Transcript NCDOT Concrete School CEMENT

Portland Cement
Joe Diedrich
Technical Services
Manager
Beginning of the Industry
• Portland cement was
first patented in 1824
• Named after the
natural limestone
quarried on the Isle of
Portland in the English
Channel
Portland cement first production
dates in the US and Canada.
• North America - 1871
Coplay, Pennsylvania
• Canada – 1889
Hull, Quebec
Manufacturing of cement starts at the
quarry
Stone is first reduced to
5-inch size, then to
3/4 inch, and stored
Dry process of raw mix preparation
Raw mix changes chemically into
clinker
Clinker
Gypsum
Clinker is ground with gypsum into portland
cement & shipped
Cement recipe
• Limestone – CaO
• Sand – SiO2
• Clay and/or Shale – Al2O3
• Iron Ore or Mill Scale – Fe2O3
• Gypsum
ASTM
C 150
Major Phases of Cement
Components
Alite = impure tricalcium silicate (C3S)
50%
Belite = impure dicalcium silicate (C2S) 25%
Aluminate = tricalcium aluminate (C3A) 8%
Ferrite = tetracalcium aluminoferrite (C4AF) 12%
Hydration of the cement compounds
Compound
Reaction
Rate
Strength
Contribution
Heat
Contribution
C3S
Moderate
High Early
High
C2S
Slow
High Later
Low
C3A
Fast
Low
Very High
Moderate
Low
Moderate
C4AF
Portland cement hydration
Hydration
• Hydration definition:
– The formation of a compound by the combining of
water with some other substance; in concrete, the
chemical reaction between hydraulic cement and
water
The primary product of the reaction
between cement and water:
Calcium Silicate Hydrate (C-S-H gel)
Calcium
Concrete
Silicate
Strength
Hydrate
Happens
Calcium Hydroxide
• A secondary product of the reaction between cement
and water.
• Calcium hydroxide is not a binder. It is a water soluble
compound that takes up space and serves no useful
purpose. Calcium hydroxide can contribute to problems
such as sulfate attack
Types of AASHTO M85 and
ASTM C150 portland cement
•
•
•
•
Type I
Type IA
Type II (MS)
Type II MH
• Type III
• Type IV
• Type V
normal, general-purpose cement
normal, air-entraining
moderate sulfate resistance
moderate sulfate resistance and
moderate heat of hydration
high early strength
(Typically Type I ground 50% finer)
low heat of hydration
(very uncommon)
high sulfate resistance
What is the difference between
Type I and Type II?
• Type I has no C3A limit, however, a Type II is limited to a maximum of 8% C3A
• There is no such thing as a Type I/II cement.
• This is slang terminology for a product that meets criteria for both Types.
Type II & Type V
Sulfate Resistant
Cements
What’s the difference between a Type II
and a Type V?
• Type V has different limitations on the aluminum and iron.
• One of the main differences is a lower maximum C3A.
• Type V has a maximum limitation on the combination of the iron
and aluminum compounds.
Performance of Concretes with Different W/CRatios in Sulfate Soil
Outdoor Sulfate Test
Type V Cement
W/C-ratio = 0.65
Type V Cement
W/C-ratio = 0.39
Type II Moderate Heat Cements
What’s the difference between a Type
II and a Type II MH?
Type II MH has a restriction on the combination of C3S and C3A which are related
to heat generation.
What’s the difference between a Type
II and a Type II MH?
Type II MH has a maximum Blaine of 4300, however if the C3S 4.75(C3A) ≤ 90, this Blaine
restriction does not apply.
Type II MH has a lower 3 day and 7 day minimum strength that apply when the optional
heat of hydration requirement is specified.
Type III
High Early
Strength
Cements
What is different about a
Type III?
•
•
Type III cements have a higher SO3 maximum limit because of their fineness.
Type III cements also have a higher maximum C3A limit.
White Portland
Cement
Blended Hydraulic Cements
ASTM C 595 & AASHTO M-240
• Type IS(X) Portland blast-furnace slag cement
• can include between 0% and 95% ground granulated blast
furnace slag, encompassing old Types IS, I(SM), and S
• Type IP(X) Portland pozzolan cement
• can include between 0% and 40% pozzolan, encompassing
old Types IP and I(PM)
 The letter “X” stands for the nominal percentage of
the SCM included in the blended cement
2009 Cement Specs Update
Ternary Blended Cements
• New Type IT
• 1 slag and 1 pozzolan or 2 pozzolans
• Same chemical and physical limits for
ternary blended cements as for binary
blended cements (IP or IS) with the
same predominant SCM
• Amount and type of SCMs used in
nomenclature
2009 Cement Specs Update
Ternary Blended Cements
• Nomenclature
Format: Type IT(AX)(BY)
Where A and B are SCM types and X and Y
are amounts
• S=slag or P=pozzolan
• Primary (highest content) SCM listed first
• If X=Y requirements of Type IT(P>S) apply
(Type IP)
• Example: Type IT(S25)(P15) contains
25% slag and 15% pozzolan
2009 Cement Specs Update
Ternary Blended Cements
• Since Type IT(S25)(P15) has more slag
than pozzolan, requirements are the
same as Type IS(25)
• Type IT can meet MS, HS, or LH
options
Understanding a Cement
Mill
Test Report
4 main parts of
Cement mill test
report
Plant and
Production Info
Chemical Data
Physical Data
General Info
Understanding a Cement Mill Test
Report
• Cement Identification
• Plant
• Production Date & Silo Information
Cement Mill Test Information
• Chemical and Compound Information
• Specification Limits and Type
Cement Mill Test Physical Data
• Physical Test Data
Cement Mill Test Report –
Specification Type Required
• Report Identifies what cement type it will
meet
NCDOT Portland Cement
Requirements
• NCDOT requires cement information when
submittal of Form 312 identifying source
and type of cement
• Maintain a current cement mill test report
on hand
• Verify before and during the project the
cement source based upon what is
identified with each Bill of Lading (BOL)
which should match Form 312
NCDOT Form 312
FORM 312U
North Carolina Department of Transportation, Division of Highways, Materials and Tests Unit
Statement of Concrete Mix Design and Source of Materials
Contract
Plant Standard
County
New Hanover
Resident Engr.
Class of
B Non-Vib
Concrete
Mix Design No.
P17BNV8
Note Mix Design Units (US or
Metric)
Concrete Producer
Plant Location & DOT
No.
Contractor
Date
S&W Ready Mix Concrete,
Co.
Castle Hayne RM323
3/10/10
Contractor’s Signature
US
Mix Design Proportions Based on SSD Mass of Aggregates
Material
Producer
Source
Cement Type I/II L.A.
Cementos Argos
Pozzolan Flyash Class F
Fine Aggregate
Coarse Aggregate
Other Aggregate
Total Water
Air Entraining Agent
Retarder
Water Reducer
Superplasticizer
Corrosion Inhibitor
Other
The SEFA Group
American Materials Co.
Martin Marietta Aggregates
Colclinker, Cartagena
Columbia
Georgetown, SC
Ivanhoe Pit
Lemon Springs Quarry
BASF Admixtures
BASF Admixtures
BASF Admixtures
Ground Well
Micro Air
Pozzolith 200N
Pozzolith 100XR
Qty. per Cu. Yd.
436
131
1134
1780
lbs.
lbs.
lbs.
lbs.
lbs.
35 gals.
As Required
As Required
As Required
Cement BOL
NCDOT Requirements & Concerns
• Each BOL must be accompanied by a
current cement mill test report
• Producers found non-complying with
NCDOT requirement (cement and
producer) will be removed from the
NCDOT approval list
• Alkali Silica Reactivity (ASR) is a very real
issue in North Carolina and the NCDOT is
addressing this critical area