presentation held at conference Nuremburg april 2017 on the topic WHITE CALCIUM SULPHO ALUMINATE CEMENT

1. April 3, 2017
The 6th International Drymix Mortar
Conference Nürnberg

2. agenda
INTRODUCTION
White cement , production , phase formation
ADJUST
calcium aluminate CAC , CSA WHITE ,ACA
calcium sulfate
SHRINKAGE DRY-MIX
problems and how to overcome them
CONCLUSION
closing

3. White Portlandcement
raw feed ; limestone + kaolin + sand
high energy consumption (~1600°C )
sintering
low impurity raw materials
clinker cooled quickly (water quenching)
decorative use

4. main phase composition
C3S alite
C2S belite
C3A tri calcium aluminate
CaSO4 calcium sulfate (≤ 5%)
(added at grinding stage )

5. hydration
high alkali
fCaO (efflorescence , lime bloom)
shrinkage
long setting time
slow strength development

6. replacement or part replacement of White Portlandcement
by source of high aluminum containing cement ;
reduce alkalinity
prevent efflorescence (lime bloom)
accelerate set
increase early strength
improve color consistency / sustainability
adjust

7. alumina cement
White calcium aluminate cement (CAC)
White calcium sulfo aluminate cement (CSA)
Amorphous calcium aluminate (ACA)

8. CAC WHITE
raw feed ; refined alumina+ limestone
refractory cement
sintering
calcination temperature ( ~1550° C.)
grinding clinker (blaine 4200-4600 g/cm2)
main phase composition CA +CA2
(monocalcium aluminate+calcium di-aluminate)

9. CSA WHITE
raw feed ; white bauxite + limestone + calcium sulphate
choice of high purity raw materials
sintering
tight control calcination (1250~1300° C.)
cooling of clinker
grinding clinker high fineness
(blaine 4800-5200 g/cm2)
main phase composition C4A3Š +C2S
(calcium aluminum sulfate hydroxide+belite)

10. ACA
raw feed ; bauxite + limestone
fused
calcination temperature ( ~1700° C.)
rapid cooling
grinding clinker (blaine 6000 g/cm2)
main phase composition C12A7 + CA
(mayenite+monocalcium aluminate)

11. calcium sulfate
a chemical reaction of aluminum , calcium and sulphate
ions forms calcium aluminum sulfate hydroxide , ettringite
crystals (Aft)
tetra calcium tri aluminate sulfate (C4A3Š)
3(CaO.Al2O3.3CaSO4.32H2O)
ettrinigite crystals;
needle-rod-, hexagonal, shaped
average size 1 ~ 7 μ

12. early ettringite formation
ternary cement matrix ;
compensation of shrinkage – expanding in volume
increase of initial strength – sulfate ions go in solution more rapid
than aluminate and silicate phase
accelerated drying - mobs up excess water ,32 water molecules
higher density - filling pores and cavities
amount and type of sulfate variable

13. shrinkage dry-mix
volume change
plastic
chemical
(autogenous)
drying
carbonation
water evaporation
smaller volume through
hydration
loss of water from gel pores
CO2 carbonation of
calcium hydroxide

14. practical
3 white formulations;
tile grout
fast setting tile adhesive
self leveling topping mortar
Mix 1 based on CAC White and Mix 2 on CSA WHITE

15. tile grout
substrate
tile adhesive
grout shrinks
leaving voids

16. water enters
substrate
water
penetrating

17. bond strength reduced
loss of strength
adhesive
substrate
grout
falls out

18. tile grout
Tile Grout - white
Mix 1.
Tile Grout - white
Mix 2.
OPC white 258 OPC white 275
CAC white 88,5 CSA white 75
Calcium sulfate 36 Calcium sulfate 26
Limestone filler 591 Limestone filler 601
Cellulose ether 1 Cellulose ether 1
Polymer powder 20 Polymer powder 20
Accelerator 1 Accelerator 1
Retarder 1,5 Retarder 1
Shrinkage compensation agent 3
Shrinkage compensation
agent
Total 1000 Total 1000
open time 30~40 min.- final set 3~4 hrs.

19. compressive strength MPa
0
5
10
15
20
25
1 day 7 day 28 day
Mix 1.
Mix 2.

20. flexural strength MPa
0
1
2
3
4
5
6
1 day 7 day 28 day
Mix 1.
Mix 2.

21. shrinkage/expansion 28 days
-0,045
-0,04
-0,035
-0,03
-0,025
-0,02
-0,015
-0,01
-0,005
0
Mix 1.
Mix 2.

22. tile grout
low porosity (low water absorption)
low alkali – (effluoresence , colour fading)
shrinkage compensation
early gelling allows fast and easy cleaning
rapid strength development
reduction of pigments

23. tile adhesive
substrate
tile adhesive

24. wet / dry cycle
substrate

25. loss of strength
substrate

26. natural stone
substrate
mortar bed / tile adhesive
marble stone

27. alkali
substrate
mortar bed / tile adhesive
soluble alkali from mortar bed or adhesive
migrate to the surface dissolving impurities

28. stains
substrate
mortar bed / tile adhesive
stains on surface

29. tile adhesive
Tile Adhesive - white
Mix 1.
Tile Adhesive - white
Mix 2.
OPC white 256 OPC white 256
CAC white 154 CSA white 154
Calcium sulfate 31 Calcium sulfate 51
Sand 513 Sand 493
Cellulose ether 1,9 Cellulose ether 1,9
Polymer powder 40 Polymer powder 40
Accelerator 1 Accelerator 1
Retarder 3,1 Retarder 3,1
Total 1000 Total 1000
open time 45 ~ 60 min.

30. compressive strength MPa
0
5
10
15
20
25
6 hrs 7 days 28 days
Mix 1.
Mix 2.

31. flexural strength MPa
0
1
2
3
4
5
6
7
8
6 hrs. 7 days 28 days
Mix 1.
Mix 2.

32. shrinkage/expansion 28 days
-0,06
-0,05
-0,04
-0,03
-0,02
-0,01
0
Mix 1 Mix 2
Mix 1
Mix 2

33. improved adhesion to substrate
low shrinkage less risk of de-bonding
reduced porosity
low alkaline – (efflorescence)
rapid strength development
reduced porosity and low alkaline
prevent stains on surface marble
tile adhesive

34. decorative SLO
screed
self leveling overlay

35. loss of water
substrate
evaporation
suction substrate

36. curling / debonding
substrate

37. self leveling overlayment
SLO - white
Mix 1.
SLO - white
Mix 2.
OPC white 300 OPC white 300
CAC white 60 CSA white 75
Calcium sulfate 37,5 Calcium sulfate 25
Limestone filler 150 Limestone filler 150
Sand 400 Sand 402,5
PCE 4 PCE 4
Cellulose ether 1 Cellulose ether 1
Polymer powder 40 Polymer powder 40
Accelerator 2 Accelerator 2
Retarder 0,5 Retarder 0,5
Shrinkage compensator 5 Shrinkage compensator
Total 1000 Total 1000

38. compressive strength MPa
0
10
20
30
40
50
60
70
1 day 7 day 28 day
Mix 1.
Mix 2.

39. flexural strength MPa
0
2
4
6
8
10
12
14
16
18
1 day 7 day 28 day
Mix 1.
Mix 2.

40. shrinkage
-0,08
-0,07
-0,06
-0,05
-0,04
-0,03
-0,02
-0,01
0
Mix 1 Mix 2
28 day
Mix 1
Mix 2

41. self leveling overlay
stable base color
easy to pigment
no effluoresence
rapid strength development
high abrasion resistance
shrinkage compensated
short walk-on time

42. CSA WHITE
CSA WHITE proofs to be a good cost effective alternative
acting as cementious binder it features;
lower temperature on hydration
stable white color
fast set
high early strength
no loss of strength in time
reduced shrinkage
elevated bond strength
rapid drying
reduced porosity
no free lime
low alkali

43. whiteness Y
CSA
WHITE
White
Portland
ACA CAC
~85 ~89
~89 ~93

44. glass fiber reinforced concrete
low alkali binder
improves durability glass fibers

45. recycled glass
low alkali allows glass as filler

46. decorative concrete
fast de-moulding prefab elements

47. terrazzo
quick polishing

48. decorative screed / overlayment

49. enviroment
CSA White cement “green binder label” having a ;
decreased amount of limestone reduces release of CO2
(CSA=3CaO·3Al2O3·CaSO4 (36.7%) opposed to OPC=3CaO·SiO2 (73.7%)
lower calcination temperature (~300 °C lower than OPC clinker)
clinker is more friable than other clinker lower grinding cost
possible use of industrial by-products

50. acknowledgements
I would like to express my thanks and gratitude to
Dr.Torsten Kowald and his team at the
Institut für Bau- und Werrkstoff chemie
University of Siegen
and my colleagues at Caltra Lab
for their research and assistance

51. thank you for your kind attention
You are happily invited to visit us at ECS
hall 7 booth 422
and at ECS CONFERENCE
Tomorrow afternoon at 13:30-14:00
“Choosing right Sulphate”