beremend - 02/2010 christophe denayer milled limestone in concrete

Beremend - 02/2010

Christophe Denayer

Milled limestone in concrete

LIME…The proven solution 2

1. Calcium Carbonate Fines (CCF)

• Milled limestone is CCF if :

Minimum 95% of CaCO3 (calcite, no chalk) Minimum 70% is passing sieve of 63µm Minimum 300 m²/kg Specific Surface Blaine

• CCF will have :

A filler-effect Chemical active as

accelerator


PREMIACAL®

• Calcite is a chemical mineral composed out of natural calcium carbonate (CaCO3) and which is cristallised in a rhomboedric system.


0

20

40

60

80

100

0.1 1 10 100 1000Particle Size (µm)

Cum

ula

tive (

%)

Cement without

limestone

Bosiljkov, Cem Concr Res 33 (2003) 1279-1286

1

2

3

12

3

Cement & CCF

CementCCF

CCF has a filler-effect


CCF influences the initial and final setting of cement

• Initial and final set are reduced.

• CCF is an activator of the hydration

Hawkins et al, PCA report (2003)

1:12

2:09

3:07

4:04

5:02

6:00

0 2 5 8Limestone content (wt. % )

Sett

ing z

one (

hour)

Initial set

Final set

Cement with

limestone filler


Rate of heat release of the pastes

• The rate of heat release in a mixture with CCF, is influenced during the first 10 hours.


What happens chemically during cement hydration ?

• Calcium aluminate hydration- without gypsum

- with gypsum (Portland cement) : 2 stepsC-A-H (‘Flash Set’)C3A + H2O

(1) C3A+ H2O + CSH2 C6AS3H32 (Ettringite)

C4ASH12 (Monosulfate)C3A + C6AS3H32(2)

• Calcium aluminate hydration- without gypsum

- with gypsum (Portland cement) : 2 stepsC-A-H (‘Flash Set’)C3A + H2O

(1) C3A+ H2O + CSH2 C6AS3H32 (Ettringite)

C4ASH12 (Monosulfate)C3A + C6AS3H32(2)

C-A-H (‘Flash Set’)C3A + H2O C-A-H (‘Flash Set’)C3A + H2O

(1) C3A+ H2O + CSH2 C6AS3H32 (Ettringite)(1) C3A+ H2O + CSH2 C6AS3H32 (Ettringite)C3A+ H2O + CSH2 C6AS3H32 (Ettringite)

C4ASH12 (Monosulfate)C3A + C6AS3H32(2) C4ASH12 (Monosulfate)C3A + C6AS3H32(2)

+ CaCO3 C3A.CaCO3.xH2O(Carboaluminate)

(1’)

+ 3 new routes

+ CaCO3 C3A.CaCO3.xH2O(Carboaluminate)

(1’)+ CaCO3 C3A.CaCO3.xH2O

(Carboaluminate)+ CaCO3 C3A.CaCO3.xH2O

(Carboaluminate)C3A.CaCO3.xH2O(Carboaluminate)

(1’)

+ 3 new routes

+ CaCO3

C3A.CaCO3.xH2O (Carboaluminate)

(2’)+ CaCO3

C3A.CaCO3.xH2O (Carboaluminate)

(2’)

C3A10%

C4AF10%

CSH2

5%C3S

50%

C2S25%

C3A

C-S-H

C3A


2. CCF for all types of concrete.

SCC

PAVING BLOCKSSTAIRS

PILLAR & BEAMS

Ready Mix Concrete

Semi-dry concrete

SCC-precast

Ready-mix concrete


3. semi-dry concrete

PAVING BLOCKSPIPESHOLLOWCORE FLOOR SLABS ROOF TILES

cement

water

cement

hydrates + free CaO

immediate after some H

after some D

setting of cement

network of cristals

• Cement is acting as a « filler ».

Replacement of 10 to 35%

of cement

• The most important targets for us in the concrete market are the producers of :


Example : mix-design for paving blocks

• Conclusion : Substitution of 51 kg of cement (261/50 -> approx. 20%) result in

costsavings of 600 HUF/m³ Maximum is 30 to 35% of cementreplacing -> 1200 HUF/m³

Price CEM I HUF/T 18000Price CCF HUF/T 6000

Mixture [unit] A B Ccement kg/m³ 311 261 211water l/m³ 109 109 109w/c 0,35 0,42 0,52CCF kg/m³ 50 1000/4 kg/m³ 867 867 8674/8 kg/m³ 1103 1103 1103

Price CEM+CCF/m³ HUF/m³ 5598 4998 4398Cost savings HUF/m³ 600 1200


Architectural reasons : less efflorescence & brighter

with CCF

without CCF

CCFCEM I

• Less risk on efflorescence, because of lower content of cement in mix-design


What in case of sulfate environment ?

• Respect miminum content of cement of EN 206 (XS-classes, …)

• Additional fines needed (=cement)? Replace cement with CCF


4. Ready-mix concrete

STAIRS

Ready Mix Concrete

Concrete screedCCFCEM I


French method : k-value = 0,25 (EN 206)

Among NF-EN 206

X0 XC1 XC2 XC3 XC4 XS1 XS2 XS3 XD1 XD2 XD3 XF1 XF2 XF3 XF4min. w / binder equivalent 0,65 0,65 0,60 0,60 0,55 0,55 0,50 0,60 0,55 0,50 0,60 0,55 0,55 0,45min. res. classe C 20/25 C 20/25 C 25/30 C 25/30 C 30/37 C 30/37 C 35/45 C 25/30 C 30/37 C 35/45 C 25/30 C 25/30 C 30/37 C 30/37min. equivalent binder 150 260 (*) 260 (*) 280 (*) 280 (*) 330 330 350 280 330 350 280 (*) 300 315 340min. % of air - - - - - - - - - - 4 4 4A/(A+C) 0,25 0,25 0,25 0,25 0,25 0,05 0,05 0,05 0,25 0,05 0,05 0,25 0,25 0,25 0,25

(*) 300 kg/m³ prestressed concreteA/(A+C) min eq bi A max C eq C min

unity kg/m³ kg/m³ kg/m³ kg/m³0,25 280 93 23 2570,05 330 17 4 326

280 257

93

0

50

100

150

200

250

300

350

400

1 2


5. Self compacting concrete (SCC)

1200835

675

820

350

350

250

175 175

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

conventional SCC

Water

Fillers

Cement

Sand

Aggregates

SCC

• Need for fillers in SCC

• MLS disposes a constant water-absorption, colour, …


Mix design of Okamura & Ouchi, corrected by NL

SCC mix-design in 9 steps :1. volume of air2. volume of coarse aggregates3. volume of fine aggregates4. volume of paste5. ratio w/p6. testing on mortar bars 7. testing on concrete8. calculation9. controlling


Vair -> V coarse aggr -> Vfine aggr -> V paste

• Assume : Vair = 2% or 0,020 m³ -> ➊

• Assume : 50% of rest-volume is used by coarse aggregates at their best stacked pile V coarse aggr = 0,5.(1-Vair).ρb / ρa (in m³) -> ➋

ρa = 2650 kg/m³ (specific weight of aggregates)

ρb = 1670 kg/m³ (best stacked weight of aggregates)

Remark : if 45%, use 0,45 in formula

• Assume : V fine aggr = 0,45 (1 - V coarse aggr - Vair)

We are reducing the quantity of fine aggregates to garantee that the influence of the fluidity of the paste will also be applicable on the mortar. [Assume 0,45 – could also be 0,40]

• V paste = 1 - V coarse aggr – Vfine aggr – Vair


powder

water

V

V

12

0

d

d

p

How to determine beta P of a powder

• Cement -> 0,9 till 1,4

• Milled limestone -> 0,8d

dd

2

21

2


w/p-ratio

• Water-powder ratio : Paste = powder + water

Powder = cement + addition• βp cement = 1,2 (CEM I 52,5 R)

• βp addition = 0,8 (milled limestone)• Assume relation cement/addition: 60/40 in volume• βp cement+addition = (0,6 x 1,2)+ (0,4 x 0,8) = 1,04

Water : w/c-ratio : (1,04 x 1,0)/(0,6 x 3,15) = 0,55

• Correction-factor for waterdemand of powder : – CWm (between 0,7 and 1,0) -> assume 0,85 (not definitif)

w/p-ratio = Vw/Vp = CWm. βp cement+addition = 0,884 -> ➎

1,2 liter water is needed for 1 liter of cement :

So 1,2 lw / 1,0 lc = (1,2x1,0) / (1,0x3,15) = 0,38

w/c-ratio without flow

1,04 liter water is needed for 1 liter of C+A :

So 1,04 lw / 0,6 lc = (1,04x1,0) / (0,6x3,15) = 0,55

to reduce the risk for segregation


Mortar mix-design (1)

• Mortar consist of Cement Addition Sand Water Admixtures No coarse aggregates

• Define 1500 ml of mortar : Assume : 45% or 675 ml = absolute volume of

sand So, 55% or 825 ml = paste



We know from earlier :• Beta p (C+A) = 1,04• CWm = 0,85• Vw/Vp = CWm. βp cement+addition = 0,884

Assume : • 45 % of mortar = sand -> 1500 ml x 0,45 = 675 ml• Ratio (Cement/Addition) = 60/40

Solution :• Vpaste = 1500 – 675 = 825 ml• Vw / Vp = Beta p (C+A) x CWm = 1,04 x 0,85 = 0,884• Vp = Vpaste /(1 + Vw / Vp) = 825 / (1+0,884) = 438 ml

Vcement = 0,6 x 438 = 263 ml Vaddition = 0,4 x 438 = 175 ml

• Vw = Vpaste – Vp = 387 ml

• We are looking for a just combination between

– watercontent (Vw / Vp) – admixtures (%)

s

% of admixtures [on powder content]

V density weightml T/m³ g

sand 675 2,65 1.789water 387 1 387cement 263 3,15 828milled limestone 175 2,17 380Total 1500 3.384

Mortar funnel test [s]

Mortar flow test [mm]



320

330

340

350

360

370

380

390

0 2 4 6 8 10 12

OK

[mm] – mortar flow test

1. Not OK, correct with– Raising admixtures : flow

(mm) will raise (a)– Raising CWm : more water in

mixture, less viscosity, less time (s) for empty the funnel. (b)

2. Not OK, correct with sand-ratio :

– Raising sand% : lower flow (mm) and higher time (s)

3. Other : – Change admixtures– Change cement/addition-

ratio– Change coarse aggregates

volume

4. Conclusion : we know CWm – % admixtures

– Vw – Vc- Va - Vfine aggr

[s] – mortar funnel test

a

b

Not OK, we can correct formula with1. Reducing/raising admixtures2. Correct CWm (reducing or raising)3. Other sand %4. Other changes

% of admixtures

7 s 11s


Concrete mix-design (1)

Coarse aggregates

Mortar :1. Fine aggregates

2. Paste = water + powder

• Vair = 2% or 0,020 m³ -> ➊

• Assume : 50% of rest-volume is used by coarse aggregates at their best stacked pile

– V coarse aggr = 0,5.(1-Vair).ρb / ρa (in m³) -> ➋

– ρa = 2650 kg/m³ (specific weight of aggregates)

– ρb = 1670 kg/m³ (best stacked weight of aggregates)

– Remark : if 45%, use 0,45 in formula

Abrams cone

V-funnel


Concrete mix-design (2)

Results in function of application :

Flow (mm) Time (s)

Wall 830 7

Pillar 780 8

Beam 780 8

Floor 720 11

If not OK :corrections with % admixt. and/or water (CWm)

Conclusion :

1. V paste = 1 - V coarse aggr – Vfine aggr ➌ – Vair -> ➍2. % admixtures

3. Final correction factor CWm

type0-4 0-8 0-16 0-32

A 270 390 515 600B 240 350 450 515C 60 105 150 195D 30 40 65 85E 30 40 75 95

(liters) 1,13 3,27 10,51 18,3

size aggregatesdimensions V-funnel in mm

Abrams cone

V-funnel


Calculation & controling

1. % of admixtures is defined (after concrete tests)

2. CWm is now defined (after concrete tests)

3. V coarse aggr & Vfine aggr & Vair are also known : ➊ ➋ ➌

4. V paste = 1 - V coarse aggr – Vfine aggr – Vair -> ➍

5. Vpowder = V paste / (1+Vw/Vp)

1. with Vw/Vp = CWm. βp cement+addition

6. Vw = V paste - Vp

7. Powder = cement + addition and the ratio C/A is known -> we can count the quantity of each powder

Do we respect EN 206 ? w/c ratio ? minimum content of cement for the environmental class


What you need in each laboratory is …

V-funnel

type0-4 0-8 0-16 0-32

A 270 390 515 600B 240 350 450 515C 60 105 150 195D 30 40 65 85E 30 40 75 95

(liters) 1,13 3,27 10,51 18,3

size aggregatesdimensions V-funnel in mm

Cone of Haegermann

Cone of Abrams

V-funnel for mortar test

V-funnel for concrete test


Other testmethods to characterize fresh SCC

• U-box

• L-box

• J-Ring

• Stability on sieve

• Orimet

U-box

Stability on sieve

J-ring

L-box

Orimet


SCC - applications

BEAMS

COLUMS - PILLARS

STAIRS

WALLS

Ready Mix Concrete

• PRECAST CONCRETE. Typical applications :

• READY-MIX CONCRETE .


Ask assistance by your superplasticizer-supplier

• MAPEI

• BASF : SP = glenium® (before Degussa, before Masterbuilders)

• SIKA : SP = viscocrete®

• CHRYSO : SP = premia®

Do not forget :

SCC is technically feasible due to the latest development of polycarboxylates


6. Carmeuse Europe supplies to 400 concrete plants

• 370 concrete plants in W-Europe (France, Belgium, NL)

• 30 concrete plants in Central Europe (CZ) :

1. HOLCIM CZ (ready-mix concrete : SCC, screed, architectural,..)

2. RIEDER BETON (SCC-pillar&beams)

3. DYWIDAG (SCC-pillar&beams)

4. ZPSV (SCC-pillar&beams)

5. Prefa Brno (paving blocks, pipes,…)

• HU : first clients


7. Scientific Review of MLS in concrete


•Thank you

beremend - 02/2010 christophe denayer milled limestone in concrete

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