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LUND UNIVERSITY LIBRARIES

Luftporsystem i betong med mald granulerad masugnsslagg

Wennerberg, Elin LU (2026) In LUTVDG/TVBM VBML05 20261
Division of Building Materials
Abstract (Swedish)
Betong är ett mycket vanligt förekommande byggmaterial som har flera styrkor, men också
några svagheter. En av de väsentligaste svagheterna är de betydande koldioxidutsläpp som
uppstår vid tillverkningen av det nödvändiga bindemedlet portlandcement. Att ersätta delar av
portlandcementet med alternativa bindemedel är den mest effektiva och snabbaste insatsen för
att minska betongens klimatpåverkan. Eftersom användningen av alternativa bindemedel ökar
finns ett behov av att förstå luftporsystemet i betong med alternativa bindemedel bättre.
Luftporsystemet i betong är avgörande för flera av betongens egenskaper. Då luftporsystemet
påverkas av flera faktorer är det en utmaning att säkerställa ett lämpligt och stabilt
... (More)
Betong är ett mycket vanligt förekommande byggmaterial som har flera styrkor, men också
några svagheter. En av de väsentligaste svagheterna är de betydande koldioxidutsläpp som
uppstår vid tillverkningen av det nödvändiga bindemedlet portlandcement. Att ersätta delar av
portlandcementet med alternativa bindemedel är den mest effektiva och snabbaste insatsen för
att minska betongens klimatpåverkan. Eftersom användningen av alternativa bindemedel ökar
finns ett behov av att förstå luftporsystemet i betong med alternativa bindemedel bättre.
Luftporsystemet i betong är avgörande för flera av betongens egenskaper. Då luftporsystemet
påverkas av flera faktorer är det en utmaning att säkerställa ett lämpligt och stabilt
luftporsystem.

Målsättningarna med arbetet var att undersöka om val av flyttillsatsmedel och luftporbildande
tillsatsmedel samt blandningstid påverkade bildandet av luftporsystemet i betong med mald
granulerad masugnsslagg. Tillsatsmedel från två tillverkare samt två olika blandningstider
utvärderades. För betong innehållande mald granulerad masugnsslagg undersöktes
luftporsystem, konsistens och tryckhållfasthet. Luftporsystemet bestämdes med hjälp av
AVA, tunnslipsanalys och tryckmetoden.

Resultaten visade att luftporsystemet varierade beroende på vilket flyttillsatsmedel och
luftporbildande tillsatsmedel som användes. Tillsatsmedel från den ena tillverkaren
resulterade nästan genomgående i högre lufthalt, lägre avståndsfaktor, större specifik yta och
större andel mikroporer än tillsatsmedel från den andra tillverkaren. Vidare visade resultaten
att blandningstiden påverkade luftporsystemet, men att effekten varierade mellan
blandningsrecepten. En längre blandningstid tenderade att resultera i högre lufthalt, lägre
avståndsfaktor och större specifik yta för betong enligt det ena blandningsreceptet, medan
motsatsen gällde för det andra blandningsreceptet. Således indikerar detta att valet av
flyttillsatsmedel och luftporbildande tillsatsmedel samt blandningstid påverkar bildandet av
luftporsystemet i betong med mald granulerad masugnsslagg. (Less)
Abstract
Concrete is one of the most widely used construction materials, offering several advantages
but also presenting certain limitations. One of its most significant drawbacks is the substantial
carbon dioxide emissions associated with the production of Portland cement, the essential
binder in concrete. Replacing portions of Portland cement with alternative binders is
considered the most effective and rapid measure for reducing the climate impact of concrete.
As the use of alternative binders continues to increase, there is a growing need for a better
understanding of the air-void system in concrete containing such binders. The air-void system
plays a crucial role in several properties of concrete. Since it is influenced by... (More)
Concrete is one of the most widely used construction materials, offering several advantages
but also presenting certain limitations. One of its most significant drawbacks is the substantial
carbon dioxide emissions associated with the production of Portland cement, the essential
binder in concrete. Replacing portions of Portland cement with alternative binders is
considered the most effective and rapid measure for reducing the climate impact of concrete.
As the use of alternative binders continues to increase, there is a growing need for a better
understanding of the air-void system in concrete containing such binders. The air-void system
plays a crucial role in several properties of concrete. Since it is influenced by multiple factors,
ensuring an appropriate and stable air-void system remains a challenge.

The objectives of this study were to investigate whether the choice of superplasticizer and air
entraining admixture, as well as mixing time, affected the formation of the air-void system in
concrete containing ground granulated blast-furnace slag. Admixtures from two different
manufacturers and two different mixing times were evaluated. For concrete containing ground
granulated blast-furnace slag, the air-void system, workability, and compressive strength were
investigated. The air-void system was determined using AVA, thin-section analysis, and the
pressure method.

The results showed that the air-void system varied depending on the type of superplasticizer
and air-entraining admixture used. Admixtures from one manufacturer generally resulted in
higher air content, lower spacing factor, larger specific surface, and a higher proportion of
microvoids compared to admixtures from the other manufacturer. Furthermore, the results
showed that mixing time affected the air-void system, although the effect varied between mix
designs. A longer mixing time tended to result in higher air content, lower spacing factor, and
larger specific surface for one mix design, whereas the opposite trend was observed for the
other. Thus, the results indicate that the choice of superplasticizer and air-entraining
admixture, as well as mixing time, influences the formation of the air-void system in concrete
containing ground granulated blast-furnace slag. (Less)
Please use this url to cite or link to this publication:
author
Wennerberg, Elin LU
supervisor
organization
course
VBML05 20261
year
type
M2 - Bachelor Degree
subject
keywords
Betong, alternativa bindemedel, luftporsystem, lufthalt, avståndsfaktor, frostbeständighet, tillsatsmedel, blandningstid.
publication/series
LUTVDG/TVBM
report number
5150
other publication id
LUTVDG/TVBM-26/5150-SE
language
Swedish
id
9241251
date added to LUP
2026-06-18 12:07:31
date last changed
2026-06-18 12:07:31
@misc{9241251,
  abstract     = {{Concrete is one of the most widely used construction materials, offering several advantages 
but also presenting certain limitations. One of its most significant drawbacks is the substantial 
carbon dioxide emissions associated with the production of Portland cement, the essential 
binder in concrete. Replacing portions of Portland cement with alternative binders is 
considered the most effective and rapid measure for reducing the climate impact of concrete. 
As the use of alternative binders continues to increase, there is a growing need for a better 
understanding of the air-void system in concrete containing such binders. The air-void system 
plays a crucial role in several properties of concrete. Since it is influenced by multiple factors, 
ensuring an appropriate and stable air-void system remains a challenge.
 
The objectives of this study were to investigate whether the choice of superplasticizer and air
entraining admixture, as well as mixing time, affected the formation of the air-void system in 
concrete containing ground granulated blast-furnace slag. Admixtures from two different 
manufacturers and two different mixing times were evaluated. For concrete containing ground 
granulated blast-furnace slag, the air-void system, workability, and compressive strength were 
investigated. The air-void system was determined using AVA, thin-section analysis, and the 
pressure method.
 
The results showed that the air-void system varied depending on the type of superplasticizer 
and air-entraining admixture used. Admixtures from one manufacturer generally resulted in 
higher air content, lower spacing factor, larger specific surface, and a higher proportion of 
microvoids compared to admixtures from the other manufacturer. Furthermore, the results 
showed that mixing time affected the air-void system, although the effect varied between mix 
designs. A longer mixing time tended to result in higher air content, lower spacing factor, and 
larger specific surface for one mix design, whereas the opposite trend was observed for the 
other. Thus, the results indicate that the choice of superplasticizer and air-entraining 
admixture, as well as mixing time, influences the formation of the air-void system in concrete 
containing ground granulated blast-furnace slag.}},
  author       = {{Wennerberg, Elin}},
  language     = {{swe}},
  note         = {{Student Paper}},
  series       = {{LUTVDG/TVBM}},
  title        = {{Luftporsystem i betong med mald granulerad masugnsslagg}},
  year         = {{2026}},
}