Air cooling of concrete by means of embedded cooling pipes—Part II: Application in design

Abstract

resumThis paper relates the second part of the investigation of air-cooling in concrete; the first part is presented in "Air cooling of concrete by means of embedded cooling pipesPart I: Laboratory tests and heat transfer coefficients" [1]. Embedded cooling pipes are used to reduce the risk of thermal cracking in early age concrete. Traditionally, water has been used as a cooling medium, but air cooling has been shown to be advantageous for many applications. The experimentally-determined heat transfer coefficients of cooling pipes [1], have been used and verified in comparisons of in situ measurements at the Igelsta Bridge in S6dertSlje, Sweden. The close agreement between measured and calculated temperatures of air-cooled sections seems to justify the use of the averaged heat transfer coefficients determined in [1].Some exemplifying calculations are also shown, and the general behaviour of cooled structures is discussed. The principles of designing a coohng system for a general case are proposed. It is concluded that it is possible to design prismatic structures, such as a columns, by the use of existing models and measured heat transfer coefficients.

Air cooling of concrete by means of embedded cooling pipes-Part I: Laboratory tests of heat transfer coefficients

“…Comparative calculations based on experimental results evaluated and presented here are in good agreement with in situ measurements of temperatures, see [1]. Since all other factors were well known in the comparison, the only outstanding parameter influencing the results was the heat transfer coefficient.…”

“…The results from the measurements have been used for comparison with calculations of the temperature development in the air-cooled sections and a good agreement has been achieved [1,16].…”

“…This paper relates to the first part of the investigation dealing with the laboratory tests of heat transfer coefficients. The second part, dealing with application in design, is presented in "Air cooling of concrete by means of embedded cooling pipes -Part II: Applications in design" [1]. …”

Active control of properties of concrete: a (p)review

“…Another type of active control involving a thermal field is given by cooling measures to mitigate thermal cracking in hardening massive concrete elements [ 23 ]. In embedded cooling pipes, a cooling agent is circulated through the massive element, imposing lower temperatures inside the hardening concrete [ 24 , 25 ]. All constituents of the concrete respond to the applied thermal signal (lower temperature in embedded cooling pipes) following the physical laws of thermal diffusion, as described by Fourier’s equation [ 26 ].…”

Influence Analysis of the Concrete Temperature Field with Different Computed Methods

“…The approximate method was a lumped parameter method, through loaded the average convective transfer coefficient on interface of the concrete and the water pipe to calculate the temperature near the concrete. The coupling method focused on the detailed interaction of complicated cooling water flow in the pipe with the heat transfer in the adjacent concrete by simultaneously treating the coupled water flow and heat transfer, so that the heat energy balance between the water and the concrete could be attained automatically and accurately [6][7][8][9][10] .…”