scholarly journals RELATIONSHIP BETWEEN ATMOSPHERIC TEMPERATURE VARIATION AND THE SHIRINKAGE CRACKING IN CONCRETE STRUCTURE : Part 2, Creep of Concrete in Tension (or Flexure) Corresponding to Atmospheric Temperature Variation

1975 ◽  
Vol 237 (0) ◽  
pp. 23-32
Author(s):  
MASATOSHI NAKANISHI
Keyword(s):  
Temperature Variation ◽  
Concrete Structure ◽  
Atmospheric Temperature

scholarly journals The lunar diurnal variation of atmospheric temperature at Batavia, 1866-1928

1932 ◽  
Vol 137 (831) ◽  
pp. 1-24 ◽  
Keyword(s):  
Heat Flow ◽  
Temperature Variation ◽  
Wave Length ◽  
Barometric Pressure ◽  
Atmospheric Temperature ◽  
Vertical Flow ◽  
Tidal Changes ◽  
Long Time ◽  
Semidiurnal Variation ◽  
Established Fact

The existence of a lunar tide in the earth’s atmosphere is now a well-established fact. It is indicated by a lunar semidiurnal variation of barometric pressure, found at every station for which the necessary reductions have been made. Now a variation of pressure in a gas is in general accompanied by a variation of temperature. The amount of this variation depends on the rate at which heat can flow in the gas, from a region of compression to one of rarefaction, or from the earth or ocean to or from the gas. The maximum variation of temperature corresponds to adiabatic changes of pressure, while if the heat flow can be very rapid, the temperature variation may be reduced almost to zero, corresponding to isothermal changes of pressure. I have shown that the lunar tidal changes of pressure will be almost adiabatic so far as concerns heat flow in the gas , between regions of compression and of rarefaction. The long time available for equalisation of temperature, viz., a quarter of a lunar day, or about 6 hours, is in fact ineffective because of the long wave-length of the tide, the distance between the regions of highest or lowest pressure in any latitude being a quarter of the circumference of the circle of latitude. The temperature variation might be reduced below the adiabatic value if vertical flow of heat, between the air and the ground or ocean, is sufficiently rapid. This point will be discussed in another paper; the conclusion reached is that the vertical flow of heat is unlikely to be important over the land . Hence a temperature variation approaching the adiabatic value is likely to be associated with the lunar atmospheric tide at a land station.

The impact of uneven temperature distribution on stability of concrete structures using data analysis and numerical approach

2020 ◽  
pp. 136943322095061
Author(s):  
Xuyan Tan ◽  
Weizhong Chen ◽  
Luyu Wang ◽  
Jianping Yang
Keyword(s):  
Temperature Distribution ◽  
Tensile Stress ◽  
Statistical Model ◽  
Temperature Variation ◽  
Concrete Structure ◽  
Shield Tunnel ◽  
Structure Stability ◽  
Mechanical Behaviors ◽  
Analytical Results

Temperature variation is an essential factor to influence the stability of concrete structure. In contrast to the uniform distribution of temperature in most existing approaches, this paper aims to study the natural temperature distribution in concrete structure and analyze its impact on structural mechanical behaviors in field. As a case study, an underwater shield tunnel is investigated using the presented method. Firstly, temperature sensors are installed in different positions to achieve real-time monitoring in field. Then, a statistical model is derived by monitoring data to describe temperature variation. As a core component of the approach, the devised statistical model is integrated into our program to determine the external loads imposed on model. Finally, the mechanical behaviors of concrete structure are discussed under uneven temperature distribution. Analytical results indicated the magnitudes of temperature distribution is related to different positions of structure, in which the significant distinctions can be observed at upper and lower of tunnel as well as the inside and outside structures. Also, the tensile stress of tunnel lining increases with the rise of temperature, for instance, in this case study per temperature rising would lead to an increment 25.3 KPa of tensile stress. As a promising application, the analytical results provide an assessment of concrete structure stability.

TEMPERATURE COMPENSATOR 30 and 32

Alloy Digest ◽  
1957 ◽  
Vol 6 (10) ◽  
Keyword(s):  
Physical Properties ◽  
Surface Treatment ◽  
Temperature Variation ◽  
Magnetic Permeability ◽  
Temperature Compensation ◽  
Heat Treating ◽  
Atmospheric Temperature ◽  
Iron Alloys ◽  
Nickel Iron ◽  
Electrical Apparatus

Abstract TEMPERATURE COMPENSATOR 30 and 32 are nickel-iron alloys whose magnetic permeability decreases proportionally with increasing temperatures within the usual range of atmospheric temperature variation. They are recommended for temperature compensation applications in electrical apparatus. This datasheet provides information on composition, physical properties, and elasticity. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: Fe-15. Producer or source: Carpenter.

scholarly journals Atmospheric Temperature Variation after the 1991 Mt. Pinatubo Eruption

1992 ◽  
Vol 70 (6) ◽  
pp. 1161-1166 ◽  
Author(s):  
Masahiro Kawamata ◽  
Shingo Yamadal ◽  
Tatsuya Kudoh ◽  
Kiyoharu Takano ◽  
Shoji Kusunoki
Keyword(s):  
Temperature Variation ◽  
Atmospheric Temperature ◽  
Pinatubo Eruption

Temperature analysis of CFG pile composite foundation in high latitudes and low altitude island permafrost

2019 ◽  
Vol 10 (1) ◽  
pp. 85-101 ◽  
Author(s):  
Jinliang Liu ◽  
Yanmin Jia
Keyword(s):  
Temperature Variation ◽  
Atmospheric Temperature ◽  
Composite Foundation ◽  
Maximum Temperature ◽  
Temperature Cycle ◽  
Content Type ◽  
Foundation Treatment ◽  
Low Altitude ◽  
Cfg Pile Composite Foundation ◽  
Cfg Pile

Purpose Cement fly ash gravel (CFG) pile composite foundation is an effective and economic foundation treatment approach, which is significant to build foundation, subgrade construction, and so forth. The purpose of this paper is to present a research on the temperature behaviours of high-latitude and low-altitude island permafrost under CFG pile composite foundation treatment. Design/methodology/approach In the process of CFG pile construction, the temperature of permafrost and pile body was monitored using the temperature sensors. The influence of subgrade height and atmospheric temperature cycle on permafrost temperature was analysed by finite element simulation. Findings In the process of CFG pile construction, the change curve of pile temperature and the temperature of permafrost beside pile following time can be divided into six stages, and the duration of these stages is at least one month. The temperature variation of permafrost while constructing subgrade in FEM has a good agreement with the results of field temperature monitoring. The height of subgrade not only affects the maximum temperature increase of permafrost and the re-frozen time of permafrost after the construction of CFG pile composite foundation, but also affects the temperature variation amplitude of permafrost during atmospheric temperature cycle. Originality/value The research will provide a reference for the design on the CFG pile composite foundation used for island permafrost and guarantee the stability of the structure; thus, it has an important significance.

scholarly journals Time-Dependent Behavior of Shrinkage Strain for Early Age Concrete Affected by Temperature Variation

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Yu Qin ◽  
Zhijian Yi ◽  
Weina Wang ◽  
Di Wang
Keyword(s):  
Temperature Variation ◽  
Thermal Strain ◽  
Shrinkage Strain ◽  
Atmospheric Temperature ◽  
Time Dependent ◽  
Early Age ◽  
Dependent Behavior ◽  
Engineering Problems ◽  
The Difference ◽  
Early Age Concrete

Shrinkage has been proven to be an important property of early age concrete. The shrinkage strain leads to inherent engineering problems, such as cracking and loss of prestress. Atmospheric temperature is an important factor in shrinkage strain. However, current research does not provide much attention to the effect of atmospheric temperature on shrinkage of early age concrete. In this paper, a laboratory study was undertaken to present the time-dependent shrinkage of early age concrete under temperature variation. A newly developed Material Deformation Tester (MDT), which can simulate consecutive variation of atmospheric temperature, was used to collect the shrinkage strain of specimens and temperature data. A numerical model was established to describe the thermoelastic strain of a specimen. The results show that (1) there are several sharp shrinkages up to 600 μfor early age concrete in the first 3 days; (2) the absolute value of shrinkage strain is larger than thermal strain; and (3) the difference of shrinkage strain under temperature variation or constant temperature is up to 500 μ.

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