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

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

White Portlandcement

raw feed ; limestone + kaolin + sand   high energy consumption (~1600°C )

  sintering

  low impurity raw materials

  clinker cooled quickly (water quenching)

  decorative use

main phase composition

C3S alite

C2S belite

C3A tri calcium aluminate

CaSO4 calcium sulfate (≤ 5%)

(added at grinding stage )

hydration

high alkali

fCaO (efflorescence , lime bloom)

shrinkage

long setting time

slow strength development

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

alumina cement

White calcium aluminate cement (CAC)

White calcium sulfo aluminate cement (CSA)

Amorphous calcium aluminate (ACA)

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)

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)

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)

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

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

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

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

tile grout

sub

stra

te

tile adhesive

grout shrinks leaving voids

water enters

sub

stra

te

water penetrating

bond strength reduced

loss of strength adhesive

sub

stra

te

grout falls out

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.

compressive strength MPa

0

5

10

15

20

25

1 day 7 day 28 day

Mix 1.

Mix 2.

flexural strength MPa

0

1

2

3

4

5

6

1 day 7 day 28 day

Mix 1.

Mix 2.

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.

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

tile adhesive

substrate

tile adhesive

wet / dry cycle

substrate

loss of strength

substrate

natural stone

substrate

mortar bed / tile adhesive

marble stone

alkali

substrate

mortar bed / tile adhesive

soluble alkali from mortar bed or adhesive migrate to the surface dissolving impurities

stains

substrate

mortar bed / tile adhesive

stains on surface

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.

compressive strength MPa

0

5

10

15

20

25

6 hrs 7 days 28 days

Mix 1.

Mix 2.

flexural strength MPa

0

1

2

3

4

5

6

7

8

6 hrs. 7 days 28 days

Mix 1.

Mix 2.

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

  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

decorative SLO

screed

self leveling overlay

loss of water

substrate

evaporation

suction substrate

curling / debonding

substrate

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

compressive strength MPa

0

10

20

30

40

50

60

70

1 day 7 day 28 day

Mix 1.

Mix 2.

flexural strength MPa

0

2

4

6

8

10

12

14

16

18

1 day 7 day 28 day

Mix 1.

Mix 2.

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

self leveling overlay

  stable base color   easy to pigment

  no effluoresence

  rapid strength development   high abrasion resistance

  shrinkage compensated

  short walk-on time

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

whiteness Y

CSA WHITE

White Portland

ACA CAC

~85 ~89

~89 ~93

glass fiber reinforced concrete

low alkali binder improves durability glass fibers

recycled glass

low alkali allows glass as filler

decorative concrete

fast de-moulding prefab elements

terrazzo

quick polishing

decorative screed / overlayment

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

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

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”