freeze-thaw cycles and the mesoscopic parameters. The results indicated that the quality, strength and dynamic elastic modulus of pervious concrete deteriorate to different degrees under the conditions of water freezing and salt freezing. The damage sensitivity and strength loss of freeze-thaw damage is greater than the dynamic elastic modulus loss, which is greater than mass loss. In the pervious concrete paste which underwent 100 freeze-thaw cycles, the pore structure and macro strength had no obvious change, and hardened paste and the aggregate-interface-generated defects increased with the increase in freezing and thawing times, indicating that the deterioration of pervious concrete performance under freeze-thaw cycles was closely related to the deterioration of the interface strength of the aggregate and hardened paste. The pervious concrete model established by DEM can accurately simulate the change of the compressive modulus and the strength of pervious concrete during freeze-thaw cycles.
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Shi, Lei, Yang Liu, Xiangzhen Meng, and Huimei Zhang. "Study on Mechanical Properties and Damage Characteristics of Red Sandstone under Freeze-thaw and Load." Advances in Civil Engineering 2021 (June 17, 2021): 1–13. http://dx.doi.org/10.1155/2021/8867489.
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To analyze the effects of freeze-thaw cycles and confining pressure on the mechanical properties of red sandstone, through freeze-thaw cycles and triaxial compression tests, full stress-strain curves of different freeze-thaw cycles and different confining pressures were obtained. The degradation degree of red sandstone was quantitatively considered from different mechanical parameters of ultimate stress, elastic modulus, and Poisson’s ratio. Based on summarizing the characteristics of rock under freeze-thaw and load, the total damage variable of rock was determined by the reasonable measurement of freeze-thaw damage variable and load damage variable, and a damage constitutive model under freeze-thaw and load was established. The research showed that the freeze-thaw cycles aggravate the degree of rock damage deterioration, the rock stiffness and strength were reduced, and the characteristics of plastic deformation and ductile failure were more obvious. The confining pressure inhibited red sandstone internal damage, and with the increase of confining pressure, the stiffness and strength and the plastic characteristics were increased. In the overall trend, the mechanical parameters had different sensitivity to the degradation effect of freeze-thaw cycles and confining pressure. Regardless of the increase in the number of freeze-thaw cycles or confining pressure, the strain softening modulus tended to decrease gradually, and red sandstone plastic damage became more obvious after the stress peak. The total damage evolution path of red sandstone reflected the nonlinear influence of freeze-thaw and load on the total damage propagation. The research results provide theoretical support for the improvement of the technology of the effluent coal rock in Balasu Coal Mine.
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Chen, Bin, and Jun Wang. "Experimental Study on the Durability of Alkali-Activated Slag Concrete after Freeze-Thaw Cycle." Advances in Materials Science and Engineering 2021 (July 10, 2021): 1–19. http://dx.doi.org/10.1155/2021/9915639.
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A freeze-thaw resistance is an important indicator of the durability of alkali-activated slag concrete, which causes structural failure when the performance is low, especially in severely cold areas. In this study, solid sodium aluminate and sodium silicate were used as composite alkaline activators, while slag was used as the raw material to prepare alkali-activated slag concrete, whose freeze-thaw resistance, as well as that of ordinary cement concrete, was experimentally studied by varying the freeze-thaw cycles. The effects of the mass, compressive strength, and dynamic elastic modulus of the sample were investigated by considering the influence of different water-to-slag ratios and slag contents, while the damage variables and model were also analyzed. The results showed that alkali-activated slag concrete had an excellent freeze-thaw resistance, which was significantly affected by the water-to-slag ratio and compressive strength; specifically, the higher the water-to-slag ratio, the lower the freeze-thaw resistance, and the higher the compressive strength, the better the freeze-thaw resistance. The freeze-thaw durability, microstructure, and damage mechanism were studied via microscopic analysis. When analyzed via the microstructure test, crack pores and microcracks with narrow spaces and large surface areas were generated under freeze-thaw damage conditions, but the dense hydration structure and high-bonding-strength hydration products led to a better freeze-thaw resistance. The damage model was established using compressive strength and relative dynamic elastic modulus as damage variables, and the attenuation exponential and accumulative damage power function model had a high accuracy, which could better reflect the freeze-thaw damage law and damage degree and predict the lifetime of alkali-activated slag concrete.
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Cui, Lizhuang, Nan Qin, Shuai Wang, and Xuezhi Feng. "Experimental Study on the Mechanical Properties of Sandstone under the Action of Chemical Erosion and Freeze-Thaw Cycles." Advances in Civil Engineering 2021 (March 1, 2021): 1–14. http://dx.doi.org/10.1155/2021/8884079.
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In order to study the mechanical properties of sandstone under the coupling action of chemical erosion and freeze-thaw cycles, the fine-grained yellow sandstone in a mining area in Zigong, China, is collected as the research object. The changes in mechanical properties of yellow sandstone under the coupling action of chemical solution erosion and freeze-thaw cycles are analyzed based on uniaxial compression tests (UCTs) and triaxial compression tests (TCTs). The results show that, with the increase in freeze-thaw cycles, the compressive strength, elastic modulus, and cohesion of the sandstone samples decrease with varying degrees. Under constant freeze-thaw cycles, the most serious mechanical properties of degradation are observed in acidic solution, followed by alkaline solution and neutral solution. Under different confining pressures, the compressive strength and elastic modulus of the sandstone samples decrease exponentially with the increase in freeze-thaw cycles. Under the action of the chemical solution erosion and freeze-thaw cycles, the internal friction angle fluctuates around 30°. For the cohesion degradation, 35.4%, 29.3%, and 27.2% degradation are observed under acidic, alkaline, and neutral solutions. Nuclear magnetic resonance imaging shows that the chemical erosion and freeze-thaw cycles both promote the degradation of rock properties from surface to interior; after 45 freeze-thaw cycles, the mechanical properties drop sharply. To properly design rock tunneling support and long-term protection in the cold region, the impact of both freeze-thaw cycles and chemical erosion should be considered.
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Huang, Man, Bin Tang, Jianliang Jiang, Renqiu Guan, and Huajun Wang. "Experimental Study on Freeze-Thaw Cycle Duration of Saturated Tuff." Advances in Civil Engineering 2020 (July 24, 2020): 1–10. http://dx.doi.org/10.1155/2020/8813610.
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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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Mao, Ji Ze, Hong Ye Wang, Zhi Yuan Zhang, and Zong Min Liu. "Finite Element Analysis for Concrete Damage under Freeze-Thaw Action." Key Engineering Materials 417-418 (October 2009): 133–36. http://dx.doi.org/10.4028/www.scientific.net/kem.417-418.133.
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Freeze-thaw damage is one of the most representative damages in concrete durability. Commonly, freezing and thawing tests are conducted to investigate the freeze-thaw resistance of concrete, and the loss of dynamic modulus of concrete is regarded as the failure criterion. However, the research on the evolution of concrete strength during the damage process is still not enough when subjected to freezing and thawing. In this study, the concrete freeze-thaw deterioration was considered as isotropic elastic damage, and relative variation functions of dynamic modulus and Poisson’s ratio with freeze-thaw cycles were set up. Based on damage mechanics, the Ottosen failure surface model with four parameters was established to indicate the relationship between the concrete freeze-thaw failure surface and freeze-thaw cycles. Then the four-parameter failure surface model was set into ADINA finite element software program for secondary development to investigate the strength properties of concrete component under freeze-thaw action. The relationship between load and deflection of concrete was analyzed and simulated after 0, 25 and 50 freeze-thaw cycles. The simulated and experimental results are basically identical, which demonstrates that this finite element simulation is a feasible way to analyze and evaluate the performance of concrete structures in cold regions.
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Lu, Xiao-Chun, Bin Guan, Bo-Fu Chen, Xin Zhang, and Bo-bo Xiong. "The Effect of Freeze-Thaw Damage on Corrosion in Reinforced Concrete." Advances in Materials Science and Engineering 2021 (May 13, 2021): 1–13. http://dx.doi.org/10.1155/2021/9924869.
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The existing studies of the corrosion of reinforced concrete have mainly focused on the interface area and chemical ion erosion, ignoring the specific service environment of the reinforced concrete. In this study, the effect of freeze-thaw damage was investigated via corrosion experiments under different freeze-thaw cycle conditions. Steel reinforcement corrosion mass, ultimate pull-out force, corrosion rate, and bond slippage were chosen as characteristic parameters in the experiments, and scanning electron microscopy (SEM) analysis was used to explain the mechanism of action of freeze-thaw damage on corrosion. The results showed that, under identical corrosion conditions, the mass of steel reinforcement corrosion and corrosion rate increased by 39.6% and 39.7% when comparing 200 freeze-thaw cycles to 0 cycles, respectively. The ultimate pull-out force and bond slippage after 200 freeze-thaw cycles decreased by 73% and 31%, respectively, compared with 0 freeze-thaw cycles. In addition, SEM analysis indicated that microstructure damage caused by freeze-thaw cycles accelerated the corrosion reaction and decreased cementitious properties, leading to decreasing ultimate pull-out force and bond slippage. The effect of freeze-thaw cycles and steel reinforcement corrosion on the macro mechanical properties of concrete is not a simple superposition.
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Takahashi, Shunsuke, Akira Ando, Hiroshi Takagi, and Jun Shima. "Insufficiency of Copper Ion Homeostasis Causes Freeze-Thaw Injury of Yeast Cells as Revealed by Indirect Gene Expression Analysis." Applied and Environmental Microbiology 75, no. 21 (September 11, 2009): 6706–11. http://dx.doi.org/10.1128/aem.00905-09.
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ABSTRACT Saccharomyces cerevisiae is exposed to freeze-thaw stress in commercial processes, including frozen dough baking. Cell viability and fermentation activity after a freeze-thaw cycle were dramatically decreased due to freeze-thaw injury. Because this type of injury involves complex phenomena, the injury mechanisms are not fully understood. We examined freeze-thaw injury by indirect gene expression analysis during postthaw incubation after freeze-thaw treatment using DNA microarray profiling. The results showed that genes involved in the homeostasis of metal ions were frequently contained in genes that were upregulated, depending on the freezing period. We assessed the phenotype of deletion mutants of the metal ion homeostasis genes that exhibited freezing period-dependent upregulation and found that the strains with deletion of the MAC1 and CTR1 genes involved in copper ion homeostasis exhibited freeze-thaw sensitivity, suggesting that copper ion homeostasis is required for freeze-thaw tolerance. We found that supplementation with copper ions during postthaw incubation increased intracellular superoxide dismutase activity and intracellular levels of reactive oxygen species were decreased. Moreover, cell viability was increased by supplementation with copper ions. These results suggest that insufficiency of copper ion homeostasis may be one of the causes of freeze-thaw injury.
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Yang, Ye, Zongguang Sun, Yanhai Yang, Liang Yue, and Guanliang Chen. "Effects of Freeze–Thaw Cycles on Performance and Microstructure of Cold Recycled Mixtures with Asphalt Emulsion." Coatings 12, no. 6 (June 9, 2022): 802. http://dx.doi.org/10.3390/coatings12060802.
Full textAbstract:
Although it is widely recognized that freeze–thaw cycles have a great influence on the properties of asphalt pavement, a quantitative understanding of how freeze–thaw cycles affect cold recycled mixtures with asphalt emulsion (CRME) is so far still lacking. The main objective of the paper was to investigate the performance and microstructure of CRME under freeze–thaw cycles with different water saturation conditions. For this, air voids, high-temperature stability, low-temperature cracking resistance, and moisture susceptibility of CRME were analyzed based on laboratory tests. The micro-morphology and chemical composition of cement asphalt emulsified compound mortar were observed by scanning electron microscopy (SEM). Results showed air voids of CRME increase as freeze–thaw cycles increase; the high-temperature stability, low-temperature cracking resistance, and moisture susceptibility of CRME decrease as freeze–thaw cycles increase; the asphalt strips from the surface of hydration products, and the composite structure mainly consists of hydration products as freeze–thaw cycles increase; the microstructure of CRME is destroyed. The freeze–thaw cycles have a negative effect on the CRME performance and microstructure.
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Li, Guo, Jian Min Du, Xiao Suo Wu, and Kun Yang. "Resistance of Concrete to Na2SO4 Freeze-Thaw Cycles and Failure Mechanism Analysis." Key Engineering Materials 711 (September 2016): 335–42. http://dx.doi.org/10.4028/www.scientific.net/kem.711.335.
Full textAbstract:
Rapid freeze–thaw cycle experiments were carried out on concrete specimens with 0.4, 0.5, and 0.6 water–cement (w/c) ratio in 0% (tap water), 1%, and 5% Na2SO4 solutions, respectively, to study the performance of ordinary concrete resistance to sulfate freeze–thaw cycle. The specimens underwent visual inspection, and mass losses and relative dynamic elastic modulus (RDEM) were measured regularly. Scanning electron microscope observation and X-ray diffraction analysis were conducted on partial specimens after the freeze–thaw cycle experiment. Research results show that due to the coupling effects of freeze–thaw cycle and sulfate corrosion, freeze–thaw cycles of concrete in Na2SO4 solution caused more damages than in tap water. Higher Na2SO4 concentration produced severe damages. Concrete with different w/c ratios exhibit different sulfate freeze–thaw cycle resistances, and concrete with lower w/c ratio usually produces stronger resistance. RDEM loss is considered the control index to determine concrete failure. The corrosion products in Na2SO4 solution freeze–thaw cycle are mainly ettringite and gypsum. With the increase in Na2SO4 concentration, ettringite formation gradually decreases and gypsum formation gradually increases.