Portland, Blended, and Other Hydraulic Cements EB 101 Design and Control of Concrete Mixtures-7th Canadian Edition-2002 (updated 2004) Fig. 2-1. Portland cement is a fine powder that when mixed with water becomes the glue that holds aggregates together in concrete. (58420)

Oldest Concrete Found To Date dates around 7000 BC — a lime concrete floor found during the construction of a road at Yiftah El in Galilee, Israel.

Portland Cements General— are hydraulic cements composed primarily of hydraulic calcium silicates that set and harden by reacting chemically with water.

Beginning of the Industry Portland cement was first patented by Joseph Aspdin, an English mason in 1824. Named it after the natural limestone quarried on the Isle of Portland in the English Channel. Fig. 2-2. Isle of Portland quarry stone (after which portland cement was named) next to a cylinder of modern concrete. (68976)

Portland cement first produced North America 1871— Coplay, Pennsylvania Canada 1889 — Hull, Quebec Lime and hydraulic cement first produced in Canada as early as 1830 to 1840 in Hull. Canadian natural cement producers converted existing facilities to produce superior portland cement C.B.Wrright & Sons , Hull, Quebec frst portland cement producer in Canada and almost at the same time by Napanee Cement Works, Napanee, Ontario. Two new plants for the production of portland cement followed shortly, one in Shallow Lake, near Owen Sound, Ontario, and the other at Longue Pointe, east of Montreal.

Fig. 2-5. Aerial view of a cement plant. (70000)

Primary Components of Raw Materials Necessary for Portland Cement Manufacture Calcium Silica Alumina Iron Materials used in the manufacture of portland cement must contain appropriate proportions of calcium, silica, alumina, and iron components

Calcium Iron Silica Alumina Sulphate Alkali waste Aragonite Calcite Cement-kiln dust Cement rock Chalk Clay Fuller’s earth Limestone Marble Marl Seashells Shale Slag Blast-furnace flue dust Iron ore Mill scale Ore washings Pyrite cinders Calcium silicate Fly ash Loess Quartzite Rice-hull ash Sand Sandstone Traprock Aluminum-ore refuse Bauxite Copper slag Granodiorite Staurolite Anhydrite Calcium sulphate Gypsum Table 2-1. Sources of Raw Materials Used in Manufacture of Portland Cement Sulphate, often in the form of gypsum, is added during the grinding of the clinker to regulate the setting time of the cement and to improve shrinkage and strength development properties.

Quarry Fig. 2-6. Limestone, a primary raw material providing calcium in making cement, is quarried near the cement plant. (59894) Fig. 2-7. Quarry rock is trucked to the primary crusher. (59893)

Manufacture of Portland Cement Traditional Processes Fig. 2-3. Steps in the traditional manufacture of portland cement 1. Stone is first reduced to 125 mm size, then to 20 mm, and stored.

Raw materials are ground to powder and blended. or 2. Raw materials are ground, mixed with water to form slurry, and blended. Fig. 2-3. Steps in the traditional manufacture of portland cement

3. Burning changes raw mix chemically into cement clinker. Fig. 2-3. Steps in the traditional manufacture of portland cement

4. Clinker with gypsum is ground into portland cement and shipped. Fig. 2-3. Steps in the traditional manufacture of portland cement

Quarry

Raw material storage

Measurement of chemical composition

Manufacture of Portland Cement Modern Dry - Process Fig. 2-4. Steps in the modern dry-process manufacture of portland cement. 1. Stone is first reduced to 125 mm size, then to 20 mm, and stored.

Raw materials are ground, to powder and blended. Fig. 2-4. Steps in the modern dry-process manufacture of portland cement.

3. Burning changes raw mix chemically into clinker 3. Burning changes raw mix chemically into clinker. Note four stage preheater, flash furnaces, and shorter kiln. Fig. 2-4. Steps in the modern dry-process manufacture of portland cement.

4. Clinker with gypsum is ground into portland cement and shipped Fig. 2-4. Steps in the modern dry-process manufacture of portland cement.

Fig. 2-8. Rotary kiln (furnace) for manufacturing portland cement clinker. Inset view inside the kiln. (58927, 25139)

Clinker Gypsum Fig. 2-9. Portland cement clinker is formed by burning calcium and siliceous raw materials in a kiln. This particular clinker is about 20 mm in diameter. (60504) Fig. 2-11. Gypsum, a source of sulphate, is interground with portland clinker to form portland cement. It helps control setting, drying shrinkage properties, and strength development. (60505)

Process of Clinker Production Fig. 2-10. Process of clinker production from raw feed to the final product (Hills 2000). (1)

Fig. 2-10. Process of clinker production from raw feed to the final product (Hills 2000). (2)

Fig. 2-10. Process of clinker production from raw feed to the final product (Hills 2000). (3)

Portland Cement CSA A5 By definition — is the product obtained by pulverizing clinker consisting essentially of hydraulic calcium silicates to which various forms of calcium sulphate, limestone, water, and processing additions may be added at the option of the manufacturer.

Types of Portland Cement CSA A5 (old) Type 10 Normal Type 20 Moderate* Type 30 High-early-strength Type 40 Low-heat of hydration Type 50 Sulphate-resistant *Moderate with respect to the heat of hydration or sulphate resistance.

Types of Portland Cement ASTM C 150 I Normal IA Normal, air-entraining II Moderate sulfate resistance IIA Moderate sulfate resistance, air-entraining III High early strength IIIA High early strength, air-entraining IV Low heat of hydration V High sulfate resistance

CSA-A3000 Cementitious Materials Compendium A5 Portland Cement A8 Masonry Cement A362 Blended Hydraulic Cement A363 Cementitious Hydraulic Slag A23.5 Supplementary Cementing Materials In Canada – the national standard for cementitious materials is CSA-A-3 thousand. The 1998 version of this compendium provided for fours classes of hydraulic cements, these being: A5 - Portland Cement A8 - Masonry Cement A3-62 - Blended Hydraulic Cement and A3-63 - Cementitious Hydraulic Slag A3000 also included A23-point-5 which covered supplementary cementing materials such as fly ash, slag, silica fume and natural pozzolans

CSA-A3000-03 Cementitious Materials Compendium A3001—Cementitious Materials for Use in Concrete A3002—Masonry and Mortar Cement A3003—Chemical Test Methods A3004—Physical Test Methods In 2004 – CSA A3000 was reorganized into four sections A3001 covers cementing materials for use in concrete including portland and blended cements, pozzolans and ground granulated blast-furnace slag A3002 covers cements used in masonry and mortar, And A 3003 and 3004 cover test methods for all cements

CSA-A3001 Cementitious Materials for Use in Concrete Portland Cements Blended Hydraulic Cements Supplementary Cementing Materials Blended Supplementary Cementing Materials CSA A3001 covers all cementing materials used in concrete including:- Portland Cements and Blended Hydraulic Cements, which will be briefly discussed here. A3001 also covers Supplementary Cementing Materials and Blended Supplementary Cementing Materials, which will not be discussed.

CSA-A3001 Cementitious Materials for Use in Concrete Portland Cements Portland Cement Type Name GU General use cement MS Moderate sulfate-resistant cement MH Moderate heat of hydration cement HE High early-strength cement LH Low heat of hydration cement HS High sulfate-resistant cement CSA A3001 provides for six types of portland cement; these are Type GU - General use cement Type MS - Moderate sulfate-resistant cement Type MH - Moderate heat of hydration cement Type HE - High early-strength cement Type LH - Low heat of hydration cement And Type HS - High sulfate-resistant cement

CSA-A3001 Cementitious Materials for Use in Concrete Portland Cements Portland Cement Type Name GU General use cement MS Moderate sulfate-resistant cement MH Moderate heat of hydration cement HE High early-strength cement LH Low heat of hydration cement HS High sulfate-resistant cement CSA A5-98 Type 10 Type 20 Type 30 Type 40 Type 50 ASTM C 150 Type I Type II Type III Type IV Type V The physical and chemical requirements for these cements are essentially the same as those for Types 10 through 50 in the previous specification, CSA A5, And similar to those for Types 1 through 5 in ASTM C 1-50.

Fig. 2-12. Typical uses for Type 10 Normal portland or general use cements include (left to right) highway pavements, floors, bridges, and buildings. (68815, 68813, 63303, 68809)

Cement Type Required for Concrete Exposed to Sulphates Class & Degree of Exposure Water-soluble sulphate (SO4) in soil, % Sulphate (SO4) in groundwater, mg/L Cement Type S-1 Very Severe Over 2.0 Over 10,000 50 S-2 Severe 0.20 to 2.0 1500 to 10,000 S-3 Moderate 0.10 to 0.20 150 to 1500 20E, 40, or 50E This Table adapted from Table 2.2 Requirements for Concrete Subjected to Sulphate Attack-EB101 Type 50E cement should not be used in reinforced concrete exposed to both chlorides and sulphates. Refer to CSA A23.1 Clause 15.4

Cement Type Required for Concrete Exposed to Sulphates Class & Degree of Exposure Water-soluble sulphate SO4 in soil, ( %) Sulphate (SO4) in groundwater, mg/L Min. specified 56-day comp. str., MPa Max. w/cm ratio CementingMaterial to be used S-1 Very Severe Over 2.0 Over 10,000 35 0.40 50 S-2 Severe 0.20 to 2.00 1500 to 10,000 32 0.45 S-3 Moderate 0.10 to 0.20 150 to 1500 30 0.50 20E, 40, or 50E Table 2-2. Requirements for Concrete Subjected to Sulphate Attack (Same as Table 9-2) Air content category for all exposures is 2. Exception is for steel-trowled interior slabs on grade in a non freeze thaw environment, air entrainment is not required. Type 50E cement shall not be used in reinforced concrete exposed to both chlorides and sulphates.

Performance of Concretes Made with Different Cements in Sulphate Soil Fig. 2-13. (top) Performance of concretes made with different cements in sulphate soil. Type II (20) and Type V (50) cements have lower C3A contents that improve sulphate resistance.

Performance of Concretes Made with Different W/C-Ratios in Sulphate Soil Improved sulphate resistance results from low water to cementing materials ratios as demonstrated over time for concrete beams exposed to sulphate soils in a wetting and drying environment. Shown are average values for concretes containing a wide range of cementing materials, including cement Types I, II, V (10, 20, 50), blended cements, pozzolans, and slags.

Type 20 & Type 50 Sulphate Resistant Cements Fig. 2-14. Moderate sulphate resistant cements and high sulphate resistant cements improve the sulphate resistance of concrete elements, such as slabs on ground, pipe, and concrete posts exposed to high-sulphate soils. (68985, 52114, 68986)

Outdoor Sulphate Test Type 50 Cement Type 50 Cement W/C-ratio = 0.65 Fig. 2-15. Specimens used in the outdoor sulphate test plot in Sacramento, California, are 150 x 150 x 760-mm beams. A comparison of ratings is illustrated: (left) a rating of 5 for 12-year old concretes made with Type V (50) cement and a water-to-cement ratio of 0.65; and (right) a rating of 2 for 16-year old concretes made with Type V (50) cement and a water-to-cement ratio of 0.39 (Stark 2002). (68840, 68841)

Type 20 & Type 40 Moderate and Low Heat Cements Fig. 2-16. Moderate heat and low heat cements minimize heat generation in massive elements or structures such as (left) very thick bridge supports, and (right) dams. Hoover dam, shown here, used a Type 40 cement to control temperature rise. (65258, 68983)

Type 30 High Early Strength Cement Fig. 2-17. High early strength cements are used where early concrete strength is needed, such as in (left to right) cold weather concreting, fast track paving to minimize traffic congestion, and rapid form removal for precast concrete. (65728, 59950, 68668)

White Portland Cement Fig. 2-18. White portland cement (usually Type 10 or 30) is used in white or light-coloured architectural concrete, ranging from (left to right) terrazzo for floors shown here with white cement and green granite aggregate (68923), to decorative and structural precast and cast-in-place elements (68981), to building exteriors. The far right photograph shows a white precast concrete building housing the ASTM Headquarters in West Conshohocken, Pennsylvania. Photo courtesy of ASTM.

Blended Hydraulic Cement CSA A362 (old) General — is a product consisting of a mixture of portland cement or clinker and gypsum, blended or interground with one or more of granulated blast-furnace slag, fly ash, or silica fume.

Blended Cements Clinker Gypsum Portland cement Fly ash Slag Silica Fume Calcined Clay (not covered in CSA A362 only ASTM) Fig. 2-19. Blended cements CSA A362(ASTM C 595, and ASTM C 1157) use a combination of portland cement or clinker and gypsum blended or interground with slag, fly ash.or silica fume.ASTM also cover other pozzolans. ASTM C 1157 allows the use and optimization of all these materials, simultaneously if necessary, to make a cement with optimal properties. Shown is blended cement (centre) surrounded by (right and clockwise) clinker, gypsum, portland cement, fly ash, slag, silica fume, and calcined clay. (68988) Calcined clay is not covered in CSA A362 only ASTM Standards.

Types of Blended Hydraulic Cements CSA A362 Portland blast-furnace slag cement (S) Portland fly ash cement (F) Portland silica fume cement (SF) Ternary blend cement

Blended Cements Nomenclature & Naming Practice TE-A/B Where— T = the equiv. performance to Type 10, 20, 30, 40 or 50 portland cement E = an indication the cement has equivalent performance for the physical properties in CSA A362 A = the predominant SCM B = secondary SCM, only spec. in ternary blend

Blended Cements Examples of CSA A362 10E-S — a portland cement blast- furnace slag cement having equiv. performance to that of a Type 10 40E-F — a portland fly ash cement with equiv. performance to Type 40 50E-S/SF — a ternary blend cement with equiv. performance to a Type 50 portland cement with slag the predominant SCM and silica fume the secondary SCM

Portland Blast-Furnace Slag Cement Types 10E-S, 20E-S, 30E-S, 40E-S or 50E-S Slag content greater than 0% and less than 70% of total mass.

Portland Fly Ash Cement Types 10E-F, 20E-F, 30E-F, 40E-F or 50E-F Fly ash content greater than 0% and less than 40% of total mass

Portland Silica Fume Cement Type 10E-SF, 20E-SF, 30E-SF, 40E-SF or 50E-SF Silica fume content not to exceed 10% of total mass

Ternary Blended Cement Type 10E-A/B, 20E-A/B, 30E-A/B, 40E-A/B or 50E-A/B — a product of portland cement and two of: blast-furnace slag, fly ash or silica fume. Total SCM content > 0% and ≤ 70% of total mass Slag content < 70% of total mass Fly Ash content < 40% of total mass Silica Fume content <10% of total mass

CSA-A3001 Cementitious Materials for Use in Concrete Blended Hydraulic Cements Portland Cement Type Blended hydraulic cement type Name GU GUb General use cement MS MSb Moderate sulfate-resistant cement MH MHb Moderate heat of hydration cement HE HEb High early-strength cement LH LHb Low heat of hydration cement HS HSb High sulfate-resistant cement A3001 also provides for six types of blended cement. The suffix “b” is added to the designation to indicate that the product is a blended cement. Blended cements have slightly different physical and chemical requirements to portland cements – although the strength requirements are the same.

CSA-A3001 Cementitious Materials for Use in Concrete Blended Hydraulic Cements Nomenclature BHb-Axx\Byy\Czz BHb = blended hydraulic cement type The naming practice for blended cement is as follows:- First the blended hydraulic cement type is listed with the suffix “b” Then the amount and type of the predominant supplementary cementing material in the blend is listed If a second or third SCM is incorporated in the blend these are also listed A = percentage of predominant SCM xx = predominant SCM B = percentage of secondary SCM yy = secondary SCM C = percentage of tertiary SCM zz = tertiary SCM

CSA-A3001 Cementitious Materials for Use in Concrete Blended Hydraulic Cements Nomenclature BHb-Axx\Byy\Czz F = Type F Fly Ash The designations for the various SCM’s are:- F, CI or CH for the various types of fly ash S for slag SF for silica fume and N for natural pozzolan CI = Type CI Fly Ash CH = Type CH Fly Ash S = Ground Granulated Blastfurnace Slag SF = Silica Fume N = Natural Pozzolan

CSA-A3001 Cementitious Materials for Use in Concrete Blended Hydraulic Cements Nomenclature BHb-Axx\Byy\Czz HSb-25CI/10S A high sulfate-resistant blended cement with 25% Type CI fly ash and 10% slag So for example:- A cement designated as H – S – b – hyphen – 25 – C – I – slash – 10 – S indicates:- a high sulfate-resistant blended cement with 25% type CI fly ash and 10% slag Similarly, Type M – H – b – hyphen – 30 – F – slash – 10 – S – slash – 5 – CH indicates:- a moderate heat of hydration blended cement with 30% Type F fly ash, 10% slag and 5% Type CH fly ash The proportions of SCM are expressed as a percentage of the total cementing material. So in the last example – the total SCM content is 45% and the remaining 55% will be portland cement – or a combination of portland cement clinker and gypsum. MHb-30F/10S/5CH A moderate heat of hydration blended cement with 30% Type F fly ash, 10% slag and 5% Type CH fly ash Proportions of SCM expressed as a percentage of total cementing material.

CSA-A3001 Cementitious Materials for Use in Concrete Blended Hydraulic Cements Maximum amount of SCM’s Slag Fly Ash Natural pozzolan Silica Fume Total SCM 70% 50% 40% 15% 70% (when one SCM used) 70% (when slag and silica fume used) 60% (when 2 or more other SCM’s used) There are limits to the amount of SCM’s that may be incorporated in a blended cement these being:- 70% for slag, 50% for fly ash, 40% for natural pozzolan and 15% for silica fume The total SCM content must be less than 70% for a blended cement containing either one SCM, or a combination of silica fume and slag, and less than 60% for a blended cement with two or more other SCM’s

Portland Cements CSA A5 vs. ASTM C 150 ASTM C 150 Types I, II, III, IV and V are essentially the same as CSA A5 Types 10 through Type 50 respectively. with the exception — CSA A5 allow up to 5% limestone addition in Types 10 and Type 30 cement. This is currently not allowed in ASTM Standard C150.

Blended Hydraulic Cements ASTM C 595 Type IS Portland blast-furnace slag cement Type IP Portland-pozzolan cement Type P Portland-pozzolan cement Type I(PM) Pozzolan-modified portland cement Type S Slag cement Type I(SM) Slag-modified portland cement

Hydraulic Cements ASTM C 1157 First performance specification for hydraulic cements Cements meet physical performance test requirements rather than prescriptive restrictions on ingredients or cement chemistry as in other cement specifications. Provides for six types

Hydraulic Cement ASTM C 1157 Type GU General use Type HE High early strength Type MS Moderate sulphate resistance Type HS High sulphate resistance Type MH Moderate heat of hydration Type LH Low heat of hydration

Blended Hydraulic Cements specification Cement Applications General purpose Moderate heat of hydration High early strength Low heat of sulphate resistance High sulphate Resistance to alkali-silica reactivity (ASR) CSA A5 10 20 30 40 50 — ASTM C 150 I II III IV V Low alkali option CSA A362 Blended Hydraulic Cements 10E-S 10E-F 10E-SF Ternary 10E-A/B 20E-S 20E-F 20E-SF 20E-A/B 30E-S 30E-F 30E-SF 30E-A/B 40E-S 40E-F 40E-SF 40E-A/B 50E-S 50E-F 50E-SF 50E-A/B ASTM C 1157 hydraulic cements GU MH HE LH MS HS Option R Table 2-3. Applications for Commonly Used Cements Check the local availability of specific cements as all cements are not available everywhere. The option for low reactivity with ASR susceptible aggregates can be applied to any cement type in the columns to the left. For ASTM C 1157 cements, the nomenclature of hydraulic cement, portland cement, air-entraining portland cement, modified portland cement, or blended hydraulic cement is used with the type designation.

Special cements Type Application White portland cements, ASTM C 150 CSA A5 I, II, III, V 10 White or colored concrete, masonry, mortar, grout, plaster, and stucco White masonry cements, ASTM C 91 CSA A8 M, S, N N,S White mortar between masonry units Masonry cements, ASTM C 91 Mortar between masonry units, plaster, and stucco Mortar cements, ASTM C 1329 Mortar between masonry units Plastic cements ASTM C 1328 M, S Plaster and stucco Expansive cements ASTM C 845 E-1(K), E-(M), E-1(S) Shrinkage compensating concrete Oil-well cements, API-10 A,B,C,D,E,F,G,H Grouting wells Water-repellent cements Tile grout, paint, and stucco finish coats Regulated-set cements Early strength and repair Table 2-4. Applications for Special Cements Portland cement Types I, II, and III and blended cement Types IS, IP, and I(PM) are also used in making mortar. Portland cement Types I, II, and III and blended cement Types IP, I(SM) and I(PM) are also used in making plaster.

Special cements Type Application Cements with functional additions, ASTM C 595 ASTM C 1157 General concrete construction needing special characteristics such as; water-reducing, retarding, air entraining, set control, and accelerating properties Finely ground (ultrafine) cement Geotechnical grouting Calcium aluminate cement Repair, chemical resistance and high temperature exposures Magnesium phosphate cement Repair and chemical resistance Geopolymer cement General construction, repair, waste stabilization Ettringite cements Waste stabilization Sulfur cements Rapid hardening hydraulic cement VH, MR, GC General paving where very rapid (about 4 hours) strength development is required Table 2-4. Applications for Special Cements

Hydraulic Slag Cements Defined in CSA as: Cementitious Hydraulic Slag CSA A363 —the product obtained by pulverizing a granulated blast-furnace slag that possesses hydraulic properties and to which various forms of calcium sulphate and processing additions may be added at the option of the manufacturer. : Hydraulic slag cements are like other cements that set and harden by a chemical interaction with water.

Masonry Cements CSA A8 (old) Type N — for Type N mortar or with portland cement for Type S mortar as per CSA A179* Type S — for Type S mortar as per CSA A179* *CSA A179 — Mortar and Grout for Unit Masonry Fig. 2-20. Masonry cement and mortar cement are used to make mortar to bond masonry units together. (68807)

CSA-A3002 Masonry and Mortar Cement Types of Masonry and Mortar Cement Cement Type Name N Type N masonry cement S Type S masonry cement MCN Type N mortar cement MCS Type S mortar cement CSA A 3002 covers four types of masonry and mortar cement. Cement Types N and S are masonry cements and Cement Types MCN and MCS are mortar cements

CSA-A3002 Masonry and Mortar Cement Types or Masonry and Mortar Cement Cement Type Name N Type N masonry cement S Type S masonry cement MCN Type N mortar cement MCS Type S mortar cement CSA A8-98 Type N Type S ASTM C91 Type N Type S Types N and S masonry cements are essentially the same as those provided for in the previous specification – CSA A8 – and are similar to Types N and S masonry cement covered in ASTM C91 Standard Specification for masonry cement Previous Canadian specifications did not cover mortar cements. Type MCN and Type MCS are similar to Types N and S mortar cement covered by ASTM C13-29 Standard specification for mortar cement As with ASTM – the principal difference between masonry and mortar cements is that the mortar cements have a lower maximum limit on air content and a flexural bond strength requirement. CSA does not provide for equivalent products to the Type M mortar and masonry cements covered by ASTM. ASTM C1329 Type N Type S

Stucco using Masonry or Plastic Cements Fig. 2-21. Masonry cement and plastic cement are used to make plaster or stucco for commercial, institutional, and residential buildings. Shown are a church and home with stucco exteriors. Inset shows a typical stucco texture. (69389, 67878, 68805)

Finely-Ground Cements Grout penetration in soil Fig. 2-22. (left) A slurry of finely ground cement and water can be injected into the ground, as shown here, to stabilize in-place materials, to provide strength for foundations, or to chemically retain contaminants in soil. (68810) Illustration (right) of grout penetration in soil.

Expansive Cement Concrete Fig. 2-23. Length-change history of shrinkage compensating concrete containing Type E-1(S) cement and Type I (Type 10) portland cement concrete (Pfeifer and Perenchio 1973).

Drinking Water Applications Fig. 2-24. Concrete has demonstrated decades of safe use in drinking water applications such as concrete tanks. (69082)

Chemical Compounds of Portland Cement Fig. 2-25. (left) Polished thin-section examination of portland clinker shows alite (C3S) as light, angular crystals. The darker, rounded crystals are belite (C2S). Magnification 400X. (right) Scanning electron microscope (SEM) micrograph of alite (C3S) crystals in portland clinker. Magnification 3000X. (54049, 54068)

Hydration Products Fig. 2-26. Electron micrographs of (left) dicalcium silicate hydrate, (middle) tricalcium silicate hydrate, and (right) hydrated normal portland cement. Note the fibrous nature of the calcium silicate hydrates. Broken fragments of angular calcium hydroxide crystallites are also present (right). The aggregation of fibres and the adhesion of the hydration particles is responsible for the strength development of portland cement paste. Reference (left and middle) Brunauer 1962 and (right) Copeland and Schulz 1962. (69110, 69112, 69099)

Portland Cement Compound Hydration Reactions (Oxide Notation) 2 (3CaO•SiO2) Tricalcium silicate + 11 H2O Water = 3CaO•2SiO2•8H2O Calcium silicate hydrate (C-S-H) + 3 (CaO•H2O) Calcium hydroxide 2 (2CaO•SiO2) Dicalcium silicate + 9 H2O = 3CaO•2SiO2•8H2O + CaO•H2O 3CaO•Al2O3 Tricalcium aluminate + 3 (CaO•SO3•2H2O) Gypsum + 26 H2O = 6CaO•Al2O3•3SO3•32H2O Ettringite 2 (3CaO•Al2O3) + 6CaO•Al2O3•3SO3•32H2O + 4 H2O = 3 (4CaO•Al2O3•SO3•12H2O) Calcium monosulphoaluminate + 12 H2O = 4CaO•Al2O3•13H2O Tetracalcium aluminate hydrate 4CaO• Al2O3•Fe2O3 Tetracalcium aluminoferrite + 10 H2O + 2 (CaO•H2O) = 6CaO•Al2O3•Fe2O3•12H2O Calcium aluminoferrite hydrat Table 2-5. Portland Cement Compound Hydration Reactions (Oxide Notation) Note: This table illustrates only primary transformations and not several minor transformations. The composition of calcium silicate hydrate (C-S-H) is not stoichiometric (Tennis and Jennings 2000).

SEMs of Hardened Cement Paste Fig. 2-27. Scanning-electron micrographs of hardened cement paste at (left) 500X, and (right) 1000X. (A7112, A7111)

Fig. 2-28. Relative volumes of the major compounds in the microstructure of hydrating portland cement pastes (left) as a function of time (adapted from Locher, Richartz, and Sprung 1976) and (right) as a function of the degree of hydration as estimated by a computer model for a water to cement ratio of 0.50 (adapted from Tennis and Jennings 2000). Values are given for an average Type 10 (Type I) cement composition (Gebhardt 1995): C3S=55%, C2S=18%, C3A=10% and C4AF=8%. “AFt and AFm” includes ettringite (AFt) and calcium monosulphoaluminate (AFm) and other hydrated calcium aluminate compounds. See Table 2-5 for compound transformations.

Fig. 2-28. Relative volumes of the major compounds in the microstructure of hydrating portland cement pastes (left) as a function of time (adapted from Locher, Richartz, and Sprung 1976) and (right) as a function of the degree of hydration as estimated by a computer model for a water to cement ratio of 0.50 (adapted from Tennis and Jennings 2000). Values are given for an average Type 10 (Type I) cement composition (Gebhardt 1995): C3S=55%, C2S=18%, C3A=10% and C4AF=8%. “AFt and AFm” includes ettringite (AFt) and calcium monosulphoaluminate (AFm) and other hydrated calcium aluminate compounds. See Table 2-5 for compound transformations.

Chemical composition, % Type of portland cement Chemical composition, % SiO2 Al2O3 Fe2O3 CaO MgO SO3 Na2Oeq I (mean) 20.5 5.4 2.6 63.9 2.1 3.0 0.61 II (mean) 21.2 4.6 3.5 63.8 2.7 0.51 III (mean) 20.6 4.9 2.8 63.4 2.2 0.56 IV (mean) 22.2 5.0 62.5 1.9 0.36 V (mean) 21.9 3.9 4.2 2.3 0.48 White (mean) 22.7 4.1 0.3 66.7 0.9 0.18 Table 2-6. Chemical Composition Cements*

Potential compound composition,% Type of portland cement Potential compound composition,% Blaine fineness m2/kg C3S C2S C3A C4AF I (mean) 54 18 10 8 369 II (mean) 55 19 6 11 377 III (mean) 17 9 548 IV (mean) 42 32 4 15 340 V (mean) 22 13 373 White (mean) 63 1 482 Table 2-6. Compound Composition and Fineness of Cements

Reactivity of Cement Compounds Fig. 2-29. Relative reactivity of cement compounds. The curve labeled “overall” has a composition of 55% C3S, 18% C2S, 10% C3A, and 8% C4AF, an average Type I (Type 10) cement composition (Tennis and Jennings 2000).

Nonevaporable Water Contents Hydrated cement compound Nonevaporable (combined) water content (g water/g cement compound) C3S hydrate 0.24 C2S hydrate 0.21 C3A hydrate 0.40 C4AF hydrate 0.37 Free lime (CaO) 0.33 Table 2-7. Nonevaporable Water Contents for Fully Hydrated Major Compounds of Cement

Fig. 2-30. Cement paste cylinders of equal mass and equal cement content, but mixed with different water to cement ratios, after all water has evaporated from the cylinders. (1072)

Scanning-Electron Micrograph of Powdered Cement Fig. 2-31. Scanning-electron micrograph of powdered cement at 1000X. (69426)

Fineness of Cement ASTM C 204 ASTM C 115 Fig. 2-32. Blaine test apparatus (left) and Wagner turbidimeter (right) for determining the fineness of cement. Wagner fineness values are a little more than half of Blaine values. (40262, 43815)

Cement Fineness CSA Test Method A 456.2-A3 Fig. 2-33. Quick tests, such as washing cement over this 45μm sieve, help monitor cement fineness during production. Shown is a view of the sieve holder with an inset top view of a cement sample on the sieve before washing with water. (68818, 68819)

Particle Size Distribution Fig. 2-34. A laser particle analyzer uses laser diffraction to determine the particle size distribution of fine powders. Fig. 2-31 (right) illustrates typical results. (69390)

Soundness Test CSA A456.2-B5 Fig. 2-35. In the soundness test, 25-mm square bars are exposed to high temperature and pressure in the autoclave to determine the volume stability of the cement paste. (23894)

Consistency of Cement Paste CSA A456.2-B1 Vicat plunger Fig. 2-36. Normal consistency test for paste using the Vicat plunger. (68820)

Consistency of Mortar CSA A456.3 Flow table Fig. 2-37. Consistency test for mortar using the flow table. The mortar is placed in a small brass mould centered on the table (inset). For skin safety the technician wears protective gloves while handling the mortar. After the mould is removed and the table undergoes a succession of drops, the diameter of the pat is measured to determine consistency. (68821, 68822)

Setting Time CSA A456.2-B2 Vicat apparatus Fig. 2-38. Time of set test for paste determined by the Vicat needle. (23890)

Setting Time CSA A456.2-B3 Gillmore needle Fig. 2-39. Time of set as determined by the Gillmore needle. (23892)

Setting Times for Portland Cements Fig. 2-40. Time of set for portland cements (Gebhardt 1995 and PCA 1996).

Mortar Cubes CSA A456.2-C2 Fig. 2-41. 50-mm mortar cubes are cast (left) and crushed (right) to determine strength characteristics of cement. (69128, 69124)

Strength Development of Mortar Cubes Fig. 2-42. Relative strength development of portland cement mortar cubes as a percentage of 28-day strength. Mean values adapted from Gebhardt 1995.

Strength Development Type 10 and 20 Cements Fig. 2-43. Strength development of portland cement mortar cubes from combined statistics. The dashed line represents the mean value and the shaded area the range of values (adapted from Gebhardt 1995).

Strength Development Type 30, 40, and 50 Cements Fig. 2-43. Strength development of portland cement mortar cubes from combined statistics. The dashed line represents the mean value and the shaded area the range of values (adapted from Gebhardt 1995).

Fig. 2-44. Heat of hydration can be determined by CSA A456 Fig. 2-44. Heat of hydration can be determined by CSA A456.2-B7 (ASTM C 186) (68823)

Fig. 2-44. Heat of hydration can be determined by a conduction calorimeter. (68824)

Heat of Hydration at 7 Days Type 10 cement Type 20 cement Type 20 Moderate heat cement Type 30 cement Type 40 cement Type 50 cement % of Type 10 100 99 75 106 67 89 Table 2-8. ASTM C 186 Heat of Hydration for Selected Portland Cements from the 1990s, kJ/kg

Heat Evolution Fig. 2-45. Heat evolution as a function of time for cement paste. Stage 1 is heat of wetting or initial hydrolysis (C3A and C3S hydration). Stage 2 is a dormant period related to initial set. Stage 3 is an accelerated reaction of the hydration products that determines rate of hardening and final set. Stage 4 decelerates formation of hydration products and determines the rate of early strength gain. Stage 5 is a slow, steady formation of hydration products establishing the rate of later strength gain.

Fig. 2-46. Loss on ignition test of cement. CSA A456 Fig. 2-46. Loss on ignition test of cement. CSA A456.1 Chemical Test Methods for Hydraulic Cement, Supplementary Cementing Materials, and Cementitious Hydraulic Slag (43814)

Density of Cement Le Chatelier flask CSA A456.2-A2 Helium pycnometer Fig. 2-47. Density of cement can be determined by (left) using a Le Chatelier flask and kerosine or by (right) using a helium pycnometer. (68825, 68826)

Bulk Density Bulk density of cement varies between 830 kg/m3 and 1650 kg/m3 Fig. 2-48. Both 500-mL beakers contain 500 grams of dry powdered cement. On the left, cement was simply poured into the beaker. On the right, cement was slightly vibrated—imitating consolidation during transport or packing while stored in a silo. The 20% difference in bulk volume demonstrates the need to measure cement by mass instead of volume for batching concrete. (68970)

Thermal Analysis Thermogravimetric analysis (TGA) Differential Thermal Analysis (DTA) Differential Scanning Calorimetry (DSC) Fig. 2-49. Thermal analysis equipment. (69116)

Differential Scanning Calorimetry Thermogram of a Cement Paste after (a) 15 min and (b) 24 h of Hydration Fig. 2-50. Differential scanning calorimetry thermogram of a portland cement paste after (a) 15 minutes and (b) 24 hours of hydration. C = calcium hydroxide; E = ettringite; G = gypsum; and S = syngenite.

Virtual Cement Testing Fig. 2-51. Two-dimensional image of portland cement. Colours are: red–tricalcium silicate, aqua–dicalcium silicate, green– tricalcium aluminate, yellow–tetracalcium aluminoferrite, pale green–gypsum, white–free lime, dark blue–potassium sulphate, and magenta–periclase. The image was obtained by combining a set of SEM backscattered electron and X-ray images (NIST 2001).

Transporting Cement Fig. 2-52. Portland cements are shipped from the plant silos to the user in bulk by (left to right) rail, truck, or water. (59899, 59355, 59891)

Packaging and Storage Fig. 2-53. A small amount of cement is shipped in bags, primarily for mortar applications and for small projects. (59411) Fig. 2-54. When stored on the job, cement should be protected from moisture. (36052)

Videos 1/5 Manufacturing Cement

Videos 2/5 Cement Hydration Soundness

Videos 3/5 Setting Time False Set

Videos 4/5 Cement Hydration Simulation

Videos 5/5 Cement Delivery Storage