1. 1 CONTENTS 1. PORTLAND CEMENT 1.1Oxide Composition of Portland Cement 1.2Compound Composition of Portland Cement 1.3Computation Method of Determining the Compound Composition of Portland Cement 1.4Chemistry of Hydration 2. EVALUATION OF AGGREGATES 2.1Properties Required For Mix Design 2.2Durability of Aggregates 3. ADMIXTURES FOR CONCRETE 3.1Definitions and Classifications 3.2Uses of Admixtures 3.3Air-Entraining Admixtures 3.4Accelerating Admixtures 3.5Retarding Admixtures 3.6Water-Reducing Admixtures 3.7Mineral Admixtures 3.8Miscellaneous Admixtures 4. FRESH CONCRETE 4.1Workability 4.2Setting of Concrete

2. 2 CONTENTS 5. CONCRETE MIX PROPORTIONING 5.1Fundamentals of Mix Design 5.2Background Data For Mix Design 5.3ACI Method of Mix Design 5.4Turkish Standard (TS 802) Method of Concrete Mix Design 6. STRENGTH OF CONCRETE 6.1Nature of Strength 6.2Factors Affecting Strength 6.3Compressive Strength 6.4Review of Compressive Strength Equations 6.5Tensile Strength 7. STRESS-STRAIN RELATIONS AND ELASTIC CONSTANTS 7.1Determination of Modulus of Elasticity 7.2Other Elastic Constants of Concrete 7.3Equations For Estimating the Stress-Strain Curves 8. CURING OF CONCRETE 9. QUALITY CONTROL 9.1Measurement of Variability 9.2Applications to Concrete 9.3ACI Approach to Variability 9.4Quality Control Charts

3. 3 CONTENTS 10. DIMENSIONAL STABILITY OF CONCRETE 10.1Plastic Shrinkage 10.2Drying Shrinkage 10.3Autogenous Shrinkage 10.4Carbonation Shrinkage 10.5Creep 11. DURABILITY OF CONCRETE 11.1Permeability 11.2Leaching and Efflorescence 11.3Sulfate Attack 11.4Acid Attack 11.5Carbonation 11.6Reinforcement Corrosion 11.7Freezing-Thawing 11.8Alkali-Aggregate Reaction 11.9Abrasion

4. 4 REFERENCES 1.) Erdoğan, T.Y., BETON, Metu Press, Ankara 2003. 2.) Neville, A.M., PROPERTIES OF CONCRETE, Longman Group Limited, England, 1995. 3.) Taylor, G.D., MATERIALS OF CONSTRUCTION, Construction Press, London and New York, 1983. 4.) Neville, A.M. and Brooks, J.J., Concrete Technology, Longman Group, 1997, updated. 5) Portland Cement Association, Course Material provided from Dr. Mike Thomas

5. 5 CONCRETE TECHNOLOGY LECTURE NOTES Kambiz RAMYAR, Prof.Dr. Özge ANDİÇ ÇAKIR, Assist. Prof. Dr. CONCRETE TECHNOLOGY

6. Cement Stone or Gravel Sand Water Concrete Concrete Basics

7. 7 PORTLAND CEMENT

8. Concrete Basics Concrete Cement

9. Concrete Basics Cake Flour Cement is to concrete … as flour is to cake!

10. Brief History of Cement 1824 Portland Cement Joseph Aspdin’s patent for portland cement

11. Brief History of Cement Portland Cement Developments since late 1800’s Development of rotary kilns

12. Brief History of Cement Portland Cement Developments since late 1800’s Development of rotary kilns Higher burning temperatures Introduction of ball mills Incorporation of gypsum to control set Introduction of dry process Use of precalciners Improved energy efficiency Improved quality control Wider range of cements – e.g. blended cements Reduced emissions

13. Shorthand Notation + other trace elements OxideShorthandCommon Name CaOClime SiO 2 Ssilica Al 2 O 3 Aalumina Fe 2 O 3 Fferric oxide MgOMmagnesia H2OH2OHwater K2OK2OK alkalis Na 2 ON SO 3 sulfateS CO 2 carbonateC

14. 14 COMPOUND COMPOSITION OF PORTLAND CEMENT The oxides interact with each other in the rotary kiln to form a series of complex compounds. Portland cement clinker is usually regarded as constituted of four major compounds as shown below: Chemical NameChemical FormulaShorthand Notation Mass (%) Tricalcium silicate3CaOSiO 2 C3SC3S50 - 70 Dicalcium silicate2CaO SiO 2 C2SC2S15 - 30 Tricalcium aluminate3CaOAl 2 O 3 C3AC3A 5 - 10 Tetracalcium aluminoferrite 4CaOAl 2 O 3 Fe 2 O 3 C 4 AF 5 - 15 Calcium sulfate dihydrateCaSO 4 2H 2 OCSH 2 ~ 5

15. 020406080100 Time (days) 0 20 40 60 80 100 Degree of Hydration (%) C3AC3A C3SC3S C2SC2S C 4 AF Hydration of Cement Compounds Rate of hydration of cement compounds in portland cement paste (Mindess et al, 2003)

16. Hydration of Cement Compounds 020406080100 Time (days) 0 10 20 30 40 50 Compressive Strength (MPa) 2,000 4,000 6,000 8,000 10,000 0 60 70 Compressive Strength (psi) C 3 A+CSH 2 C 4 AF+CSH 2 C2SC2S C3SC3S Compressive Strength development in pastes of pure cement compounds (Mindess et al, 2003)

17. C3SC3S Tricalcium silicate (alite)  Hydrates & hardens rapidly  Responsible for initial set and early strength C2SC2S Dicalcium silicate (belite)  Hydrates & hardens slowly  Contributes to later age strength (beyond 7 days) C3AC3A Tricalcium aluminate  Liberates a large amount of heat during first few days  Contributes slightly to early strength development  Cements with low %-ages are more resistant to sulfates C 4 AFTetracalcium aluminoferrite (ferrite)  Reduces clinkering temperature  Hydrates rapidly but contributes little to strength  Colour of hydrated cement (gray) due to ferrite hydrates Properties of Cement Compounds

18. Materials of Construction-Cement18 Types of cements, TS EN 197-1 covers 27 standard cements classified into five main types: CEM I Portland cement (ordinary) CEM II Portland composite cement CEM III Blast furnace slag cement CEM IV Pozzolanic cement CEM V Composite cement THE TYPES OF CEMENTS PRODUCED IN TURKEY-CEN Cements

19. Main Constituents of CEN Cements Portland Cement Clinker (K) Granulated blast furnace slag (S) Pozzolanic Materials (P, Q) -Natural pozzolana (P) -Natural calcined pozzolana (Q) Fly ashes (V, W) -Siliceous fly ash (V) reactive CaO<10% by mass -Calcareous fly ash (W) reactive CaO>10% by mass 19

20. Main Constituents of CEN Cements Burnt shale (T) Limestone (L, LL) - LL: total organic matter < 0.20 % by mass - L: total organic matter< 0.50 % by mass Silica fume (D) Minor additional constituents (<5% by mass) 20

21. Materials of Construction-Cement21 Main typeNameSymbol CEM IPortland cementCEM I CEM IIPortland blast furnace slag cementCEM II/A-S CEM II/B-S Blast furnace slag Portland silica fume cementCEM II/A-DSilica fume Portland pozzolan cementCEM II/A-P CEM II/B-P CEM II/A-Q CEM II/B-Q Natural pozzolan Calcined pozzolan Portland fly ash cementCEM II/A-V CEM II/B-V CEM II/A-W CEM II/B-W Low lime fly ash High lime fly ash Portland burned schist cementCEM II/A-T CEM II/B-T Burned schist Portland limestone cementCEM II/A-L CEM II/B-L CEM II/A-LL CEM II/B-LL organic material content<0.5% organic material content<0.2% Portland composite cementCEM II/A-M CEM II/B-M Types of CEN cements

22. Materials of Construction-Cement22 Main typeNameSymbol CEM IIIBlast furnace slag cementCEM III/A CEM III/B CEM III/C CEM IVPozzolanic cementCEM IV/A CEM IV/B CEM VComposite cementCEM V/A CEM V/B In addition to TS EN 197, TS 21 covers “ White portland cement”, TS 22-1 or 2 EN 413-1 or 2 cover “Masonry cement Part 1: “Properties” or Part 2:”Test methods”. Types of CEN cements

23. Materials of Construction-Cement23 Cement typeclinkerSDPQVWTL-LLMinor CEM I95-100 0-5 CEM II/A-S80-946-20 0-5 CEM II/B-S65-7921-35 0-5 CEM II/A-D90-946-10 0-5 CEM II/A-P80-946-20 0-5 CEM II/B-P65-7921-35 0-5 CEM II/A-Q80-946-20 0-5 CEM II/B-Q65-7921-35 0-5 The Composition of TS EN 197-1 Cements Types of CEN cements

24. Materials of Construction-Cement24 Cement typeclinkerSDPQVWTL-LLMinor CEM II/A-V80-946-20 0-5 CEM II/B-V65-7921-35 0-5 CEM II/A-W80-946-20 0-5 CEM II/B-W65-7921-35 0-5 CEM II/A-T80-946-20 0-5 CEM II/B-T65-7921-35 0-5 CEM II/A-L (LL)80-946-20 0-5 CEM II/B-L (LL)65-7921-35 0-5 The Composition of TS EN 197-1 Cements Types of CEN cements

25. Materials of Construction-Cement25 Cement typeclinkerSDPQVWTL-LLMinor CEM II/A-M80-94 6-20 0-5 CEM II/B-M65-79 21-350-5 CEM III/A35-6436-65 0-5 CEM III/B20-3466-80 0-5 CEM III/C5-1981-95 0-5 CEM IV/A65-8911-35 0-5 CEM IV/B45-6436-55 0-5 CEM V/A40-6418-30 0-5 CEM V/B20-3831-50 0-5 The Composition of TS EN 197-1 Cements Types of CEN cements

26. Standard designation for CEN cements Example 1: Portland cement conforming to EN 197-1 of strength class 42.5 with a high early strength is identified by; Portland cement: CEM I 42.5R Example 2: Portland-limestone cement containing between 6% and 20% by mass of limestone with a total organic matter content not exceeding 0.50% by mass (L) of strength class 32.5 with an ordinary early strength is identified by; Portland limestone cement: CEM II A – L 32.5N 26

27. Standard designation for CEN cements Example 3: Portland-composite cement containing in a total quantity of granulated blast furnace slag (S), siliceous fly ash (V) and limestone (L) of between 6% and 20% by mass and strength class 32.5 with a high early strength is identified by; Portland-composite cement: CEM II/A-M(S-V-L) 32.5R Example 4: Composite cement containing between 18% and 30% by mass of granulated blast furnace slag (S) and between 18% and 30% by mass of siliceous fly ash (V) of strength class 32.5 with an ordinary early strength is identified by; Composite cement: CEM V/A (S-V) 32.5 N 27

28. EN 197-1 chemical requirements for cements 28

29. 29 Homework – Remember Bogue’s calculations from Materials of Construction course Two portland cements with the following oxide compositions are available. Compare the cements from following points of view: A) rate of hydration B) heat of hydration C) early cementitious value D) ultimate cementitious value % OxideAB CaO62.861.8 SiO 2 20.421.4 Al 2 O 3 5.2 Fe 2 O 3 3.0 MgO4.0 SO 3 2.5

30. Pozzolanic Reaction Reaction of silica in pozzolan with calcium hydroxide: xCH + yS + zHC x S y H X+Z Hydration Water Calcium-silicate hydrate Calcium hydroxide Silica in pozzolan Additional cementitious C-S-H In alumino-siliceous pozzolans (e.g. fly ash and metakaolin) the alumina also participates in reactions with calcium hydroxide producing various calcium-aluminate hydrates (C-A-H) and calcium-alumino-silicate hydrates (C-A-S-H).

31. 05301261272890 MinutesHoursDays Amount Porosity CH Ettringite C-S-H C-(A,F)-H Monosulfate Hydration Products

32. Anhydrous cement Water Development of Microstructure

33. C-S-H CH Ettringite Development of Microstructure

34. C-S-H CH Ettringite Development of Microstructure

35. C-S-H CH Ettringite Development of Microstructure

36. C-S-H CH Ettringite Development of Microstructure

37. C-S-H CH Monosulfate Development of Microstructure

38. 38 Let us, therefore, consider the hydration of 100 g of cement. Taking the specific gravity of dry cement as 3.15, the absolute volume of unhydrated cement is 100/3.15 = 31.8ml. The non-evaporable water is about 23% of the weight of cement, i.e., 23ml. The solid products of hydration occupy a volume equal to the sum of volumes of anhydrous cement and water less 0.254 of the volume of non-evaporable water, i.e., 31.8 + 0.23[100(1-0.254)] = 48.9ml. Since the paste in this condition has a characteristic porosity of about 28%, the volume of gel water, Wg is given by the following equation. Thus, the volume of hydrated cement is 48.9+19.0 = 67.9 ml.

39. 39 42.0 ml water 31.8 ml cement 5.9 ml empty capillary pores 19.0 ml gel water 48.9 ml solid products of hydration 0% 100% Schematic representation of hydration of cement Summarizing, we have: Weight of dry cement=100 g Absolute volume of dry cement= 31.8 ml. Weight of combined water= 23 g Volume of gel water= 19.0 ml. Total water in the mix= 42.0 ml. W/C (by weight) = 0.42 W/C (by volume) = 1.32. Volume of hydrated cement= 67.9 ml. Original volume of cement + water= 73.8 ml. Decrease in volume due to hydration = 5.9 ml Volume of products of hydration per 1cm 3 of dry cement = 2.1 ml.

40. 40 As a more specific example let us consider the hydration of a paste with W/C = 0.475, sealed in a tube. Let the weight of dry cement be 126 g, which corresponds to 40 ml. The volume of water is then 0.475x126 = 60 ml. Let us now consider the situation when the cement has hydrated fully. The non- evaporable water is 0.23 x 126 = 29 ml. and the gel water Wg is such that Wg/[40+29(l-0.254) + Wg] = 0.28. Thus Wg = 24.0 ml. The volume of hydrated cement is 40 + 29(1-0.254) +24 = 85.6 ml. There is thus 60 - (29+24) = 7 ml water left as capillary water in the paste. In addition, 100 - (85.6 +7) = 7.4 ml form empty capillaries. If the cement is half hydrated, the gel/space ratio becomes:

41. 41 60 ml water 40 ml cement 7.4 ml empty capillary pores 24.0 ml gel water 61.6 ml solid products of hydration 0% 100% 3.7 ml cap. pores 33.5 ml cap. water 30.8 ml solid products of hydration 50% 12 ml gel water 20 ml unhydrated cement 7.0 ml capillary water

42. 100 50 0 020 30405060 Curing time (days) 20 30 40 50 60 Capillary Porosity (%) Degree of Hydration (%) Capillary porosity   Degree of hydration Young et al. 1998 Development of Microstructure

43. 50 40 30 20 10 0 Capillary Porosity (%) 0.300.400.500.600.700.800.90 W/CM 100% Hydration Young et al. 1998

44. 44