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- Title
液氮泄漏对超导电缆管线槽混凝土 物理力学性质的影响.
- Authors
姚周飞; 杜习周; 王叶娇; 张政
- Abstract
Liquid nitrogen cooling auxiliary system is applied in the high temperature superconducting power transmission technique to reach the superconducting critical temperature of the cable. The cable can realize high density currents transmission in a low-cost, efficient and environmental-friendly way. Note that, the cable pipeline will be undergoing an extremely low temperature freezing and thawing problems. The ultrasonic tests, uniaxial compressive strength tests and nuclear magnetic resonance tests were performed on C25 concrete with different freezing and thawing cycles. The results show that the decrease in ultrasonic wave speed and the deterioration of compressive strength of concrete are caused by the freeze-thaw cycles. The ultrasonic wave speed and uniaxial compressive strength of concrete show a similar trend with the increasing freeze-thaw cycles. After four freeze-thaw cycles, the ultrasonic wave velocity reduced by 13.6%. While the uniaxial compressive strength decreased over 28%. Moreover, NMR tests revealed the changes in the micropores of C25 concrete under different freeze-thaw cycles. Test results show that the porosity increased with the increasing of freeze thaw cycles. The decrease of ultrasonic wave velocity and peak strength of concrete can be attributed to the increasing total porosity and the rising ratio of larger capillary pores to smaller ones caused by the freezing and thawing cycles.
- Publication
Science Technology & Engineering, 2022, Vol 22, Issue 27, p12117
- ISSN
1671-1815
- Publication type
Article