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Finite element analysis of temperature in hardening concrete using isothermal calorimetric data

Mac, John LU (2017) In TVSM-5000 VSM820 20171
Structural Mechanics
Department of Construction Sciences
Abstract
The produced heat in hardening concrete is of special importance to consider as the temperature rise within a large concrete structure can become such high that the structure may experience thermal cracking. With use of a simulation program that is based on the finite element method, the temperatures within the structure can be estimated to predict possible crack development.

The heat produced by the cement is normally modelled with conventional methods that is based on semi-adiabatic measurements. However, recently isothermal calorimetry has been discussed as a method that measures the heat of the cement more accurate.

The objective of this dissertation is to develop an algorithm to compute thermal power of hardening concrete using... (More)
The produced heat in hardening concrete is of special importance to consider as the temperature rise within a large concrete structure can become such high that the structure may experience thermal cracking. With use of a simulation program that is based on the finite element method, the temperatures within the structure can be estimated to predict possible crack development.

The heat produced by the cement is normally modelled with conventional methods that is based on semi-adiabatic measurements. However, recently isothermal calorimetry has been discussed as a method that measures the heat of the cement more accurate.

The objective of this dissertation is to develop an algorithm to compute thermal power of hardening concrete using isothermal calorimetric data for finite element analysis. To examine how simulations with isothermal calorimetric data performs in comparison to the conventional method for thermal analysis of concrete, an experimental setup was built containing the same concrete as isothermal calorimetric data was attained for.

The implementation of the algorithm was successful and now HACON is able to perform simulations with isothermal calorimetric data. The conclusion of the thermal analysis is that simulation with the isoconversional method and with the conventional method gives slightly different results.

The experimental setup was also built successfully by Flemark, however, due to the complex air flow surrounding the setup, it wasn't possible to attain a definite conclusion whether finite element analysis based on heat calculations according to isoconversion is more accurate than the conventional method. The conclusion is that a program has been successfully developed but further work needs to be made to validate the accuracy. (Less)
Popular Abstract
The risk of thermal cracks are of concern for massive concrete structures, mostly associated with dams, bridge piers and other structures with large volume placements. The consequence of thermal cracks in concrete can be severely reduced service lifetime.
Please use this url to cite or link to this publication:
author
Mac, John LU
supervisor
organization
course
VSM820 20171
year
type
H3 - Professional qualifications (4 Years - )
subject
keywords
isoconversion, isothermal calorimetry, thermal analysis, finite element method, numerical simulation
publication/series
TVSM-5000
report number
TVSM-5221
ISSN
0281-6679
language
English
id
8918490
alternative location
http://www.byggmek.lth.se/english/publications/tvsm-5000-masters-dissertations/
date added to LUP
2017-08-28 12:17:40
date last changed
2017-08-28 12:17:40
@misc{8918490,
  abstract     = {The produced heat in hardening concrete is of special importance to consider as the temperature rise within a large concrete structure can become such high that the structure may experience thermal cracking. With use of a simulation program that is based on the finite element method, the temperatures within the structure can be estimated to predict possible crack development.

The heat produced by the cement is normally modelled with conventional methods that is based on semi-adiabatic measurements. However, recently isothermal calorimetry has been discussed as a method that measures the heat of the cement more accurate. 

The objective of this dissertation is to develop an algorithm to compute thermal power of hardening concrete using isothermal calorimetric data for finite element analysis. To examine how simulations with isothermal calorimetric data performs in comparison to the conventional method for thermal analysis of concrete, an experimental setup was built containing the same concrete as isothermal calorimetric data was attained for. 

The implementation of the algorithm was successful and now HACON is able to perform simulations with isothermal calorimetric data. The conclusion of the thermal analysis is that simulation with the isoconversional method and with the conventional method gives slightly different results. 

The experimental setup was also built successfully by Flemark, however, due to the complex air flow surrounding the setup, it wasn't possible to attain a definite conclusion whether finite element analysis based on heat calculations according to isoconversion is more accurate than the conventional method. The conclusion is that a program has been successfully developed but further work needs to be made to validate the accuracy.},
  author       = {Mac, John},
  issn         = {0281-6679},
  keyword      = {isoconversion,isothermal calorimetry,thermal analysis,finite element method,numerical simulation},
  language     = {eng},
  note         = {Student Paper},
  series       = {TVSM-5000},
  title        = {Finite element analysis of temperature in hardening concrete using isothermal calorimetric data},
  year         = {2017},
}