75 Years of experience with high dosed blast furnace slag cement ...

75 Years of experience with high Mario de Rooij 

dosed blast furnace slag cement 

TNO | Innovation for Life 

10-12 November 2010, Holmes Beach, FL, USA

2 

TNO in brief 

The Netherlands Organization for Applied Scientific Research 

• Owner: Dutch Government 

• Mission: 

TNO connects people and knowledge to create innovations that boost 

the sustainable competitiveness of industry and well-being of society 

• 4,400 people p p 

• 576 M€ turn over in 2009; ± 30 % through government funding 

• Active in 7 areas: 

• Safety, y security y and defense 

• Healthy living 

• Energy from solar roads 

• Industrial innovation 

• Energy 

• Investment rather than repair 

• Mobility 

• Binders from municipal waste 

• Built Environment 

• Information society Cement Fly ash Municipal waste 

Slag ash 

75 Years of experience with high dosed blast furnace slag cement 

November 2010, Holmes Beach, FL, USA

3 

Content 

• Slag as product 

• No waste product, but quality control tool 

• Long history 

• Standard for slag 

• Slag as binder material 

• Properties of slag based concrete 

• Low heat of hydration, strength development, freeze-thaw, 

resistance against chloride and ASR 

• Sales and use 

• Conclusions 



4 

What is slag? 

The production process 

Table: Composition range of main 

components in slag (mass %) 

Component Europe NL 

CaO 

SiO2 Al2O3 M O 

30 – 45 

30 – 44 

5 – 16 

4 17 

~ 37 

~ 33 

~ 15 

MgO 4 – 17 ~ 11 

Production: 

100 ton pig iron results in 

20 – 25 ton slagg 


Iron ore, ore 

Coal, 

… 

Pipes for 

11 hot air 

Rapid Skimmer 

granulation 

Slag 

Pig iron 

Molten iron 

and slag 

Fig.: Schematic of a blast furnace 

November 2010, Holmes Beach, FL, USA 

Top filling 

system 

Water 

cooled 

pipes 

Hot 

air

5 

Slag: Not a waste product! 

But a quality control tool 

Quality demand to produce steel: 

Low sulfur content in pig iron (< 00.035%) 035%) 

• Achieved by moving sulfur to the slag 

• Controlled by chemical composition of slag 

CaO MgO 

Alkalinity NL: ~ 1.48 

SiO 

2 

• Slag solidifies sooner than iron 

• Solidification in blast furnace ruins process 

• Controlling liquidus temperature of slag 

• Liquidus q temperature p depends p on CaO, , MgO, g , Al2O 2 3 and SiO 2 

• Same components as first point, but work in opposite direction 

• Blast furnace process is controlled via above two points 



6 

Distinctive blue colour of slag cement 


• A main purpose of slag is to 

remove sulfur (S) from iron 

• In cement reaction the S reacts 

with present Fe and Mg to form 

FeS2 and MgS, both blue 

coloured products 

• Upon reaction with oxygen 

reaction continuous to form 

FFeSO SO4and dMMgSO SO4, which hi h are 

both colourless 


7 

History line 

From slag to binder 

• 384 – 322 BC Aristotle first notes on making and using slag 

• 1728 Patent of John Payne (UK); cast slag to produce blocks to 

build chimneys 

• 1737 Bélidor (France) suggest using slag aggregates in ‘concrete’ 

• 1824 Patent Portland cement by Joseph Aspdin 

Germany: 

• 1853 ‘Discovery’ of latent hydraulic action of slag by a 

German blast furnace process p operator p ( (water cooling) g) 

• 1862 Emil Langen has first results to activate slag 

• 1888 Opening of first blast furnace cement works 

• 1901 Request q for cement standard with up p to 30% slag g 

• 1907 Request for cement standard with up to 85% slag 

• 1909 Cement standard with up to 30% slag 

• 1917 Cement standard with up to 85% slag 

• 1917 Blast furnace-cement has equal q pperformance 

to Portland 

cement 



8 

Slag history in the Netherlands 


• 1921 - 1929Noordersluis IJmuiden using German blast furnace cement 



9 

Locks of IJmuiden 

Building periods 

- 1876 

- 1896 


1921 - 1929 


10 

Typical Mix Design 

Constituents 

Lock head Chamber walls and floors 

Liters Ratio (V/V) Liters Ratio (V/V) 

OPC (CEM ( I) ) 

225 1 

Tras (pozzolanic) 56 ¼ 

GGBFS (CEM III) -- -- 240 1 1/8 

Fine sand 193 0,85 193 0,9 

Coarse sand 387 17 1,7 387 18 1,8 

Gravel 

Water 

- 1896 

700 

?? 

3,1 

?? 

700 

?? 

3,3 

?? 

Northern lock of IJmuiden 

400 x 50 m 

- 1876 


1921 - 1929 


11 

Slag history in the Netherlands 


• 1921 - 1929Noordersluis IJmuiden using German blast furnace cement 

• 1924 Production of steel in Netherlands using blast furnace 

• 1931 Production of first blast furnace slag cement in Netherlands 

IJmuiden (CEMIJ) ( ) 

• 1966 Opening of blast furnace slag cement plant Rozenburg 

(ROBUR) 

• 1970s Blast furnace slag > 50% of cement market in Netherland 

• 1996 IIntroduction t d ti CEM III/A 52,5 52 5 for f faster f t strength t th development 

d l t 



12 

European standard for slag: EN 15167 (2006) 

‘Ground granulated blast furnace slag for use in concrete, mortar and grout’ 

Main requirements: 

Table: Chemical requirements slag Table: Physical requirements slag 

Component Requirement 

CaO + MgO + SiO2 (CaO + MgO)/ SiO2 MgO 

Sulfide 

SSulfate lf t 

LOI 

Moisture content 

2/3 

1.0 

18 % (m/m) 

2.0 % (m/m) 

25%( 2.5 % (m/m) / ) 

3.0 % (m/m) 

1.0 % (m/m) 

Blast furnace controlled on: 

NL: ~ 1.48 


Component Requirement 

Blaine 275 m2 /kg 

Start binding Twice of 

ref cement 

A ti it ffi i t * 

Activity coefficient * 

• 7 days 

• 28 days 

45 % 

70 % 

* Activity coefficient based on 

50% ref cement and 50% slag 


13 

Effect of glass phase 

on strength development (Dölber, 1961) 

3 3 days days (M 

MPa) 

Com mpressive s trength at 

25 

20 

15 

10 

5 

0 

Concrete with 67% slag 

2 

x10 CaO Al2O 

SiO 10 Al O 

2 

3 

3 

1.26 

1.18 

0 20 40 60 80 100 

Gl Glass amount t (%) 

(%) 



14 

Activation of slag reaction 

Two principle routes 

• Increase pH 

• Dependency on 

dissolution 

of the 

glass phase 

• Sulphate 

• Reaction of sulphate p with aluminum fraction to form needle 

structures like ettringite; 

• Build up structure quickly 



15 

Properties: ‘Heat of hydration’ 

Compared to Portland cement low heat of hydration 

Thermal Power P (mW/gg) 

10 

9 

8 

7 

6 

5 

4 

3 

2 

1 

Portland cement 

cement 

Blast furnace slag cement 

0 

0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 


Time (Hour) 


16 

(MPa) 

Norm strength s 

Properties: ‘Strength development’ 

90 

80 

70 

60 

50 

40 

30 

20 

10 

0 

2 days 

28 days 

CEM I 32,5 R 

CEM I 52,5 R 

365 days 

CEM III/B 42,5 N LH HS 

CEM III/A 42,5 42 5 N 

50% slag 

70% slag 

1 10 100 1000 


Time (days) 


17 

A different hardened cement structure 

Portland matrix is less dense than slag matrix 

8 year old C 3S paste; 

w/c = 0.5 

Portland Blast furnace slag 


Pictures credits: I.G. Richardson 

1 year old blast furnace slag 70%; 

w/c = 0.5 


atrix 

Ma 

Chloride 

18 

Dense matrix results in 

High durability of slag cement 

CEM I (Portland cement) CEM III (Blast furnace slag cement) 



19 

Slag effect on chloride ingress 

• Concrete sample kept 1 year in 3 M NaCl bath 

• Next analyzed the slice at 20-40 mm depth 

• Plot total chloride content 


Slice of a core 


20 

Graph from durability performance doc. 

Based on rapid chloride migration data (RCM) 

* 10 /s) 

12 (m 2 / 

DRCM 

40 

30 

20 

10 

CEM I 

CEM III > 50% slag 

OPC, 18-30% fly ash 

fly ash, extrapolated 

0 

030 0.30 035 0.35 040 0.40 045 0.45 050 0.50 055 0.55 060 0.60 065 0.65 


w/b ratio 


21 

Very good ASR resistance 

• The dense microstructure is complement with: 

• A reduced pore size 

• Reduced mobility of the alkalis 

• Using g slag g reduces the total alkalis in the system y 

• There are less alkalis to start with (compared to Portland cement) 

• Creates a lower pH 

• Causes a slower dissolution rate of silica 

• Slag consumes alkalis in the hydration process 

• Making them unavailable for the alkali silica reaction 

• Dutch Department of Transportation / Army corps of engineers (RWS) 

demands use of CEM III/B in all important structures. 



22 

Spalling of slag concrete (freeze/thaw) 

Seems related to carbonation of slag concrete 

• Calcium source: 

• Portland cement reaction with Ca(OH) 2 (volume expansion) 

• Slag cement reaction with Ca from C-S-H (volume reduction) 

• CaCO 3 product p formed: 

• Metastable forms: Stable form: 

Aragonite 

Vaterite 

• In (Dutch) practice 

• Much less damage than in freeze/thaw tests 


Calcite 


23 

Slag in the cement code: EN 197-1 (2000) 

Composition ranges of constituents 

CEM III / B 

CEM III / A 

CEM II / B-T 

CEM II / B-V 

CEM II / B-S 

CEM II / A-V 

CEM II / A-S 

CEM I 

Clinker 

Slag 

Cli Clinker k 

Sl Slag 

Clinker 

Clinker 

Clinker 

Clinker 

Clinker 

Clinker 

Slag 

Slag 

0 20 40 60 80 100 


Slag 

Fly ash (type F) 

Trass 

Clinker 

A: 80 - 94 

B: 65 - 79 

Max. Addition 

A: 6 - 20 

B: 21 - 35 

CEM III (slag) 

A: 36 - 65 

B: 66 - 80 


24 

Cemment 

use in 

NL 

Use of cements in Netherlands 

100% 

90% 

80% 

70% 

60% 

50% 

40% 

30% 

20% 

CEM I 

CEM III 

Fly ash 

• 85% of our ready ready-mix mix is CEM CEM III 

III 

• 40% of our prefab includes CEM III 

10% 

0% 

GGBS as total of cement (%) 

sales in UK 

1975 1985 1995 2005 


Year 


25 

Conclusions 

High dosed slag cement 

• Don’t consider it a waste product 

• Selling a product quality control 

• Properties 

• Low heat of hydration 

• Early strength is much better than generally percieved 

• Creates very dense concrete microstructure 

• GGood d ddurability bilit resistance i t 

• Sales and practice show 

• It is used over many decades 

• In large quantities 

• With great success

75 Years of experience with high dosed blast furnace slag cement ...

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