Portland Cement Concrete
CIVE 202 – Construction Materials
Portland Cement Concrete
CIVE 202 – Construction Materials
Pet Peeve #1
CEMENT = CONCRETE
Birthday XXXX Flour Cake
CIVE 202 – Construction Materials
Pet Peeve #1
CEMENT = CONCRETE
CIVE 202 – Construction Materials
Pet Peeve #1
CIVE 202 – Construction Materials
Pet Peeve #2
Concrete “Hardens as it Dries”
CIVE 202 – Construction Materials
Pet Peeve #3
Concrete Won’t Harden Under Water
CIVE 202 – Construction Materials
Pet Peeve #4
Concrete Lasts Forever
CIVE 202 – Construction Materials
Pet Peeve #5
fc´
CIVE 202 – Construction Materials
Pet Peeve #6
The “Structural Failure” y Fallacy
CIVE 202 – Construction Materials
Pet Peeve #7
Tradition
CIVE 202 – Construction Materials
A young woman was preparing a ham for dinner. After she cut off the end of the ham, she placed it in a pan for baking. Upon seeing her do this, her husband asked her, “Why did you cut off the end of the ham?” She replied. “I really don’t know but my mother always did, so I thought you were supposed to.” Later, when talking to her mother, she asked her why she cut the end off the ham before baking it. Her mother replied, “I really don’t know but that’s the way my mom always did it.” A few weeks later, while visiting her grandmother, the young woman asked, “Grandma, why is it that you cut off the end of a ham before you bake it?” Her grandmother replied, “Well dear, otherwise it would never fit into my baking pan.”
CIVE 202 – Construction Materials
Portland Cement Concrete
CIVE 202 – Construction Materials
Portland Cement Concrete Introduction
Concrete is a particulate composite consisting of dispersed particles (aggregates) surrounded and bound together by a continuous matrix (hydrated cement paste). Concrete the most heavily used man-made material in the world. “Twice as much concrete is used in construction around the world than the total of all other building materials combined.” Cement Association of Canada (2006) ( )
Concrete exhibits three distinct phases: Hydrated Cement Paste (hcp) Aggregates Interfacial Transition Zone (ITZ)
CIVE 202 – Construction Materials
Portland Cement Concrete Introduction
Ingredients: - Portland Cement - Water - Aggregates - Admixtures - SCMs Important Terms: Paste = cement + water Mortar = paste + fine aggregate Concrete = mortar + coarse aggregate
CIVE 202 – Construction Materials
Portland Cement Concrete Cement Production
Raw Materials Processing Firing
Limestone,, Sand,, Clay, y, Iron Ore Quarrying, Crushing, Mixing
Calcined & Burned @ 1450 oC Produces Clinker (~10 mm)
Gypsum
Grinding
Size 1 - 100 µm (Average 10 µm)
Portland Cement
CIVE 202 – Construction Materials
Portland Cement Concrete Cement Chemistry Shorthand
Formulae are written as combinations of oxides, which are given the following symbols:
CaO = C
SiO2 = S
Al2O3 = A
Fe2O3 = F
_ SO3 = S
H2O = H
CIVE 202 – Construction Materials
Portland Cement Concrete Cement Composition
Compound
Formula
Shorthand
Fraction*
Tricalcium Silicate
Ca3SiO5
C 3S
55
Dicalcium Silicate
Ca2SiO4
C 2S
20
Tricalcium Al i t Aluminate
Ca3Al2O6
C 3A
10
Tetracalcium Aluminoferrite
Ca4Al2Fe2O10
C4AF
8
Gypsum
CaSO4 · 2H2O
_ CSH2
5
* - Type 10 Ordinary Portland Cement
CIVE 202 – Construction Materials
Portland Cement Concrete Cement Composition
Compound
Primary Effect
Tricalcium Silicate
Early Strength
Dicalcium Silicate
Ultimate Strength
Tricalcium Al i t Aluminate
Flux,, Fast Set,, Sulfate Reactive
Tetracalcium Aluminoferrite
Flux
Gypsum
Prevents Fast Set Flux - Reduces Clinkering Temperature
CIVE 202 – Construction Materials
Portland Cement Concrete Hydration
A chemical reaction between the various cement components and water water. Calcium Silicates (C3S, C2S): 2C3S + 7H → C3S2H8 + 3CH + Heat 2C2S + 5H → C3S2H8 + CH + Heat C-S-H In General: Calcium Silicates + Water → Calcium Silicate Hydrate + Calcium Hydroxide
CIVE 202 – Construction Materials
Portland Cement Concrete Hydration
Tricalcium Aluminate ((C3A): ) _ _ C3A + 3CSH2 + 26H → C6AS3H32 + Heat Gypsum
Ettringite
_ _ C6AS3H32 + 2C3A + 4H → 3C4ASH12 + Heat Monosulfoaluminate In General: Tricalcium Aluminate + Gypsum + Water → Ettringite Ettringite + Tricalcium Aluminate + Water → Monosulfoaluminate
CIVE 202 – Construction Materials
Portland Cement Concrete Hydration
Tetracalcium Aluminoferrite ((C4AF): ) C4AF + 2CH + 14H → C4(A,F)H13 + (A,F)H3
In General: T t Tetracalcium l i Al i f it + Calcium Aluminoferrite C l i H Hydroxide d id + W Water t → Tetracalcium Aluminate Hydrate + Ferric-Aluminum Hydroxide
CIVE 202 – Construction Materials
Portland Cement Concrete Hydration Rates
CIVE 202 – Construction Materials
Portland Cement Concrete Heat Generation
CIVE 202 – Construction Materials
Portland Cement Concrete Reaction Product Generation
CIVE 202 – Construction Materials
Portland Cement Concrete Reaction Product Generation
7 Days
15 Days
CIVE 202 – Construction Materials
Portland Cement Concrete Introduction
Hydration of Cement Paste
27.6 MPa 3.5 MPa
CIVE 202 – Construction Materials
Portland Cement Concrete Microstructure
CIVE 202 – Construction Materials
Portland Cement Concrete Microstructure
CIVE 202 – Construction Materials
Portland Cement Concrete Microstructure
CIVE 202 – Construction Materials
Portland Cement Concrete Microstructure
CIVE 202 – Construction Materials
Portland Cement Concrete Microstructure
CIVE 202 – Construction Materials
Portland Cement Concrete Microstructure - Porosity
The proportion of the total volume of an object not occupied by solid material material.
Macropores > 100 nm Mesopores 2.5 nm - 100 nm Micropores
Portland Cement Concrete
CIVE 202 – Construction Materials
Pet Peeve #1
CEMENT = CONCRETE
Birthday XXXX Flour Cake
CIVE 202 – Construction Materials
Pet Peeve #1
CEMENT = CONCRETE
CIVE 202 – Construction Materials
Pet Peeve #1
CIVE 202 – Construction Materials
Pet Peeve #2
Concrete “Hardens as it Dries”
CIVE 202 – Construction Materials
Pet Peeve #3
Concrete Won’t Harden Under Water
CIVE 202 – Construction Materials
Pet Peeve #4
Concrete Lasts Forever
CIVE 202 – Construction Materials
Pet Peeve #5
fc´
CIVE 202 – Construction Materials
Pet Peeve #6
The “Structural Failure” y Fallacy
CIVE 202 – Construction Materials
Pet Peeve #7
Tradition
CIVE 202 – Construction Materials
A young woman was preparing a ham for dinner. After she cut off the end of the ham, she placed it in a pan for baking. Upon seeing her do this, her husband asked her, “Why did you cut off the end of the ham?” She replied. “I really don’t know but my mother always did, so I thought you were supposed to.” Later, when talking to her mother, she asked her why she cut the end off the ham before baking it. Her mother replied, “I really don’t know but that’s the way my mom always did it.” A few weeks later, while visiting her grandmother, the young woman asked, “Grandma, why is it that you cut off the end of a ham before you bake it?” Her grandmother replied, “Well dear, otherwise it would never fit into my baking pan.”
CIVE 202 – Construction Materials
Portland Cement Concrete
CIVE 202 – Construction Materials
Portland Cement Concrete Introduction
Concrete is a particulate composite consisting of dispersed particles (aggregates) surrounded and bound together by a continuous matrix (hydrated cement paste). Concrete the most heavily used man-made material in the world. “Twice as much concrete is used in construction around the world than the total of all other building materials combined.” Cement Association of Canada (2006) ( )
Concrete exhibits three distinct phases: Hydrated Cement Paste (hcp) Aggregates Interfacial Transition Zone (ITZ)
CIVE 202 – Construction Materials
Portland Cement Concrete Introduction
Ingredients: - Portland Cement - Water - Aggregates - Admixtures - SCMs Important Terms: Paste = cement + water Mortar = paste + fine aggregate Concrete = mortar + coarse aggregate
CIVE 202 – Construction Materials
Portland Cement Concrete Cement Production
Raw Materials Processing Firing
Limestone,, Sand,, Clay, y, Iron Ore Quarrying, Crushing, Mixing
Calcined & Burned @ 1450 oC Produces Clinker (~10 mm)
Gypsum
Grinding
Size 1 - 100 µm (Average 10 µm)
Portland Cement
CIVE 202 – Construction Materials
Portland Cement Concrete Cement Chemistry Shorthand
Formulae are written as combinations of oxides, which are given the following symbols:
CaO = C
SiO2 = S
Al2O3 = A
Fe2O3 = F
_ SO3 = S
H2O = H
CIVE 202 – Construction Materials
Portland Cement Concrete Cement Composition
Compound
Formula
Shorthand
Fraction*
Tricalcium Silicate
Ca3SiO5
C 3S
55
Dicalcium Silicate
Ca2SiO4
C 2S
20
Tricalcium Al i t Aluminate
Ca3Al2O6
C 3A
10
Tetracalcium Aluminoferrite
Ca4Al2Fe2O10
C4AF
8
Gypsum
CaSO4 · 2H2O
_ CSH2
5
* - Type 10 Ordinary Portland Cement
CIVE 202 – Construction Materials
Portland Cement Concrete Cement Composition
Compound
Primary Effect
Tricalcium Silicate
Early Strength
Dicalcium Silicate
Ultimate Strength
Tricalcium Al i t Aluminate
Flux,, Fast Set,, Sulfate Reactive
Tetracalcium Aluminoferrite
Flux
Gypsum
Prevents Fast Set Flux - Reduces Clinkering Temperature
CIVE 202 – Construction Materials
Portland Cement Concrete Hydration
A chemical reaction between the various cement components and water water. Calcium Silicates (C3S, C2S): 2C3S + 7H → C3S2H8 + 3CH + Heat 2C2S + 5H → C3S2H8 + CH + Heat C-S-H In General: Calcium Silicates + Water → Calcium Silicate Hydrate + Calcium Hydroxide
CIVE 202 – Construction Materials
Portland Cement Concrete Hydration
Tricalcium Aluminate ((C3A): ) _ _ C3A + 3CSH2 + 26H → C6AS3H32 + Heat Gypsum
Ettringite
_ _ C6AS3H32 + 2C3A + 4H → 3C4ASH12 + Heat Monosulfoaluminate In General: Tricalcium Aluminate + Gypsum + Water → Ettringite Ettringite + Tricalcium Aluminate + Water → Monosulfoaluminate
CIVE 202 – Construction Materials
Portland Cement Concrete Hydration
Tetracalcium Aluminoferrite ((C4AF): ) C4AF + 2CH + 14H → C4(A,F)H13 + (A,F)H3
In General: T t Tetracalcium l i Al i f it + Calcium Aluminoferrite C l i H Hydroxide d id + W Water t → Tetracalcium Aluminate Hydrate + Ferric-Aluminum Hydroxide
CIVE 202 – Construction Materials
Portland Cement Concrete Hydration Rates
CIVE 202 – Construction Materials
Portland Cement Concrete Heat Generation
CIVE 202 – Construction Materials
Portland Cement Concrete Reaction Product Generation
CIVE 202 – Construction Materials
Portland Cement Concrete Reaction Product Generation
7 Days
15 Days
CIVE 202 – Construction Materials
Portland Cement Concrete Introduction
Hydration of Cement Paste
27.6 MPa 3.5 MPa
CIVE 202 – Construction Materials
Portland Cement Concrete Microstructure
CIVE 202 – Construction Materials
Portland Cement Concrete Microstructure
CIVE 202 – Construction Materials
Portland Cement Concrete Microstructure
CIVE 202 – Construction Materials
Portland Cement Concrete Microstructure
CIVE 202 – Construction Materials
Portland Cement Concrete Microstructure
CIVE 202 – Construction Materials
Portland Cement Concrete Microstructure - Porosity
The proportion of the total volume of an object not occupied by solid material material.
Macropores > 100 nm Mesopores 2.5 nm - 100 nm Micropores
