03 Quality

Table of Contents

1. Chemical Characterization... 3.1 1.1 Ignition Loss ... 3.1 1.2 Silica Ratio... 3.1 1.3 Alumina-Iron Ratio ... 3.1 1.4 Lime Saturation... 3.1 1.5 Total Alkalies as Na2O ... 3.1 1.6 Percent Liquid ... 3.2 1.7 Bogue Formulas ... 3.2 1.8 Lafarge K 1450 Burnability Index... 3.2 1.9 Other Indicators... 3.4 1.10 57 Clinker Average... 3.4 2. Particles Size Distribution... 3.5 2.1 Rosin-Rammler Number... 3.5 2.2 Specific Surface Area ... 3.5 2.3 Blaine Surface Area... 3.6 3. Grindability... 3.6 3.1 BB10 Test ... 3.6 3.2 Bond Formula ... 3.7 3.3 Parameters Affecting the Clinker Grindability... 3.7 4. Sulfate... 3.8 4.1 Clinker Sulfates ... 3.8 4.2 Sulfate Addition ... 3.8 4.3 Water Spray ... 3.10 5. Others Quality Issues... 3.10 5.1 Cement Strength... 3.10 5.2 Color ... 3.10 5.3 Microscopy ... 3.11 6. 10 Basic Facts on Clinker... 3.12 7. Raw Mix & Clinker Uniformity ... 3.13 7.1 TYTP Indicators... 3.13 7.2 Lafarge Corp Results ... 3.13 8. ASTM Standards ... 3.14

1. Chemical Characterization

• In the following formulas:

S = SiO2, M = MgO, A =Al2O3, K = K2O, F = Fe2O3, N = Na2O3, C = CaO

when not specified: % is in weight in the raw mix.

• Raw feed density: 2700g/l.

1.1 Ignition Loss

• Ignition loss = 0.786 * C + 1.092M + combined H2O+ organic matter.

• CaCO3 →CaO+CO2 - %CaO 56 44 CO % ₂= × 1.2 Silica Ratio •

(

2.3 to 3.1

)

F A S SR + =

- If SR high, hard to burn, low coating (wall losses), poor clinker reactivity, higher SHC.

1.3 Alumina-Iron Ratio •

(

1.3to 2.0

)

F A AR =

- If AR high with low F then lower liquid phase, poor viscosity.

1.4 Lime Saturation

(On Raw Mix analyses, except C3S)

• C₃S =4.07C−

(

7.6Ssol+6.72A+1.43F

)

- _{It is the potential C3S content of clinker}

when the free lime is zero and calculation LOI=0.

- It is the only lime saturation criterion considered in the TYTP.

• F 65 . 0 A 18 . 1 S 8 . 2 C 100 LSF + + = • C F A S ) C F 3 . 0 A 65 . 1 S 8 . 2 ( * 100 bc _{+ + +} − + + = ∆

- It should range between –4 and +4 depending on ashes and quality target.

• F 7 . 0 A 1 . 1 S 8 . 2 C 100 ) Kuhl ( KSt_I + + = where: - A includes (TiO₂ +P₂O₅ ) • F 65 . 0 A 18 . 1 S 8 . 2 ) M 75 . 0 C ( * 100 KSt_III + + + =

- It takes MgO into account (when MgO < 2%). LSF vs C3S y = 0.3367x + 71.6 R2= 0.9485 60 70 80 90 100 110 120 0 20 40 60 80 100 120 C3S LS F ∆bc vs C3S y = -0.2734x + 21.552 R2= 0.9606 -20 -15 -10 -5 0 5 10 15 20 25 30 0 20 40 60 80 100 120 C3S ∆∆∆∆ bc ∆∆∆∆ 1.5 Total Alkalies as Na2O • Total as Na₂O eq = Na₂O+0.658K₂O Rule of thumb

• + 0.1% Total Alkalies in clinker : -0.5 to -1MPa at 28days.

1.6 Percent Liquid

a) Calculation (Lea & Parker)

@ 1338ºC • A/F<1.38:

K

N

M

F

A

liquid

=

8

.

2

−

5

.

22

+

+

+

%

• A/F>1.38 : K N M F 1 . 6 liquid % = + + +

• PL at 1338C influences the clinker granulation. @ 1400ºC

• % liquid =2.95A+2.25F+M +N+K @ 1450ºC

• % liquid =3A+2.25 F +M +N +K

• 1450 C is most frequently used within Lafarge.

• Optimum at 1450C: 25%. @ 1470 ºC

• % liquid=1.13C₃A+1.35 C₄AF+M+N+K b) Liquid phase impact

• If liquid phase too high: - Clinker porosity↓↓↓↓ - Grindability↓↓↓↓(harder) - 1-day strength↓↓↓↓

• If liquid phase too low:

- _{C3S formation speed}↓↓↓↓ - Clinker granulation↓↓↓↓ Liquid Phase Constituent Impact

C3A C4AF K2O 0 2 4 6 8 10 12 14 1250 1300 1350 1400 1450 1500 1550 temperature °C 18 % 5 % 1 % 5 % 18 % 1 % 5 % 18 % 0 % 18 % 5 % 0 % % free CAO 1.7 Bogue Formulas

(On clinker bases, ref. Les Cahiers Techniques). The formulas considered in the TYTP are:

a) Formulas • C₃S =4.07C−

(

7.6Ssol+6.72A+1.43F

)

• C₂S=8.6Ssol5.07A+1.08F−3.07C1 • C₃A=2.65A−1.69F • C₄AF=3.04F with:

- C1=CaO−FreeCaO−(0.7SO₃) - Ssol= soluble silica (silicate form only) - AndF may be modified as:

3 2 3 2O Mn O Fe F = − b) SO3 combination Step #1: • If 3 2 SO O K

< 1.176 not all SO₃ combined as

4 2SO K then SO₃inK₂SO₄ =0.85K₂O Step #2: • Remaining SO₃=SO₃−SO₃inK₂SO₄ • If ) remaining ( SO O Na 3 2 _{< 1.176 not all} 3 SO combined as Na₂SO₄: O Na 292 . 1 SO Na in SO_{3 s 4} = ₂ Step #3:

• CaO combined with SO₃

(

)

(

SO3 SO3inK2SO4 SO3inNa2SO4

)

* 7 . 0 − + =

1.8 Lafarge K 1450 Burnability Index

a) Calculation

This index is representative of the ability of the raw material to combine. The sample is heated (1000ºC/h) in a lab furnace at 1450 ºC for 30 minutes. After burning, the remaining free lime is measured. The ability to combine is determined by the reaction time of the following reaction:

S C C S

If we accept that this reaction can occur only after all C₂S is formed: 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 -8 -6 -4 -2 0 2 4 6 8 200 180 160 140 120 100 80 60 40 20 00 00 00 00 00 00 00 00 00 0 0 0 0 0 0 0 0 0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0 0 0 0 0 0 0 0 0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Lafarge K H e a t c ons um pt ion dif fe re nc e (% ) • k

[

C S

] [ ]

C dt ] C [ d 2 • = with: - [_{C2S] is the}

C

₂

S

concentration at t - [C] is the lime concentration at t - k is a constant (function of temp).

•

[ ]

[ ]

[ ]

[

]

172 S C S C 56 C Co ₂ o − ₂ = − with:

- [C°] is the concentration of lime at t_º - [_{C2S°] is the concentration of C2S at tº} •

[ ]

[ ]

172

56

2

S

C

C

c

=

∆

+

with:

∆

c is the

∆

_bc relative at 100% clinker:

•      

−

+

+

+

∆

=

∆

LOI

C

F

A

S

bc c

100

.

•

[ ]

[ ]

_{[ ]}









∆ + ∆ + ∆ = C C C C K o c o c cln . 07 . 3 1 with: - [Co] = CaO - 1.87 SiO2

- [C] = The remaining free lime in a lab test in which the raw material is burned for 30 minutes at 1450ºC

Rule of thumb

K < 30: Very bad burnability 30 < K < 45: Bad burnability 45 < K < 70: Medium burnability 70 < K < 100: Good burnability

100 < K < 140: Very good burnability 140 < K: Excellent burnability

b) Parameters influencing the Burnability (ref. Cahiers techniques)

-80 -40 0 40 +0.1 % fluor +0.4 % sol. Na2O equiv. +1 % Ex.SO3 +1.3 % Fe2O3 +0.2 % P2O5 +3 % quartz > 63 µ K1450 change Rules of thumb

• K2SO4 improves the burnability;

• +1% SO₃ lower the combination temperature by 60C;

• +1% K₂O increases the combination

temperature bu 35C;

• increase from 2 to 3% of silica reject at 63 microns lower the K1450 by 30 points (cf graph);

• + 0.3% CaF2 addition in the raw mix (or 0.23F in the clinker) improves the K1450 by 10 to 60 points, lowering the burning temp by 30 to 130C. Unfortunately, it lengers the setting time by 40min +/-20min (for+0.1%F in the clinker). Impact of fineness • Free Lime =

[ ]

C −1.89+0.48

(

LSF −100

)

+

(

SR 1.8

)

0.27Q45 0.12C125 0.12Aq45 84 . 2 − + + + where: - Q₄₅ = % quartz >45µm - C₁₂₅ = % calcite >125µm

- Aq₄₅ = % non quartz, acid insoluble >45

µm (excluding dolomite) Rule of thumb:

0 1 2 3 4 5 6 1350 1400 1450 1500 1550 Effects of % 100 µm rejects Marl type raw mix % free CaO temperature °C 25 % 10 % 0 1 2 3 4 5 6 1350 1400 1450 1500 1550 Effects of % 100 µm rejects Quartz type raw mix % free CaO temperature °C 25 % 10 % 5 % 1.9 Other Indicators Burnability Factor • A C AF C S C BF 3 4 3 + =

- HigherBF, harder to burn - GenerallyBF increases with SR

Hydraulic Module • M C F A S HM + + + = Cementation Index • M 4 . 1 C F 7 . 0 A 1 . 1 S 8 . 2 Cl + + + = 1.10 57 Clinker Average

• The results obtained from 57 production clinkers including 2 white cements and 4 Oil-Well cements are reported below:

Raw Mix S/(A+F) S/(A+F) A/F A/F Liq. phase ∆nc Free CaO K 1450 Exc. HTS, SB Exc. OW, SB At 1450° % % Minimum 21 2.1 2.1 0.6 0.7 10.5 -0.8 0.05 Average 75 2.9 2.7 2.0 1.7 24.0 5.3 0.68 Maximum 324 7.8 3.6 11.6 2.9 29.4 10.2 2.2

C3S Alite Alite/C3S C2S Belite Belite/C2S C3A Alum.

% % % % % %

Minimum 43.0 45.6 0.9 1.9 0.7 0.15 0.0 0.7 Average 61.9 66.0 1.07 15.7 15.0 0.93 7.6 5.2 Maximum 75.9 81.1 1.4 31.5 35.0 1.91 12.6 11.0

C4AF Ferrit. MgO Fluor TiO2 P2O5 Mn2O3 kk SO3

% % % % % % % %

Minimum 0.8 0.0 0.39 0.02 0.10 0.01 0.01 0.2 Average 9.3 8.9 1.80S 0.08 0.23 0.12 0.06 0.84 Maximum 16.8 15.0 4.53 0.19 0.39 0.39 0.19 2.5

Total Na2O Sol. Na2O Total K2O Sol. K2O Tot.Na2O eq Sol.Na2O eq Exc.SO3 Exc.SO3

% % % % % % /t. alk. % /s. alk. % Minimum 0.06 0.01 0.25 0.11 0.27 0.08 -0.63 -0.16 Average 0.17 0.07 0.74 0.54 0.66 0.43 -0.01 0.29 Maximum 0.40 0.19 1.40 1.19 1.00 0.87 1.73 1.86

2. Particles Size Distribution

2.1 Rosin-Rammler Number

• The Rosin-Rammler curve mathematically approximates most powder particle size distributions:

n o d d e 100 R       − = or n _            R 100 ln = n

(

In(d)−In(d_o)

)

- d = particle size (µm) - R = % retained at d

- do = particle size (µm) @ R = 100/e, approx. 36.8%

- n = Rosin-Rammler number

• The formula allows PSD data to be represented as a straight line by plotting: (In (In

R

100_{)) vs. In (d)}

- n can be calculated by the slope of the least squares line.

- The higher the RR#, the steeper the PSD as more particles are found into a narrow size range.

Rules of thumb

• RR# for high efficiency separator cement: 1.1 - 1.2 - RR# for Sturtevant circuit (raw or cement): 0.9 - 1.0 - RR# for open circuit cement: 0.8 - 0.9,

• dO= 12-36µm

• + 0.15 point #RR increases the water demand by 2-3% (ref. Les Cahiers Techniques)

2.2 Specific Surface Area

• The following can calculate the Specific Surface Area (SSA). For particles assumed to be spheres:

• 2 i i 4 r S = π r p 3 4 M_i= π _i3 - S_i = the particle surface area

- M_i = the particle weight - r_i = the particle radius

-

ρ

= the specific density of particles

• For a granulometry withn number of particles

Str = ni * Si = ni * 4πri2 Mtr = ni *

π

ri3

ρ

3 4

ρ

∗

∗

=

i tr tr r M 3 S

•

∑

= + + + − = 16 0 1 1 6 j j j j j d d R R f SSA

ρ

- f = Form factor (close to 1)

-

ρ

= Specific density of cement (g/cm3) - Ri = % retained atdi - _{di =} Particle size (µm) do = 0.1µm _{d6 = 4}µm _{d12= 48}µm d1 = 0.3µm _{d7 = 6}µm _{d13 = 64}µm d2 = 1µm _{d8 = 8}µm _{d14 = 96}µm d3 = 1.5µm _{d9 = 12}µm _{d15 = 128}µm d4 = 2µm _{d10 = 16}µm _{d16 = 196}µm d5 = 3µm _{d11 = 24}µm

• The 0-3µm fraction of normal Portland cement accounts for 60% of total surface.

2.3 Blaine Surface Area

• SSB = Blaine Surface Area (in cm2/g). It’s a permeability test. SSB is inversely proportional to the ability to pass air through a bed of particles. The correlation between calculated SSA and SSB is:

SSA = 807 + 1.2 * SSB

• For cements with n=1 Anselm found:

ρ * n * do * 8 . 36 SSA 104 = where:

- do, n Rosin-Rammler distribution - ρ = specific density = 3.2 x103kg/m3 Rules of thumb (Les Cahiers Techniques)

• The Blaine specific surface correlates well (r2 = 0.92) with the % passing 10 µm (same for 8 µm): + 1 % passing 10 µm = + 10.8 m2/kg

• + 100 m2/kg SSB
+4 to + 15 MPa (pure cements).

Warning: Cement sulphate addition must be increased with SSB: +100 m2/kg
+ 0.5 to +0.6% SO3.

• 2% gypsum results in +10m2/kg at 370m2/kg SSB.

3. Grindability

3.1 BB10 Test

Idea:

• Correlate the number of revolutions of a lab mill for a given fineness with the industrial energy to obtain the same fineness. The material is crushed to everythingpassing 3.15 mm. The number of mill revolutions is measured to obtain a given fineness. Revolutions are converted to industrial power consumption.

Lab Mill Characteristics: Diameter: 40 cm

Length: 12 cm Speed: 55 rpm

Ball volume load: 14 % Ball weight: 10 kg

Material load: 1kg Balls: 20-25 mm : 2.5 kg 20-35 mm : 3 kg

Lafarge Data

• 25 Canadian clinkers @ 3500 Blaine averaged 55.7 kWh/t and 35 French averaged 50.7 kWh/t. Typical results are 48-60 kWh/t.

BB10

kWh/t for 250 m2/kg_kWh/t for 300 m2/kg_kWh/t for 350 m2/kg_kWh/t for 400 m2/kg_kWh/t

Minimum 21 30 39 49

Average 29.2 39.8 51.8 65.3

Maximum 43 56 68 83

3.2 Bond Formula

Lab Mill Characteristics Diameter: 30.5 cm Length: 30.5 cm Ball weight: 20 kg Material quantity: 700 cm3 Speed: 70 rpm Formula         − • = 80 f 80 p 0.82 23 . 0 100 p d 10 d 10 * P d 5 . 44

Wi dp100 is the sieve with 100% passing feed material

dp80 80% feed material

df80 80% finish material

P is the production (g/rev of mill) of product at the level the circulating load is requested.

Wi is the Bond work index.

• Developed to predict energy requirements of 2.44m diameter, wet, closed circuit, ball mill at a fineness of either 65 mesh (220 µm) or 100 mesh(150 µ m).

• Pre-crush feed to #6 (3.35 mm). Maintain 700g sample in test mill. Turn mill 100-150 rev.

• Remove undersize (dp100 – 65 or 100 mesh) and replace with fresh feed (300 – 400 g). 1st cycle is now completed. Repeat procedure until steady state is reached. Typically 6-8 cycles so that 200 g are removed at each cycle, which equals 250% circulating load or 30% of “P”.

3.3 Parameters Affecting the Clinker Grindability

• In the statistical study of the 57 clinkers, grinding energy was correlated with different parameters. 1 point increase of
produces

a variation of C3S Exc SO3 /tot.alk. (%)

CaOl (%) D75 alite (µm) Alite C3S_x100 W250 (kWh/t) -0.3 4 -0.9 0.1 W300 -0.5 4 0.1 -0.1 W350 -0.6 5 0.2 -0.2 W400 -0.7 5 0.2 -0.3

4. Sulfate

4.1 Clinker Sulfates

• Possible forms of sulfates and alkalies:

- as alkali sulfates (small crystals of a few µm) inserted between the clinker phases - as S and alkalies inserted in the crystal structures of silicate and aluminate phases

Clinker rich in alkalies and…

… poor in sulfates … rich in sulfates

• Little alkali sulfates

• Uncombined alkalies:

- N and K in orthorhombicC3A

- K inC2S

• Inversed monoclinicC3S

• Much alkali sulfates

• Little uncombined alkalies: - Little K and N in cubicC3A

- Little K inC2S • RhomboedricC3S

• Some sulfur in the uncombined alkalies

alkali sulfates alkali sulfates S in silicates and aluminates Workability problems, plastic shrinkage Increase of early-age strengths Clinker harder to grind N and K in C3A orthorhombic C3A orthorhombic

Clinker sulfate content

Cubic C₃A

Cubic C₃A Cubic C₃A

alkali sulfates

• On the basis of the content of sulfur with respect to alkalies, and the relative proportions of sodium and potassium, alkali sulfates may be found under different forms:

- Thenardite : Na₂SO₄. This sodium sulfate is rarely seen in clinker.

- Aphthitalite : Na₂SO₄ 3K₂SO₄. Its composition may vary to

(

3Na₂SO₄ K₂SO₄

)

. - Arcanite : K₂SO₄. It is observed when the SO₃ /K₂O molar ratio ranges between 1 and 2.

- Calcium langbeinite: 2 CaSO₄ K₂SO₄. This phase is encountered when the SO₃ / sodium equivalent* molar ratio is greater than 2 and the sodium percentage low vis-à-vis potassium.

- Anhydrite:CaSO . It shows up only when the₄ SO₃ / sodium equivalent* molar ratio is greater than 3.

4.2 Sulfate Addition

• Gypsum and/or anhydrite - sulfates are added to control the setting process of the cement, primarily the rapid setting of the C3A component.

a) False set:

• Early development of stiffness without the evolution of much heat. It can be dispelled and plasticity regained by further mixing without the addition of water [also called "grap set", "premature stiffening", "hesitation set", "rubber set"].

b) Flash set:

• Early development of stiffness usually with considerable evolution of heat. It cannot be dispelled nor plasticity regained by further mixing without adding water [also called "quick set"]. Reaction is:

(

H O

)

n A C C O nH A C₃ + ₂ + → _{4 2} .

c) The Chemistry of False and Flash Set Components

• Hemihydrate and the anhydrites are the dehydrated forms of gypsum.

- Gypsum CaSO₄ .2H₂O

-

β

-hemihydrate (plaster of Paris) CaSO₄ .0.5H₂O

- Soluble anhydrite (CaSO .III)₄ CaSO₄ .(0.001_0.5)H₂O - Insoluble (natural) anhydrite CaSO₄

• They react differently than gypsum when added to cement. Reactions S O 3 s ol uti on (g /l) 0 0. 1 1.5 2 2.5 3 3.5 4 4.5 1 2. 6 1 2 3 Gypsum Hemihydrate Soluble Anhydrite Natural Anhydrite Sulfate solubility Time - Minutes 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 00 00 00 00 00 00 00 00 00 00 0 0 0 0 0 0 0 0 0 0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 180 160 140 120 100 80 60 0 20 40 60 80 100 Temp. °C % Dehydr.

• Dehydration in the milling process can be thought as beginning at about 80 °C. However, gypsum dehydration is also a function of the time and % humidity of the surrounding atmosphere. Hemihydrate reacts differently than gypsum or anhydrite when water is added to cement, due to the differences in solubility. In the case of too much hemihydrate, which dissolves very quickly and in substantial quantities in the mix water, false set will occur. While too much hemihydrate will cause false set, not having enough SO3 available in solution will cause much more serious flash set.

• The following table gives schematic diagrams of the structure development of cement. The lattice work represents the ettringite crystallization, the platelets - tabular monosulphate and the rectangles - secondary gypsum.

Available sulphate in

solution

Hydration time 10 min 1 hour 3 hours

Type of set Low C3A Low SO3

workable workable set

High C3A

High SO3

workable set set

Low C3A High C3A Low SO3 High SO3 Flash set False set

set set set

set set set

Accelerated set Normal

Optimum sulfate

• S=1.2

(

%solNa₂O equiv.

)

+0.2

(

%Al₂O₃

)

+6.2 10−3

(

BSS

)

− 0.7.

• The sulfate content roughly corresponds to the optimum for 3-day strengths.

4.3 Water Spray

• One method to control the mill temperature and thus gypsum dehydration is through the use of water spray. For reasons of cement quality (_{C3S hydration), the water vapor dew-point temperature in the mill air must} not exceed about 70 °C. The decomposition enthalpy of crystalline water in gypsum is much less (628 kJ/kg) than the evaporation enthalpy of water (2257 kJ/kg).

• Thus theoretically one can:

- Reduce Preliminary Hydration - use anhydrite (no crystalline water) instead of gypsum and keep the water spray constant. This will decrease the water content of the air. The mill outlet temperature will increase in this case.

- Reduce The Mill Outlet Temperature - use anhydrite and increase the water spray, keeping the dew-point constant. The preliminary hydration will remain the same because the water content of the air remains constant.

- Reduce Temperature and Preliminary Hydration - use anhydrite and substitute some, but not all, of the crystalline water for more water spray.

5. Others Quality Issues

5.1 Cement Strength

• Theoretical water required to totally hydrate the cement: 35% weight of cement. Warning: Here, MPa are French standard (1.45 French MPa= 1 US/Can MPa) Parameters influencing the cement strength

A variation of? Mpa Strength
is produced by an increase of 1 point of:

Sol Na2Eq (%) Tot Na2Eq (%) C3S (%) C2S(%) C3A (%) C4AF (%) MgO (%) SO3/totAlk Excess FcaO (%) D75Belite (µm) 1-d fc (MPa) 10 0.1 0.5 -1.1 1.1 1.1 -0.2 2-dfc (MPa) 10 0.3 0.3 -1.0 1.3 -0.2 7-d fc (MPa) 0.4 0.7 -0.8 -0.3 28-d fc (MPa) -10 0.6 0.5 -0.5 -0.6 1.5 -0.3 0 10 20 30 40 50 60 70 80

Compressive strength (MPa)

days 28 7 90 180 360 C3S C2S C3A C4AF C12A7

Hydration of pure phases according to Boque and Lerch

5.2 Color

• If % Fe₂O₃ is combined with Blaine specific surface (m2/kg), it is possible to explain 97% of the observed color variations.

5.3 Microscopy

a) Interpretation

Case Observations

1) Raw Mix

Raw mix fineness Siliceous rejects Belite ring around empty pores

Shaly rejects Belite ring around pores filled with celite Calcareous rejects Tight-grain free lime patches

Raw Mix Heterogenous Wide patches of belite that can exceed 500 µm Homogeneity Homogenous Alite and belite side by side, without belite patches Lime saturation Overdosage High free lime content with no or little belite Of raw mix Underdosage Little or no free lime, high belite content

Raw mix chemistry Alkalies _{Orthorhombic C A}

3 in needles if alkalies in crystal structure.

Cubic C₃A if alkalies in alkalie sulfate form.

2) Burning

Under burning Low Temperature High porosity (homogenous), much free lime dispensed, poorly shaped minute alite crystals.

Rapid Zone Passage Heterogeneous porosity, belite separated from lime by a thin alite streak.

Over burning High Temperature Low porosity, large alite and small pointe alite crystals, ferroaluminate needles, amoeboid belite

Slow zone passage at high To

Large fused alite crystals (cannibalism)

Atmosphere Reduced Ferroaluminate inclusions in alite, and lime on pore edges.

3) Cooling

Cooling rate Very high (quenching) Aluminates and ferroaluminates highly intermingles, fissured belite, and periclase in small crystals.

Slow Good separation between aluminates and ferroaluminates, belite borders around alite.

Very slow Belite shredded, spongy and mono striated, belite and periclase linkage even in clinker having less than 2% MgO.

b) Parameters Having an Impact on the Crystal Size

1 1 1 1 1

1 1 1 1 1

Diameter reduction (µm ) alite : belite :

+ 0,4% Equiv. -1% Exc SO3. / T ot. alk. Norm al hard burning + 4% C3A + 1% Free CaO Sol.Na ₂O 0 2 4 6 8 10

6. 10 Basic Facts on Clinker

Warning: Here, MPa are French standard (1.45 French MPa= 1 US/Can MPa)

1) Raw mix rejects The reduction of raw mix rejects reduces the burning temperature and the cement grinding energy:

100 µm R in raw mix: 20%
10% ➠ - 4 kWh/t on both raw mix & cement grinding.

This is particularly the case for siliceous rejects. This action is also rather favorable to strengths.

2) Heat profile A short profile helps grindability and strength development. Slow cooling adversely affects strengths and workability.

Clinkering level: 30 min.
60 min. ➠ - 3 to - 10 MPa in the laboratory. 3) Burning

atmosphere

Production uniformity requires an oxidizing atmosphere because a reducing atmosphere promotes volatilization ➠ "cyclic" operation, sulfate and alkali fluctuations, thus a non uniform clinker:

SO3 variation in clinker from 1 to 4 %➠variation in % alkali sulfates➠ possibility of large strength variations at 1 day.

4) Free lime content An increase in clinker free lime content reduces both initial and final setting times + 1 % free CaO ➠ - 50 min on average (- 10 à - 100 min depending on clinker).

Similarly, the addition of lime shortens both initial and final setting time. 5) ClinkerC₃S

content

An increase in clinker C₃S content (to the detriment of C₂S) improves strengths at 1, 2, 3 and 7 days: S C % 10 ₃ + ➠

+

2

to

+

5

MPa

At 28 days, the increase is less noticeable since there is also a contribution from S

C₂ . 6) ClinkerC₂S

content

At constant Blaine specific surface, grinding energy increases with C₂S content. Inversely it reduces with an increase in C₃S:

+ 10 % C2S➠+ 5 kWh/t for 350 m2/kg SSB 7) Clinker alkali

content

Alkalies always work against 28-day strengths no matter what form they are: + 0.1 % Na2O equiv.➠- 1 MPa

8) Clinker alkalies and sulfates

At optimum sulfate content for early ages, soluble alkalies, in particular in the form of sulfates, improve early strengths:

+ 0.1 % Na2O equiv.➠+ 0.5 à 1.5 MPa

Strengths improve with an increase in the C3A content.

9) Alkali saturation _{Alkali molar saturation by clinker SO3 facilitates control over workability:} Alkali saturation➠
water demand and  fluidity and early-age fc. 10) Excess Sulfate /

alkalies

If clinker SO₃ is increased beyond alkali molar saturation, a clinker fineness and grinding energy increase can be observed.

7. Raw Mix & Clinker Uniformity

7.1 TYTP Indicators •

∑

(

)

= − = N 1 i 2 T 3 i 3S C S C N 1

KFUI Target: Lafarge Corp < 10, Group < 14

•

(

)

∑

(

)

= − = N 1 i 2 average 3 i 3S C S C N 1 S 3 clkC . CUI Target < 16 • 100 SO x 1 SO KSUI 3 3 _× + = σ Target < 10 • 3 2 . 0 1 . 0 fCaO . fCaO x UI fCaO × + =

σ

Target < 1

- KFUI measures the ability to follow a raw mix _{C3S target. Clinker uniformity indicators measure the} variation from an average.

- Use first scheduled “grab” sample per day, with no calculation if there is less than 10 days production. Exception: Lafarge Corp. recommends KFUI calculation based on all samples.

- Indicators are calculated on a monthly and annual (12-month rolling average) basis for kiln main product only. The 12MRA KFUI is an average of the monthly results weighted by clinker tonnage, while clinker 12MRAs use 12-month variances and averages (_{C3S, SO3, f-CaO).}

- Combining indices for an aggregate plant index is done by weighting clinker tonnage.

7.2 Lafarge Corp Results

Kiln Pf >98% SUI <2.0 KFUI <10 KSUI <10 Idx F.L. <1.0 CUI <16

1998 1999 1998 1999 1998 1999 1998 1999 1998 1999 1998 1999 BTH 86.1 82.3 1.8 1.4 12.0 11.8 14.1 13.0 0.7 0.9 17.9 12.3 BFD 87.7 95.1 1.5 2.8 14.0 12.4 9.5 10.3 2.8 0.9 15.3 21.4 ESW 94.7 100.2 1.6 1.9 8.2 6.8 7.1 7.2 1.0 1.2 4.8 4.9 KAM 91.5 95.4 2.5 2.1 19.9 13.3 6.2 11.1 4.4 2.1 4.9 6.5 RMD 79.0 82.6 2.2 1.9 7.7 18.3 13.2 10.3 3.4 2.2 16.0 17.9 SEA 93.5 19.2 17.8 3.3 23.3 STC 90.6 91.9 1.0 1.4 7.6 12.6 15.0 17.2 1.4 1.3 15.0 7.1 WSK 91.1 89.0 1.7 1.5 6.9 5.7 12.2 12.3 1.5 1.6 5.8 6.7 All CDN 89.0 92.8 1.6 1.6 9.8 11.5 12.0 11.9 1.4 1.4 12.5 10.6 ALP 94.8 96.2 1.8 2.0 14.0 11.6 19.1 19.7 2.5 2.0 23.4 11.9 DAV 87.7 98.1 2.1 2.0 11.2 9.5 11.8 14.4 0.9 0.9 15.4 16.0 FDA 101.0 101.4 2.9 2.5 10.0 14.3 15.5 15.5 2.6 2.5 11.4 15.9 JPA 95.8 88.0 2.2 2.7 10.1 20.8 27.8 24.1 2.3 1.9 18.8 23.7 PDG 85.8 92.1 2.0 3.2 4.1 5.4 19.9 22.2 2.1 2.6 13.7 16.7 SCK 90.9 88.3 3.4 2.7 13.3 18.7 23.4 27.4 4.1 3.6 24.5 41.4 WHL 95.8 98.0 2.9 2.0 8.9 7.6 16.1 17.4 1.4 1.5 9.3 5.7 All U.S. 93.3 94.8 2.2 2.3 11.4 12.4 19.0 19.8 2.2 2.0 18.4 16.4 All N.A. 91.6 93.9 2.0 2.0 10.8 12.0 16.2 16.3 1.9 1.7 16.1 13.8

8. ASTM Standards

Comparison of Portland Cement Specifications

Updated - Nov. 21, 2000 NORMAL

(I/10)

MODERATE (II/20) HIGH EARLY (III/30) LOW HEAT

(IV/40)

SULFATE RESISTAT (V/50)

CHEMICAL REQUIREMENTS ASTM AASHTO CSA ASTM AASHTO CSA ASTM AASHTO CSA (a) ASTM AASHTO CSA ASTM AASHTO CSA

Si02, min., % 20.0 20.0

Al203, max., % 6.0 6.0

Fe203, max., % 6.0 6.0 6.5 6.5

Mg0, max., % 6.0 6.0 5.0 6.0 6.0 5.0 6.0 6.0 5.0 6.0 6.0 5.0 6.0 6.0 5.0

S03, max. % when:

C3A is 8% (7.5% for CSA) or less 3.0 3.0 3.0 3.0 3.0 3.0 3.5 3.5 3.5 2.3 2.3 2.5 2.3 2.3 2.5

C3A is more than 8% (7.5% for CSA) 3.5 3.5 3.5 (g) (g) (g) 4.5 4.5 4.5 (g) (g) (g) (g) (g) (g)

Loss On Ignition, max., % 3.0 3.0 3.0 (e) 3.0 3.0 3.0 3.0 3.0 3.0 (e) 3.0 3.0 3.0 3.0 3.0 3.0

Insoluble Residue, max., % 0.75 0.75 1.5 0.75 0.75 0.7 0.75 0.75 1.5 0.75 0.75 0.7 0.75 0.75 0.7

C3S, max., % 55 35 (h) 35 (h)

C2S, min., % 40 (h) 40 (h)

C3A, max., % (d) 8 8 7.5 15 15 7 (h) 7 (h) 5.5 5 (k) 5 (k) 3.5

(C4AF+2(C3A), or

(C4AF+C2F) as applicable, max., % 25 (k) 25 (k)

Na20+0.658 K20, max. % 0.60 (b) 0.60 (b) 0.60 (b) 0.60 (b) 0.60 (b) 0.60 (b) 0.60 (b) 0.60 (b) 0.60 (b) 0.60 (b)

Limestone, max., % 5 (a) 5 (a)

–

Comparison of Portland Cement Specifications

Updated - Nov. 21, 2000 NORMAL

(I/10) MODERATE (II/20) HIGH EARLY (III/30) LOW HEAT (IV/40) SULFATE RESISTAT (V/50)

PHYSICAL REQUIREMENTS ASTM AASHTO CSA ASTM AASHTO CSA ASTM AASHTO CSA (a) ASTM AASHTO CSA ASTM AASHTO CSA

Wagner Turbidimeter (n): Min. value, any one sample, m2/kg

160 150 160 150 160 150 160 150

Max. value, any one sample, m2/kg

230 230 230 230

Air Permeability Test (n): Min. value, any one sample, m2/kg

280 260 280 260 280 260 280 260

Max. value, any one sample, m2/kg

Average value max., m2/kg 400 400 400 400

Minimum Passing 45um Sieve, % 72 72 72

Soundness (autoclave expansion), max.,%

0.80 0.80 1.0 0.80 0.80 1.0 0.80 0.80 1.0 0.80 0.80 1.0 0.80 0.80 1.0

Time of Setting (o): Vicat Test

-Minimum not less than, min. 45 45 45 45 45 60 45 45 45 45 45 90 45 45 60

Maximum not more than, min. 375 375 360 375 375 360 375 375 250 375 375 360 375 375 360

Gillmore Test

-Int. set, not less than, min. 60 60 60 60 60 60 60 60 60 60

Fin. set, not more than, min. 600 600 600 600 600 600 600 600 600 600

Air Content of Mortar (i), max., volume %

12 12 12 12 12 12 12 12 12 12

Comressive Strength, psi (MPa):

1-day minimum 1740

(12.0)

1800 (12.4) 13.5 MPa

1-day maximum 36 MPa (v)

3-day minimum 1740(12.0 1800 (12.4) 14.5 MPa

1450(10.0) 1500(10.3) 14.5 MPa

3480(20.0) 3500 (24.1) 24.0 MPa 8.5 MPa 1160(8.0) 1200 (12.3) 14.5 MPa

3-day maximum 32.5 MPa 32.5 MPa 43.0 MPa (v) 32.5 MPa (v) 7-day minimum 2760(19.0 2800 (19.3) 20.0 MPa 2470(12.0) 2500 (17.2) 20.0 MPa 1020(7.0) 1000 (6.9) 2180(15.0) 2200 (15.1) 20.0 MPa 7-day maximum 40.0 MPa 40.0 MPa 40.0 MPa (v) 28-day minimum 26.5 MPa 26.5 MPa 38.0 MPa 2470(17.0) 2500 (17.2) 25.0 MPa 3050 (21.0) 3000 (20.7) 26.5 MPa 28-day maximum 51.0 MPa 51.0 MPa 60.0 MPa (v) 51.0 MPa (v) 28-day, C.V., max., % 8 8 8 8 91-day minimum 33.0 MPa Heat of Hydration: 7-day, max., kJ/kg (cal/g) 290 (70) (p) 290(70) (p) 300 (s) 250 (60) (q) 250 (60) 275 28-day, max., kJ/kg (cal/g) 290 (70) (q) 290 (70) Paste False Set (early stiffening),

min., %

50 (x) 50 (x) 50 (x) 50 (x) 50 (x) 50 (v) 50 (v) 50 (v) 50 (v) 50 (v)

Sulfate Expansion, (j):

14-day, max. % 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020

Foot notes onComparison of Portland Cement Specifications

(a) CSA A5 recognizes the existence of an optimum carbonate addition for some Portland cements. Therefore, a maximum of 5% addition of limestone is permitted for Type 10 and Type 30 cement.

(b) This optional limit may be specified when the cement is to be used in concrete with aggregates that may be deleteriously reactive. (d) For C3A calculation, ASTM, AASHTO and CSA use Al2O3 only without TiO2 and P2O5.

(e) A loss on ignition of 3.5% is allowed for Type 10 and Type 30 Portland cements provided that such cements when tested in accordance with the CSA Standard, but at a furnace temperature of 550oC, show a loss in mass of no more than 3.0%.

(f) The optional limit for heat of hydration shall not be requested when this optional limit is specified. (g) Not applicable.

(h) Does not apply when the heat of hydration limit is specified. (i) ASTM & AASHTO allow 16-22% air in Types IA, IIA, IIIA. (j) Required if SO3 exceeds the table limits.

(k) Does not apply when the sulfate resistance limit is specified.

(n) Either of the two alternative fineness methods may be used at the option of the testing laboratory. However, in the case of ASTM, the turbidimeter is the referee method; average value shall be determined on the last consecutive five samples from a source.

(o) The purchaser should specify the type of setting time test required. In case he does not so specify, the requirements of the Vicat test only shall govern; CSA only specifies Vicat test.

(p) The optional limit for the sum of the C3S and C3A shall not be requested when this optional limit is requested. These strength requirements apply when either heat of hydration or the sum of C3S and C3A requirements are requested.

(q) When heat of hydration limit is specified, it shall be instead of the limits of C3S, C2S and C3A.

(s) The requirement of either heat of hydration or sulfate resistance may be specified at the option of the purchaser. (t) Optional, it shall be instead of the limits of C3A and C4AF+2C3A.

(v) This value indicates requirement to be specified at the option of the purchaser. CTS - Products and Quality,

ASTM Optional Physical Requirements

Cement Type I Ia II IIa III IIIa IV V

Fineness Max for AASHTO ** Wagner Blaine 4000 2200 4000 2200 4000 2200 4000 2200

False set final penetration min (%) 50 50 50 50 50 50 50 50

Heat of hydration

7 days max (Ical/g) 28 days max (cal/g)

-70 -70 -60 70 -Compressive strength min (psi)

28 days 4000 3200 4000

3200* 3200 2560*

- - -

-Sulphate expansion 14 days max (%) - - - 0.045

* _{Apply when either the heat of hydration or C3S + C3A are specified.} ** American Association of State Highway and Transportation Officials. ASTM Standard Physical Requirements

Cement Type I Ia II IIa III IIIa IV V

Air content of motar Max % Min % 12 -22 16 12 -22 16 12 -22 16 12 -12 -Fineness min Turbidimeter (m2/kg) Air permeab (m2/kg) 160 280 160 280 160 280 160 280 -160 280 160 280 Compressive strength min (psi)

1 day 3 day 7 days 28 days -1800 2800 -1450 2250 -1500 1000* 2500 1700 -1200 800* 2000 1350 -1800 3500 -1450 2800 -1000 2500 -1200 2200 3000 Setting time

GilmoreInitial set min (min) Final set max (h)

VicatInitial set min (min) Final set max (h)

60 10 45 8 60 10 45 8 60 10 45 8 60 10 45 8 60 10 45 8 60 10 45 8 60 10 45 8 60 10 45 8 * _{When optional heat of hydration or chemical limit on C3S + C3A is specified.}

ASTM Optional Chemical Requirements

Cement Type I Ia II Iia III IIIa IV Iva V Va Remarks A

C₃ - - 8 - - Moderate sulphate resistance

S

C₃ - - 5 - - High sulphate resistance

S C A

C₃ + ₃ - 58 - - - Moderate heat of hydration

O

K

658

.

0

O

Na

₂

+

₂ 0.60 0.60 0.60 0.60 0.60 Low-alkali cement

Comparison of Blended Hydraulic Cement Specifications

ASTM C-1157-94a and C-595-94a, AASHTO M240-92, and CSA-A362-93

10/27/94 ASTM C-1157-94a ASTM C-595-94a AASHTO M240-92 CSA-A362-93

CEMENT TYPE GU HE MS HS MH LH L(SM) IS S L(PM) IP P I(SM) IS S L(PM) IP P 10SM 10S 10FM 10F 10SF

Slag content, % <25 25-70 >70 <25 25-70 >70 <25 25-70

Pozzolan content, % <15 15-40 >40? <15 15-40 >40? <15 15-40

Silica fume content, % <10

CHEMICAL REQUIREMENTS

SiO2, min., % c c c c c c c c c c c c

Al2O3, max., % c c c c c c c c c c c c

CaO, max., % c c c c c c c c c c c c

MgO, max., % 6.0 6.0 6.0 5.0 5.0 5.0 5.0 5.0 5.0

SO3, max., % a a a a a a 3.0 (d) 3.0 (d) 4.0 (d) 4.0 (d) 4.0 (d) 4.0 (d) 3.0 (d) 3.0 (d) 4.0 (d) 4.0 (d) 4.0 (d) 4.0 (d) 3.0 (e) 3.0 (e) 3.0 (e) 3.0 (e) 3.0 (e)

Sulfide S, max, % 2.0 2.0 2.0 2.0 2.0 2.0 1.0 2.0

Loss On Ignition, max., % 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 4.5 6.0 3.5

Insoluble Residue, max., % 1.0 1.0 4.0 5.0 5.0 5.0 1.0 1.0 4.0 5.0 5.0 5.0 1.0 1.0

Comparison of Blended Hydraulic Cement Specifications (continued) ASTM C-1157-94a and C-595-94a, AASHTO M240-92, and CSA-A362-93

10/27/94 ASTM C-1157-94a ASTM C-595-94a AASHTO M240-92 CSA-A362-93

CEMENT TYPE GU HE MS HS MH LH L(SM) IS S L(PM) IP P I(SM) IS S L(PM) IP P 10SM 10S 10FM 10F 10SF

PHYSICAL REQUIREMENTS

Air permeability test: b b b b b b b b b b b b b b b b b b 24.0 24.0 24.0 24.0 24.0

Max. retained on 45µm Sieve, % b b b b b b b b b b b b b b b b b b

Autoclave contraction, max., % 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.50 0.50 0.50 0.50 0.50 0.50 0.8 0.8 0.8 0.8 0.8

Autoclave contraction, max., % 0.80 0.80 0.80 0.80 0.80 0.80 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 Time of Setting:

Vicat test

-Minimum not less than, min. 45 45 45 45 45 45 45 45 45 45 45 45 45 45 45 45 45 45 45 45 45 45 45

Maximum not more than, h. 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 6 8 6 8 6

Air content of mortar, max., volume %

b b b b b b 12 12 12 12 12 12 12 12 12 12 12 12

Compressive Strength, min., MPa (psia): 1-day 12 (1740) 3-day 12 (1740) 24 (3480) 10 (1450) 8 (1160) 7 (1015) 12.4 (1800) 12.4 (1800) 12.4 (1800) 12.4 (1800) 12.4 (1800) 12.4 (1800) 12.4 (1800) 12.4 (1800) 12.0 9.0 12.0 9.0 12.0 7-day 20 (2900) 17 (2465) 15 (2175) 12 (1740) 7 (1015) 19.3 (2800) 19.3 (2800) 4.1 (600) 19.3 (2800) 19.3 (2800) 10.3 (1500) 19.3 (2800) 19.3 (2800) 4.1 (600) 19.3 (2800) 19.3 (2800) 10.3 (1500) 18.0 15.0 18.0 15.0 13.0 28-day 28 (4060) (m) 28 (4060) (m) 20 (2900) 22 (3190) (m) 17 (2465) 24.1 (3500) 24.1 (3500) 10.3 (1500) 24.1 (3500) 24.1 (3500) 20.7 (3000) 24.1 (3500) 24.1 (3500) 10.3 (1500) 24.1 (3500) 24.1 (3500) 20.7 (3000) 26.0 26.0 (j) 26.0 26.0 (j) 26.0 Heat of hydration:

7-day, max., kJ/kg (cal/g) 290

(70) 250 (60) 293 (70) (f) 293 (70) (f) 293 (70) (f) 293 (70) (f) 251 (60) (f) 293 (70) (f) 293 (70) (f) 293 (70) (f) 293 (70) (f) 251 (60) (f)

287-day, max., kJ/kg (cal/g) 290

(70) 335 (80) (f) 335 (80) (f) 335 (80) (f) 335 (80) (f) 293 (70) (f) 335 (80) (f) 335 (80) (f) 335 (80) (f) 335 (80) (f) 293 (70) (f) 300 (g) 300 (g) Paste false set (early stiffening),

min, %

Water requirement, max, wt.% of cement

64 64

Comparison of Blended Hydraulic Cement Specifications (continued) ASTM C-1157-94a and C-595-94a, AASHTO M240-92, and CSA-A362-93

10/27/94 ASTM C-1157-94a ASTM C-595-94a AASHTO M240-92 CSA-A362-93

CEMENT TYPE GU HE MS HS MH LH L(SM) IS S L(PM) IP P I(SM) IS S L(PM) IP P 10SM 10S 10FM 10F 10SF

PHYSICAL REQUIREMENTS

Mortar expansion(I):

14-day, max. % 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 0.020 8-week, max. % 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 0.060 Sulfate resistance at 6 months:

Moderate resistance, max., % 0.10 0.10(k

) 0.10(k ) 0.10(k ) 0.10(k ) 0.10(k )

High resistance, max., % 0.05 0.05(k

) 0.05(k ) 0.05(k ) 0.05(k ) 0.05(k ) Sulfate resistance at 1 year:

Moderate resistance, max., %

High resistance, max., % 0.10

(a) Any amount of SO3up to the maximum amount that causes an expansion of 0.020% at 14 days of water immersion when tested by C 1038.

(b) No limit, but test results shall be reported on all certificates requested from the manufacturer.

(c) If the purchaser has requested the manufacturer to state in writing the composition of the blended cement purchased, the composition of the cement furnished shall conform to that shown in the statement within the tolerances of +/-3% for SiO2and CaO, and +/-2% for Al2O3.

(d) When optimum SO3tested by C563 exceeds a value 0.5% less than the specified limit, and additional amount of SO3is permissible provided that, when the cement with the additional calcium sulfate is tested by

C265, the calcium sulfate in the hydrated mortar at 24+/-0.25 h, expressed as SO3, does not exceed 0.50g/L. When the manufacturer supplies cement under this provision, he will, upon request, supply supporting data

to the purchaser.

(e) This limit may be exceeded provided that the cement exhibits expansion not in excess of 0.020% at 14 days when tested in accordance with Clause 7.5.5 of CSA-A5. (f) Applicable only when moderate (MH) or low (LH) heat of hydration is specified, in which case the strength requirements shall be 80% of the values shown in the table.

(g) Applicable at the purchaser’s option, when moderate heat of hydration is required, the heat of hydration shall be determined in accordance with ASTM C186. Errors in C186 test can occur when testing blended hydraulic cements, due to the effect of oxidation of sulfides in slags or loss on ignition or due to incomplete solubility of fly ash or silica fume in nitric acid. The magnitude of these errors is unknown at this time. (i) To be applied only at the purchaser’s request and should not be requested unless the cement will be used with alkali-reactive aggregate.

(j) When moderate heat of hydration is required, the minimum 28-day strength requirements shall be 80% of the value shown and the 91-day strength shall be a minimum of 26.0 MPa.

(k) Applicable at purchaser’s option. The sulfate resistance shall be determined in accordance with ASTM C1012. If expansion is greater than 0.05% at 6 months but less than 0.10% at one year, then the cement will be considered to be high sulfate resistance.

(l) Applicable only when the cement is specified to be nonstaining to limestone. (m) Optional.