pc cement hydration. introduction portland cement concrete continous binder phase: the cementitious...
TRANSCRIPT
![Page 1: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/1.jpg)
PC Cement Hydration
![Page 2: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/2.jpg)
Introduction
Portland Cement ConcreteContinous binder phase: the cementitious matrix
•Binder effect on PCC behaviorAffects permeabilityAffects strength
Dispersed particulate phase: the aggregates•Coarse: #4 to 1½”•Fine: #100 to #4•Aggregates have a major effect on PCC behavior
Serve as a fillerIncrease concrete modulus of elasticity
![Page 3: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/3.jpg)
Cementitious Phase
•Portland Cement•Water•Admixtures
LiquidMineral
}
Workability & Strength
![Page 4: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/4.jpg)
![Page 5: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/5.jpg)
Cement Manufacture
•Quarrying – Raw materials •Crushing•Grinding •Mixing•Calcinated (1100C)•Burned (1450C)•Clinker is produced (10 mm size)•Inter-ground with 5% gypsum (1-100 m)
- most reactive ( <50 m)
![Page 6: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/6.jpg)
Hydration process
![Page 7: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/7.jpg)
Hydration process
Setting – Solidification of the plastic cement paste
•Initial set – beginning of solidification – Paste become unworkable – loss in consistency - not < 45 min.
•Final set – Time taken to solidify completely – Not > 375min.
Hardening – Strength gain with time – after final set
![Page 8: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/8.jpg)
2C3S + 11H C3S2H8 + 3CH H = -500 J/g
2C2S + 9H C3S2H8 + CH H = -250 J/g
Calcium silicates (C3S or C2S) + water Calcium silicates hydrate (C-S-H) + calcium hydroxide
•Amount of CH depends on proportion of C3S and C2S•CSH - amorphous in nature, is an inexact composition,and is extremely fine (Colloidal).
Hydration - Exothermic Reaction
![Page 9: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/9.jpg)
Tricalcium Aluminate (C3A)C3A + H2O reacts very fastC3A + H2O + CSH2 (Gypsum) reacts much slowerC3A + 3CSH2 + 26H C6AS3H32 H = -1350 J/g
Tricalcium Aluminate + Gypsum + Water Ettringite (product #3)
Once CSH2 is depleted:C6AS3H32 + 2C3A + 4H 3C4ASH12
Ettringite + Tricalcium Aluminate + Water Monosulfoaluminate (product #4)
![Page 10: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/10.jpg)
Ferrite Phase: C4AF
•Forms same reaction as C3A but to a lesser degree•Uses small amount of gypsum
C4AF + 2CH + 14H C4(A,F)H13 + (A,F)H3
Ferrite + Calcium Hydroxide + Water Tetracalcium Hydrate + Ferric Aluminum Hydroxide
(product #5) (product #6)like monosulfoaluminate amorphous
![Page 11: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/11.jpg)
Hydration of Portland cement
Sequence of overlapping chemical reactions
Hydration reactions of individual clinker mineral proceed simultaneously at differing rates and influence each other
A complex dissolution and precipitation process
Leading to continuous cement paste stiffening and hardening
![Page 12: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/12.jpg)
Reaction rate: C3A > C3S > C4AF > C2S
![Page 13: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/13.jpg)
Hydration of Portland cement
Reactivity
•Crystal size – Heating rate, burning temp.
•Crystal defects vs. impurities
•polymorphic form – rate of cooling
•Fineness
e.g. C3S and C2S with impurities hydrate faster than their pure forms
![Page 14: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/14.jpg)
![Page 15: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/15.jpg)
Heat of hydration (Cal/g)
Compound 3 days 90 days 13 years
C3S 58 104 122
C2S 12 42 59
C3A 212 311 324
C4AF 69 98 102
![Page 16: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/16.jpg)
![Page 17: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/17.jpg)
![Page 18: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/18.jpg)
![Page 19: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/19.jpg)
![Page 20: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/20.jpg)
![Page 21: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/21.jpg)
Model of CSH
![Page 22: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/22.jpg)
![Page 23: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/23.jpg)
![Page 24: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/24.jpg)
![Page 25: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/25.jpg)
ASTM Types of Portland Cements
I II III IV VC3S 50 45 60 25 40C2S 25 30 15 50 40C3A 12 7 10 5 4C4AF 8 12 8 12 10Gypsum 5 5 5 4 4
Fineness350 350 450 300 350(m2/kg)
CCS (psi) 1000 900 2000 450 900
Heat of 330 250 500 210 250Hydration(J/g)
![Page 26: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/26.jpg)
![Page 27: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/27.jpg)
I II III IV V
C3S 50 45 60 25 40
C2S 25 30 15 50 40
C3A 12 7 10 5 4
C4AF 8 12 8 12 10
Fine 350 350 450 300 350
![Page 28: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/28.jpg)
![Page 29: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/29.jpg)
![Page 30: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/30.jpg)
Blended Cements
•20 to 70% of total binding material•Total = Cement & supplementary cementitious material•Most mineral admixtures are industrial by products•Use is economical, ecological, or technical in nature
Fly ash: coal fired power plantsBlast furnace slag: steel production
•lower heat, improved durability• Fine pore structure and lower permeability with same w/c•Improve workability
![Page 31: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/31.jpg)
Pozzolans
2S + 3CH + 7H C3S2H8
•First used by Romans•CSH is of lower CaO content•Low heat and slow strength gain•Similar to increase in C2S•Reactivity based on surface area (silica fume)•Some contain alumina (can present durability problems)•Crystalline compounds (quartz); acts to dilutents•Unburned carbon may affect air entrainment•Can have a wide range of composition and reactivity
![Page 32: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/32.jpg)
Blast Furnace Slag
•Rapidly cooled slags - to prevent crystallization•(CSA)glass + H C3(SiA)2H8 (self - reacting)•Forms alumin substituted CSH•Presence of CH accelerated reaction•Mixed with cement
![Page 33: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/33.jpg)
Porosity and pore structure
![Page 34: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/34.jpg)
Capillary pores
Gel pores
![Page 35: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/35.jpg)
Pore size distribution
2.5 nm
![Page 36: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/36.jpg)
![Page 37: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/37.jpg)
![Page 38: PC Cement Hydration. Introduction Portland Cement Concrete Continous binder phase: the cementitious matrix Binder effect on PCC behavior Affects permeability](https://reader035.vdocuments.us/reader035/viewer/2022062308/56649ca45503460f94964a1e/html5/thumbnails/38.jpg)
High strength and low permeability concrete
• Low W/C ratioProper mixture proportioningUse of superplasticizersUse of pozzolans
•High degree of hydrationGood curing