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Fly ash in cement and concrete composition

Fly ash in cement and concrete composition. Zbigniew Giergiczny Silesian University of Technology, Gliwice, Poland Technological Center Betotech , Ltd. April , 24–25 2014, Moscow. Subject of presentation. Definition of fly ash Classification of fly ash

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Fly ash in cement and concrete composition

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  1. Flyash in cement and concretecomposition Zbigniew Giergiczny Silesian University of Technology, Gliwice, Poland Technological Center Betotech , Ltd. April, 24–25 2014, Moscow

  2. Subject of presentation • Definition of flyash • Classification of flyash • Flyash as a cement component • Flyash as anadditive for concrete • Summary Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  3. Fly ash – is one of the residues resulted from hard coalorbrowncoaldust combustion in various types offurnacesin the power or heat and powerplants. Flyash FLY ASH Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  4. Fly ash can be classified according to: • chemical composition, • amorphous and crystalline phase content, • fineness (sieve residue), • unburned carbon content (loss on ignition). Classification of fly ash Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  5. FLY ASH CALCAREOUS(siliceous - calcareous) SILICEOUS Classification of fly ash SILICEOUS - ALUMINOUS Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  6. Fly ash as a cement component Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  7. Fly ash according to cementitious standard EN 197-1 • Fly ash is obtained by electrostatic or mechanical precipitation of dust-like particles from the flue gases of furnaces fired with pulverised coal. The ash obtained by other methods should not be used in the cement according to EN 197-1. • Siliceousflyash (V)is a fine powder of mostlysphericalparticleshavingpozzolanicproperties.It consistsessentially of reactivesilicondioxide (SiO2) and aluminium oxide (Al2O3). The remaindercontains iron oxide (Fe2O3) and othercompounds. • Requirements: • reactivecalciumoxide (CaO) max. 10,0 % • reactivesilicondioxidecontent min. 25,0 % • content of loss on ignition (unburned carbon): • cat. A ≤ 5,0 %, • cat. B ≤ 7,0 %, • cat. C ≤ 9,0 %. Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  8. Spherical grains of a high content of the glassy phase • High fineness (specific surface area from 250.0 to 450.0 m2/kg) • Pozzolanicproperties Siliceous fly ash (V) Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  9. Calcareous fly ash (W) • Very fine powder having pozzolanic properties and/orhydraulic, • It consists of reactive calciumoxide (CaO ≥ 10 %), silicon dioxide (SiO2) and aluminium oxide (Al2O3). The remainder contains iron oxide (Fe2O3) and other compounds, • It containsmorephasesthansiliceousflyash. Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  10. POZZOLAN-HYDRAULIC ACTIVITY OF CALCAREOUS FLY ASH FROM CONVENTIONAL FURNACES Time of hydration [days] 70 % of siliceousflyash (specificsurface 540[m2/kg] 70 % of calcareousflyash (specificsurface 556[m2/kg] Fly ash with high content of calcium compounds Compressivestrength [MPa] A1 – unground ash A2 – ground ash Time [days] Temperature [°C] Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  11. Characteristics of fly ash Morphology of fly ashgrains calcareoussiliceous Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  12. Commoncementscontainflyash as a main component 1)Most often this type of cement includes fly ash and blastfurnace slag, but also may include pozzolan, silica fume,burntshaleand ground limestone. 2)The cement includes usually a mixture of pozzolans and fly ash or fly ash. 3) The cement includespozzolans, blastfurnaceslag and siliceousflyash. Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  13. Properties of cements containing fly ash Setting time of CEM II/B-V 32,5R depending on ambient temperature Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  14. Properties of cements containing fly ash Increase of compressive strength Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  15. Compressive strength development of cements(standard mortars) Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  16. hydratedcalciumsilicates(C-S-H) hydratedcalciumaluminates hydratedcalciumsulfoaluminate FLY ASH(reactive SiO2 and Al2O3) Ca(OH)2 H2O Pozzolanic reaction rate depends on: • chemical and mineral composition of fly ash, • temperature and time of reaction, • pressure, • amountof water, • fly ash /Ca(OH)2 ratio, • fly ash specific surface, • presenceof chemical admixtures Pozzolanicactivity Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  17. Amount of Ca(OH)2 in hardened cement paste Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  18. Permeability of concrete CEM III/A 32,5N CEM I 32,5R CEM II/B-S 32,5R CEM II/B-V 32,5R Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  19. Chemical composition of calcareousfly ash Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  20. Phase composition of calcareous fly ash Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  21. Pozzolanic activity of mineraladditives + - ground components Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  22. Compressive strength of Portland – composite cement - cements industrially produced Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  23. Productionscheme of CEM II/B-M (V-W) 32,5R Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  24. Compressive strength of CEM II/B-M(V-W) 32,5R Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  25. Results of conductedresearch Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  26. SILICEOUS FLY ASH AS A CONCRETE COMPONENT

  27. Chemicalcomposition of fly ash according to EN 450-1 Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  28. Phisicalproperties of fly ashaccording to EN 450-1 Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  29. Requirements set against fly ashin the standards ASTM and CAN-CSA Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  30. FlyashFlyashLoss on ignotion – 1,79 % - categoryA Loss on ignotion – 8,48 % - category CFineness – 1,0 % - categoryS Fineness – 27,5 % - category N Microscope image of fly ash Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  31. Correlation of waterdemandand fineness of fly ashwith similar loss on ignition (4,78% and 4,99%) Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  32. Correlation of waterdemandand loss on ignitionof fly ash with similar fineness (30,6% and 29,8%) Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  33. Flyash with different contents of loss on ignition (unburned carbon) Fly ash – loss on ignition 17,9% Fly ash – loss on ignition 2,2% Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  34. Effect offly ash particle size on the amountin concrete mixing water at constant consistence [acc. Lindon K.A. Sear] Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  35. Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  36. Lower total porosity Lower share of the capillary pores Larger share of the gelpores Microstructure Concrete with the addition of fly ash Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  37. The diffusion coefficient of chloride ions in the concrete with fly ash and slag cements Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  38. Frost resistance of concrete (F150); start test after 28, 56 and 90days Cement (30% of flyash); 350 kg/m3; w/c = 0.5 Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  39. The change in temperature inside of the concrete block(volume 15 m3) Zbigniew Giergiczny. V International Conference ASHES FROM TPPS

  40. Conclusions • Fly ash, as a by-product of coal combustion, is an interesting mineral additive which should be widely applied in industrial practice, specially, in the production of cement and concrete • Used in the production of cement and concrete shall comply with the following standards: • PN-EN 197-1 „Cement — Part 1: Composition, specificationsand conformity criteria for common cements” • PN-EN 450 „Fly ash for concrete — Part 1: Definition, specificationsand conformity criteria” • Fly ash applied in the above technologies should be characterized by: homogeneity, stability of physical characteristics, appropriate activity and spherical shape of the grains

  41. Thank you for your attention

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