1. CEMENT AND CONCRETE MATERIALS materials fundamentals + mix design Christopher Hall 2009 S131 christopher.hall@ed.ac.uk

2. CEMENT Materials fundamentals Sources of information Cement manufacture + composition Cement hydration Microstructure Concrete mixes Properties: strength permeability durability

3. Information/texts Jackson & Dhir: Civil Engineering Materials, 5th edn, 1997 Mindess, Young & Darwin: Concrete, 2002 Neville & Brooks: Concrete Technology, 1987 Neville: Properties of Concrete, 4th edn, 1995 Bensted & Barnes: Structure and Performance of Cements, 2nd edn, 2001

4. Information/journals Cement and Concrete Research Magazine of Concrete Research American Concrete Institute Journal ACI Journal Materials and Structures [RILEM]

5. Information/websites Virtual Cement & Concrete Testing Laboratory includes Electronic monograph from Bentz at NIST: http://ciks.cbt.nist.gov/vcctl/ See also microstructure images library from Lange at UIUC: https://netfiles.uiuc.edu/dlange/www/CML

6. Cement Manufacture Raw materials limestone + clay on firing, produces a complex mixture of synthetic minerals, principally calcium silicates and calcium aluminates

7. Manufacture

8. CEMENT World production 2001 1.6 billion tons

9. CEMENT World production 2001 1.6 billion tons Steel production 900 million tons

10. CEMENT World production 2001 1.6 billion tonnes 2--5 % total CO 2 emission Energy intensive manufacture Various figures are quoted. The energy cost of manufacture is around 3500 kJ/kg cement

11. CEMENT World production 2001 1.6 billion tonnes EU production 2002 194 million tonnes For each tonne cement produced 0.800 tonne CO 2 is also produced 0.525 tonne from decalcination of limestone 0.335 tonne from combustion of fuel in the kiln 0.050 tonne from electricity production

12. CEMENT In EU, cement industry produces 3 per cent of total anthropogenic CO 2 Source: Cembureau

13. CEMENT COMPOSITIONS CaO SiO 2 Al 2 O 3  Fe 2 O 3 OPC zone

14. CEMENT COMPOSITION Notation CaO Al 2 O 3 Fe 2 O 3 SiO 2

15. CEMENT COMPOSITION Notation CaO C Al 2 O 3 A Fe 2 O 3 F SiO 2 S

16. CEMENT COMPOSITION Notation CaO C Al 2 O 3 A Fe 2 O 3 F SiO 2 S

17. Clinker microstructure C 3 S C 2 S C 3 A C 4 AF 150 micron C3SC3S C2SC2S

18. Clinker microstructure C 3 S C 2 S C 3 A C 4 AF 150 micron C3SC3S C2SC2S

19. Clinker microstructure C 3 S C 2 S C 3 A C 4 AF 150 micron C3SC3S C2SC2S

20. Clinker microstructure C 3 S C 2 S C 2 A C 4 AF C 3 A C 4 AF

21. C 3 A C 4 AF

22. Clinker microstructure C 3 S, C 2 S, C 3 A, C 4 AF 200 micron

23. Cement grinding Gypsum additions (strictly sulphate) Particle size distribution Images from Lange UIUC http://cee.ce.uiuc.edu/lange/micro

24. Cement hydration 1 Heat evolution Induction period

25. Cement hydration 2 Chemical reaction with water All minerals involved 115 micron

26. Cement hydration 2 Principal reaction which develops strength C 3 S + water ---> C-S-H

27. Cement hydration 3 Chemical reaction with water All minerals involved Formation of lime (calcium hydroxide) pH of pore water

28. Cement hydration 4 Water requirement about 30% by wt cement for complete reaction

29. Cement hydration 5 Four stages of hydration in a microstructural model of C 3 S hydration. The degrees of hydration are: top left--0% top right--20%, bottom left--50% bottom right--87% Red=unreacted cement blue=CH yellow=C-S-H black= porosity from Bentz, NIST

30. Computational materials science Cellular automaton model of cement and concrete D Bentz and E Garboczi NIST

31. Cement hydration 6 Synchrotron X-ray view

32. Summary of setting and hardening Workability Development of continuous network of hydrate material Strength development Porosity and permeability Timescale

33. Strength and strength development

34. Cement Based Materials Mortars Concrete Manufactured cement based materials Autoclaved aerated concrete

35. Transport properties Permeability Sorptivity see Hall & Hoff: Water Transport in Brick, Stone and Concrete 2002

36. PERMEABILITY property Darcy’s law: u = Q/A = -  k  p /L k permeability Q volume rate of flow

37. A B

38. Types of cements Portland cement Blended or composite cements Portland + other mineral components

39. BS EN 197-1 Cement Other mineral components are Minerals which react with lime Pozzolans Blastfurnace slag Fly ash Natural pozzolans Inert fillers Crushed limestone

40. BS EN 197-1 Cement