- The study examined the performance of concrete mixtures combining calcium sulphoaluminate (CSA) cement and vaterite, a form of calcium carbonate, as a filler. - Tests on compressive strength, setting time, and heat evolution showed that adding calcite or vaterite fillers resulted in slightly slower set times and lower compressive strengths compared to mixtures without fillers. - However, the performance of calcite and vaterite fillers was similar in terms of set times, strength, and heat evolution at early ages, despite differences in their particle sizes and chemical properties.

1. An
Analysis
on
the
Combina0on
of
CSA
Cement
and
Vaterite
Emmanuel
Flores,
Craig
W.
Hargis,
and
Paulo
J.
M.
Monteiro,
Ph.
D.
Department
of
Civil
and
Environmental
Engineering,
University
of
California,
Berkeley,
94720
CSA_G0
CSA_G0_C10
CSA_G0_V10
Time
(Days)
1
7
1
7
1
7
Mean
(lbs.)
8787
12617
7657
10433
7313
8617
Standard
DeviaTon
(lbs.)
710
777
332
751
379
580
RSD
(%)
8.08
6.16
4.33
7.19
5.18
6.73
CSA_G0
CSA_G0_C10
CSA_G0_V10
Time
(min.)
PenetraTon
(mm)
Time
(min.)
PenetraTon
(mm)
Time
(min.)
PenetraTon
(mm)
5
40
(boWom)
5
40
(boWom)
5
40
(boWom)
10
40
(boWom)
10
40
(boWom)
10
40
(boWom)
15
40
(boWom)
15
40
(boWom)
15
40
(boWom)
20
34
20
40
(boWom)
20
40
(boWom)
25
14
25
32
25
30
30
3
30
21
30
15
35
10
35
2
Final
Set
(min.)
36
42
43
Compression
Strength
Table
1.
The
staTsTcs
for
the
compressive
strength
of
concrete
samples.
3
concrete
mixes
were
tested.
Isothermal
Calorimetry
Figure
5.
Results
of
this
test
provide
the
amount
of
heat
released
by
the
specimens
over
the
course
of
Tme.
This
was
done
on
6
different
concrete
mixes.
Calcium
sulphoaluminate
cement
(CSA
cement)
has
become
a
possible
low-­‐CO2
and
economically
viable
alterna0ve
to
the
commonly-­‐used
portland
cement.
This
is
the
result
of
the
differences
found
in
each
cement
in
how
it
is
extracted
and
processed.
CSA
cement
has
significantly
lower
CO2
emissions
because
it
can
be
made
from
industrial
by-­‐products
and
requires
a
lower
processing
temperature
than
portland
cement.
Another
alternaTve
that
is
being
explored
is
the
use
of
vaterite
as
filler
which
parTally
replaces
the
cement
for
concrete
mixes.
Vaterite
is
a
more
reac0ve
form
of
CaCO3
and
was
designed
to
capture
CO2.
This
study
examined
the
performance
of
concrete
specimens
that
combined
CSA
cement
and
vaterite,
as
a
filler,
through
compression
strength,
set
Tme,
and
isothermal
calorimetry
tests.
Vaterite
was
compared
with
the
performance
of
calcite
and
gypsum
fillers.
Abstract
• Using
the
concrete
mix
which
had
no
fillers
as
a
reference,
the
addiTon
of
calcite
or
vaterite
causes
a
slight
slowing
in
the
set
Tme
of
concrete.
• The
addiTon
of
calcite
or
vaterite
results
in
lower
compressive
strengths
when
compared
to
concrete
mixes
that
had
no
filler.
This
was
true
for
24
hours
(1
day)
and
7
days.
• Despite
the
differences
in
size
of
parTcles
and
energy
states
between
calcite
and
vaterite,
there
are
no
real
differences
in
performance
between
the
two
in
terms
of
set
Tmes,
compression
strength,
and
heat
evoluTon
at
early
ages.
Conclusions
• Perform
compressive
strength
tests
on
concrete
mixes
that
combine
CSA
cement,
gypsum,
and
either
calcite
or
vaterite.
• Referencing
the
performance
of
CSA
concrete
with
concrete
specimens
made
with
portland
cement.
Future
Direc0ons
A
special
thanks
to:
• Professor
Paulo
J.
M.
Monteiro
• Craig
W.
Hargis
• Cal
NERDS:
Diana
Lizarraga,
Michele
De
Coteau,
Chris
Noble
Acknowledgements
Set
Times
Table
2.
Results
from
this
test
for
3
different
concrete
mixes.
The
final
set
Tme
was
interpolated
using
the
last
two
data
points
of
each
mix.
Preliminary
Results
(cont.)
References
• Images
used
to
design
the
poster
(sidebar)
were
taken
from
(Aug.
7,
2012):
hWp://publish.neTtor.com/photos/schools/cal/nonsport/faciliTes/memorial-­‐stadium.jpg
hWp://us.123rf.com/400wm/400/400/rcpphoto/rcpphoto0812/
rcpphoto081200073/3951192-­‐reinforced-­‐steel-­‐-­‐concrete-­‐building-­‐skyscraper.jpg
hWp://www.inhabitat.com/wp-­‐content/uploads/sollewit-­‐jeff-­‐ed01.jpg
hWp://www.designboom.com/cms/images/ridnew/toyocon04.jpg
hWp://www.sutmundo.com/wp-­‐content/uploads/2010/10/concrete.jpg
• Figure
3
was
taken
from
(Aug.
7,
2012)
:
hWp://media.americanlaboratory.com/m/20/ArTcle/36163-­‐fig2.jpg
Methods
Test
1:
Compressive
Strength
Figure
1.
Test
3:
Isothermal
Calorimetry
Figure
3.
Test
2:
Set
Time
Figure
2.
• Figure
1.
Half-­‐inch
concrete
cube
being
compressed.
• Figure
2.
Freshly-­‐made
concrete
being
subjected
to
Vicat
test.
• Figure
3.
Isothermal
conducTon
calorimetry
machine.
Preliminary
Results
ParTcle
Size
Analysis
Figure
4.
Results
from
this
analysis
reveal
the
range
of
the
diamaters
for
the
parTcles
found
in
CSA
cement
and
the
fillers.