Transport and sorption phenomena in concrete and other porous media
(2000) In Report TVBM 1019 Abstract
 The work presented in this thesis is mainly focused on transport processes involved in service life predictions of concrete. Two papers and three reports deal with ion transport in pore solution of concrete. One paper and one report deals with moisture transport in concrete and the remaining papers and reports deal with absorption and physical properties related to adsorption for different materials. The fourteen contributions have the following contents:
<br>
RI:1, Diffusion of a mixture of positively and negatively charged ions in pore solution of concrete is studied. Binding of dissolved ions in pore solution and leaching of ions from solid components into pore solution are included in the model. The material... (More)  The work presented in this thesis is mainly focused on transport processes involved in service life predictions of concrete. Two papers and three reports deal with ion transport in pore solution of concrete. One paper and one report deals with moisture transport in concrete and the remaining papers and reports deal with absorption and physical properties related to adsorption for different materials. The fourteen contributions have the following contents:
<br>
RI:1, Diffusion of a mixture of positively and negatively charged ions in pore solution of concrete is studied. Binding of dissolved ions in pore solution and leaching of ions from solid components into pore solution are included in the model. The material constants in the developed model are chosen to give the best match of simulation to experimental data. A finite element scheme is developed solving the governing coupled constituent equations.
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RI:2, The models established in RI:1 and P:1 are used to study the effect of different cements and pozzolans on chloride ingress into concrete.
<br>
RI:3, The models established in RI:1 and P:1 are used to study the effect of curing conditions on chloride ingress in concrete. A drying period before exposure to chlorides is shown to decrease the penetration.
<br>
RII:1, Capillary suction is studied using a Newtonian fluid assumption together with a momentum source term reflecting the influence of the pore walls on the capillary sucked fluid.
<br>
RIII:1, The heat of adsorption of different molecule layers on dry surfaces is investigated using a calorimetric technique. Different types of BETequations were used to predict the distribution of adsorbate among different discrete adsorbed layers. The classical way of calculating the adsorption heat and the measured values differed with about a factor of 2.5.
<br>
RIII:2, The effect of different constant temperatures on the absorption isotherms and the heat of adsorption of first and second layer molecules on porous glass are investigated.
<br>
P:1, Diffusion of a mixture of positively and negatively charged ions in water is studied. An electrical potential is included in the model, which makes it possible to study diffusion caused by internal electrical forces in a mixture of different types of ions.
<br>
P:2, The paper presents a model for combined chloride ion diffusion and chloride ion convection caused by capillary suction.
<br>
P:3, A numerical approach capable of solving diffusionconvection equations is discussed. The socalled PetrovGalerkin weighting is shown to be a reliable method for the diffusion problem studied.
<br>
P:4, Four different methods of measuring sorption isotherms are studied.
<br>
P:5, The limit of the use of a quasistatic calorimetric technique measuring absorption is investigated theoretically by simulating the diffusion behavior in the instrument. Results shows that the material constant related to the sorption kinetics must exceed a certain value.
<br>
P:6, Measurements of moisture storage capacity with sorption balance and pressure extractor are described in this paper.
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P:7, In this paper microstructural changes caused by carbonation of cement mortar are discussed.
<br>
P:8, Water vapor diffusion and transient condensation in cement mortar are treated in this paper. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/record/40978
 author
 Johannesson, Björn ^{LU}
 opponent

 Docent Jonasson, JanErik, Division of Structural Engineering, LTU
 organization
 publishing date
 2000
 type
 Thesis
 publication status
 published
 subject
 keywords
 Durability, Sorption, Capillary suction, Diffusion, Convection, Concrete, Byggnadsteknik, Mixture Theory, Building construction
 in
 Report TVBM 1019
 pages
 502 pages
 publisher
 Division of Building Materials, LTH, Lund University
 defense location
 John Ericssons väg 1, V:A
 defense date
 20001110 10:15
 external identifiers

 other:ISRN: LUTVDG/TVBM00/1019SE(1227)
 ISSN
 03487911
 ISBN
 9162843516
 language
 English
 LU publication?
 yes
 id
 2ded2c6ae2424d048cc52e060b5a16a0 (old id 40978)
 date added to LUP
 20070910 10:46:38
 date last changed
 20160919 08:44:55
@phdthesis{2ded2c6ae2424d048cc52e060b5a16a0, abstract = {The work presented in this thesis is mainly focused on transport processes involved in service life predictions of concrete. Two papers and three reports deal with ion transport in pore solution of concrete. One paper and one report deals with moisture transport in concrete and the remaining papers and reports deal with absorption and physical properties related to adsorption for different materials. The fourteen contributions have the following contents:<br/><br> <br><br/><br> RI:1, Diffusion of a mixture of positively and negatively charged ions in pore solution of concrete is studied. Binding of dissolved ions in pore solution and leaching of ions from solid components into pore solution are included in the model. The material constants in the developed model are chosen to give the best match of simulation to experimental data. A finite element scheme is developed solving the governing coupled constituent equations.<br/><br> <br><br/><br> RI:2, The models established in RI:1 and P:1 are used to study the effect of different cements and pozzolans on chloride ingress into concrete.<br/><br> <br><br/><br> RI:3, The models established in RI:1 and P:1 are used to study the effect of curing conditions on chloride ingress in concrete. A drying period before exposure to chlorides is shown to decrease the penetration.<br/><br> <br><br/><br> RII:1, Capillary suction is studied using a Newtonian fluid assumption together with a momentum source term reflecting the influence of the pore walls on the capillary sucked fluid.<br/><br> <br><br/><br> RIII:1, The heat of adsorption of different molecule layers on dry surfaces is investigated using a calorimetric technique. Different types of BETequations were used to predict the distribution of adsorbate among different discrete adsorbed layers. The classical way of calculating the adsorption heat and the measured values differed with about a factor of 2.5.<br/><br> <br><br/><br> RIII:2, The effect of different constant temperatures on the absorption isotherms and the heat of adsorption of first and second layer molecules on porous glass are investigated.<br/><br> <br><br/><br> P:1, Diffusion of a mixture of positively and negatively charged ions in water is studied. An electrical potential is included in the model, which makes it possible to study diffusion caused by internal electrical forces in a mixture of different types of ions.<br/><br> <br><br/><br> P:2, The paper presents a model for combined chloride ion diffusion and chloride ion convection caused by capillary suction.<br/><br> <br><br/><br> P:3, A numerical approach capable of solving diffusionconvection equations is discussed. The socalled PetrovGalerkin weighting is shown to be a reliable method for the diffusion problem studied.<br/><br> <br><br/><br> P:4, Four different methods of measuring sorption isotherms are studied.<br/><br> <br><br/><br> P:5, The limit of the use of a quasistatic calorimetric technique measuring absorption is investigated theoretically by simulating the diffusion behavior in the instrument. Results shows that the material constant related to the sorption kinetics must exceed a certain value.<br/><br> <br><br/><br> P:6, Measurements of moisture storage capacity with sorption balance and pressure extractor are described in this paper.<br/><br> <br><br/><br> P:7, In this paper microstructural changes caused by carbonation of cement mortar are discussed.<br/><br> <br><br/><br> P:8, Water vapor diffusion and transient condensation in cement mortar are treated in this paper.}, author = {Johannesson, Björn}, isbn = {9162843516}, issn = {03487911}, keyword = {Durability,Sorption,Capillary suction,Diffusion,Convection,Concrete,Byggnadsteknik,Mixture Theory,Building construction}, language = {eng}, pages = {502}, publisher = {Division of Building Materials, LTH, Lund University}, school = {Lund University}, series = {Report TVBM 1019}, title = {Transport and sorption phenomena in concrete and other porous media}, year = {2000}, }