Shear creep behavior of red sandstone after freeze-thaw cycles considering different temperature ranges

2021 ◽  
Author(s):  
Dong Wang ◽  
Guoqing Chen ◽  
Dahua Jian ◽  
Jing Zhu ◽  
Zhiheng Lin
Keyword(s):  
Creep Behavior ◽  
Shear Creep ◽  
Red Sandstone ◽  
Freeze Thaw ◽  
Temperature Ranges

Investigation on Static Shear Creep Behavior of Asphalt Mastic Containing Recycled Red Brick Powder

2011 ◽  
Vol 306-307 ◽  
pp. 1707-1711 ◽  
Author(s):  
Yi Han Sun ◽  
Shao Peng Wu ◽  
Ji Qing Zhu ◽  
Jin Jun Zhong
Keyword(s):  
Creep Behavior ◽  
Mass Ratio ◽  
Creep Tests ◽  
Shear Creep ◽  
Stiffness Modulus ◽  
Asphalt Mastic ◽  
Burgers Model ◽  
Brick Powder ◽  
Creep Stiffness ◽  
Static Shear

The static shear creep behavior of asphalt mastic containing recycled red brick powder (RBP) is investigated in this paper. The used mastic consists of asphalt and filler at a mass ratio of 1:1. Dynamic Shear Rheometer (DSR) performed the static shear creep tests at 0°C. The static shear creep behavior of RBP asphalt mastic was analyzed and modeled based on Burgers model. It is concluded that the introduction of RBP results in smaller deformation, higher static shear creep stiffness modulus of asphalt mastic at 0°C. It was also indicated that Burgers model can well explain the static shear creep behavior of RBP asphalt mastic.

scholarly journals Research on the Pore Evolution of Sandstone in Cold Regions under Freeze-Thaw Weathering Cycles Based on NMR

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Zheng Pan ◽  
Keping Zhou ◽  
Rugao Gao ◽  
Zhen Jiang ◽  
Chun Yang ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Pore Structure ◽  
Western China ◽  
Cold Regions ◽  
Abrupt Decrease ◽  
Evolution Law ◽  
Red Sandstone ◽  
Freeze Thaw ◽  
Evolution Characteristics ◽  
Pore Evolution

The evolution of the rock pore structure is an important factor influencing rock mechanical properties in cold regions. To study the mesoscopic evolution law of the rock pore structure under freeze-thaw weathering cycles, a freeze-thaw weathering cycle experiment was performed on red sandstone from the cold region of western China with temperatures ranging from -20°C to +20°C. The porosity, T2 spectral distribution, and magnetic resonance imaging (MRI) characteristics of the red sandstone after 0, 20, 40, 60, 80, 100, and 120 freeze-thaw weathering cycles were measured by the nondestructive detection technique nuclear magnetic resonance (NMR). The results show that the porosity of sandstone decreases first and then increases with the increase of the freeze-thaw weathering cycles and reaches the minimum at 60 of freeze-thaw weathering cycles. The evolution characteristics of porosity can be divided into three stages, namely, the abrupt decrease in porosity, the slow decrease in porosity, and the steady increase in porosity. The evolution characteristics of the T2 spectrum distribution, movable fluid porosity (MFP), and MRI images in response to the freeze-thaw weathering process are positively correlated with the porosity. Analysis of the experimental data reveals that the decrease in the porosity of the red sandstone is mainly governed by mesopores, which is related to the water swelling phenomenon of montmorillonite. Hence, the pore connectivity decreases. As the number of freeze-thaw cycles increases, the effect of the hydrophysical reaction on the porosity gradually disappears, and the frost heaving effect caused by the water-ice phase transition gradually dominates the pore evolution law of red sandstone.

Coupled effects of chemical environments and freeze–thaw cycles on damage characteristics of red sandstone

2016 ◽  
Vol 76 (4) ◽  
pp. 1481-1490 ◽  
Author(s):  
Feng Gao ◽  
Qiaoli Wang ◽  
Hongwei Deng ◽  
Jian Zhang ◽  
Weigang Tian ◽  
...  
Keyword(s):  
Red Sandstone ◽  
Freeze Thaw ◽  
Damage Characteristics

scholarly journals Experimental Study on Freeze-Thaw Effects on Creep Characteristics of Rubber Concrete

2022 ◽  
Vol 2022 ◽  
pp. 1-14
Author(s):  
Qi Li ◽  
Fei Xu ◽  
Hemin Zheng ◽  
Junhao Shi ◽  
Jianyu Zhang
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Stress Level ◽  
Creep Behavior ◽  
Mass Loss Rate ◽  
Crumb Rubber ◽  
Dynamic Elastic Modulus ◽  
Freeze Thaw ◽  
Stress Levels ◽  
Rubber Concrete

Crumb Rubber Concrete (CRC) can exhibit high freeze-thaw resistance, but its long-term creep behavior under various freeze-thaw conditions remains unclear, which is essential for the safety of pavement engineering in the severe cold zone. In this study, the freeze-thaw effects on the creep behavior of CRC under different stress levels were systematically analyzed by testing the compressive strength, the uniaxial creep under different stress levels, and the dynamic elastic modulus. To simulate real conditions of the road environment in the cold area, the lowest temperature of −20°C, six freeze-thaw cycles of 0, 30, 60, 90, 120, and 150, and seven different stress levels of 0.4, 0.5, 0.6, 0.7, 0.8, and 0.9 of the compressive strength were employed in this study. The test results showed that the mass loss rate was 6%–11.2% and the compressive strength decreased by 6.51%–47% after 30–150 freeze-thaw cycles. When the stress level reached its critical value, the relative dynamic elastic modulus decreased with the number of freeze-thaw cycles. After 150 freeze-thaw cycles, failure did not appear when the stress level was lower than 50%, above which the creep failure was determined by the stress level and the number of the freeze-thaw cycles. Meanwhile, it was found that the cracking and interfacial debonding between the matrix and the crumb rubber particle were the main reasons for the degradation of CRC creep performance. Finally, a Weibull distribution-based empirical creep damage model was established to predict the failure of CRC, which can enhance its application to related engineering.

Creep behavior of soft clay subjected to artificial freeze–thaw from multiple-scale perspectives

2020 ◽  
Vol 15 (10) ◽  
pp. 2849-2864
Author(s):  
Jun Li ◽  
Yiqun Tang ◽  
Wei Feng
Keyword(s):  
Creep Behavior ◽  
Soft Clay ◽  
Multiple Scale ◽  
Freeze Thaw

Creep Behavior of PB-Free Solders

2001 ◽  
Author(s):  
F. Hua ◽  
C. M. Garner ◽  
H. G. Song ◽  
J. W. Morris
Keyword(s):  
Activation Energy ◽  
Creep Behavior ◽  
Solder Joints ◽  
Creep Process ◽  
Diffusion Activation Energy ◽  
Air Cooling ◽  
Shear Creep ◽  
Self Diffusion ◽  
Intermetallic Particles ◽  
Stress Levels

Abstract This study reports results of shear creep behavior of four Pb-free solders, Sn-3Ag-0.5Cu, Sn-3.5Ag, Sn-0.7Cu and Sn-10In-3.1Ag at 95θC and 130θC. At the stress levels tested, all the four solders showed the stress components close or larger than 5, typical for matrix creep. The calculated activation energies for Sn-0.7Cu, Sn-3.5Ag and Sn-3Ag-0.5Cu are from 103kJ/mol to 117kJ/mol, which are very close to the pure Sn self-diffusion activation energy (107kJ/mol). It suggested that the creep process is controlled by Sn bulk self-diffusion rate. The creep activation energy for Sn-10In-3.1Ag is higher in the range of 173–193kJ/mol. The Sn-0.7Cu, Sn-3Ag-0.5Cu and Sn-10In-3.1Ag solder joints were also prepared with two different cooling rates, 3.5θC/min. (furnace-cooling) and 2.7θC/S (air-cooling) and tested at 130θC. It was observed that faster cooled solder joints have faster creep strain rates than slower cooled solder joints at the stress levels tested for all three solders, due to the fine and even distribution of intermetallic particles.

scholarly journals Triaxial Creep Behavior of Red Sandstone in Freeze-Thaw Environments

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Yongjun Song ◽  
Yongxin Che ◽  
Leitao Zhang ◽  
Jianxi Ren ◽  
Shaojie Chen ◽  
...  
Keyword(s):  
Stress Level ◽  
Creep Deformation ◽  
Transverse Shear ◽  
Shear Plane ◽  
Confining Pressure ◽  
Term Strength ◽  
Red Sandstone ◽  
Freeze Thaw ◽  
Viscoelastic Strain

To investigate the time-dependent mechanical properties of rock masses in cold regions under the effects of freeze-thaw cycling and long-term loading, triaxial multilevel loading and unloading creep tests were performed on saturated red sandstone samples subjected to different numbers of freeze-thaw cycles. The effects of freeze-thaw cycles and confining pressure on the creep properties, long-term strength, and creep failure mode of the rock were analyzed. The effect of freeze-thaw cycles on the microstructure of the rock was analyzed using scanning electron microscopy. The results showed that as the number of freeze-thaw cycles increased, the rock particle boundaries became more distinct, and more pores formed. The effect of freeze-thaw cycles on the creep deformation of red sandstone was related to the loading stress level. At low stress levels, the rock viscoelastic strain increased gradually and almost linearly with an increasing number of freeze-thaw cycles; in contrast, at high stress levels, the rock viscoelastic strain increased nonlinearly. The viscoplastic strain increased almost linearly with increasing freeze-thaw cycles. The fourth loading stress level (70% σ c ) corresponded to the transition of the creep deformation of the red sandstone. When the confining pressure was low, a higher stress level caused the confining pressure to have a more significant effect on the creep strain. However, as the confining pressure continued to increase, the effect of the confining pressure on the creep strain eventually disappeared. The long-term strength of the red sandstone decreased approximately linearly with an increase in the number of freeze-thaw cycles. When the number of freeze-thaw cycles and the confining pressure were high, the rock samples formed a transverse shear plane and were more fragmented than those without a transverse shear plane. These results provide a reference for construction in rock mass engineering and long-term stability analysis in cold regions.

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