Presentation on theme: "Portland Cement Joe Diedrich Technical Services Manager."— Presentation transcript:
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
Process of clinker production
Clinker is ground with gypsum into portland cement & shipped
Cement component terminology In 1897, Tornebohm, a Swedish scientist clearly described the optical features of the principal clinker phases in thin sections and powder mounts and coined the terms “Alite”, “Belite”, and “Celite”.
Alite - Crystals generally termed C 3 S
Alite (C 3 S) Scanning electron microscope photo
Belite – C 2 S
C3A - Tricalcium Aluminate Part of “matrix” - fills interstices between crystals of C 4 AF and C 2 S.
Ferrite – (C 4 AF)
Cement recipe Limestone – CaO Sand – SiO 2 Clay and/or Shale – Al 2 O 3 Iron Ore or Mill Scale – Fe 2 O 3 Gypsum ASTM C 150
Hydration of the cement compounds CompoundReaction Rate Strength Contribution Heat Contribution C3SModerateHigh EarlyHigh C2SSlowHigh LaterLow C3AFastLowVery High C4AFModerateLowModerate
Strength contribution by the compounds
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) Concrete Strength Happens Calcium Silicate Hydrate
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 Inormal, general-purpose cement Type IAnormal, air-entraining Type II (MS)moderate sulfate resistance Type II MHmoderate sulfate resistance and moderate heat of hydration Type IIIhigh early strength (Typically Type I ground 50% finer) Type IVlow heat of hydration (very uncommon) Type Vhigh sulfate resistance
What is the difference between Type I and Type II? Type I has no C 3 A limit, however, a Type II is limited to a maximum of 8% C 3 A There is no such thing as a Type I/II cement. This is slang terminology for a product that meets criteria for both Types.
What’s difference between Type I and Type II? Compared to a Type I, the Type II has slightly lower minimum compressive strength requirements.
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.
What’s the difference between a Type II and a Type V? Type V has the same strength requirements as Type II at 1 day and 3 days. Type V has a lower minimum required 7 day strength. Type V has a minimum required 28 day strength, Type II does not.
What’s the difference between a Type II and a Type V? Type V has an optional sulfate resistance % expansion. Type V does not have any optional strength requirements.
Performance of Concretes with Different Cements in Sulfate Soil
Performance of Concretes with Different W/C- Ratios 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 C 3 S and C 3 A 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.
What’s the difference between a Type II and a Type II MH? Type II MH has an optional heat of hydration limit that can apply when specifically requested. If requested, the sum of C 3 S+4.75(C 3 A) requirement does not apply. The lower 28 day strength minimum limits apply when the optional heat of hydration limitation is requested.
Type III High Early Strength Cements
What is different about a Type III? Type III cements have a higher SO 3 maximum limit because of their fineness. Type III cements also have a higher maximum C 3 A limit.
What is different about a Type III? Type III cements can have optional C3A limitations applied for moderate or high sulfate resistance. All of the C150 optional limitations for all types of cement apply only when specifically requested.
What is different about a Type III? Type III cements do not have a standard physical requirement for fineness. Type III cements are the only Type with a 1 day minimum strength requirement and they have a higher 3 day requirement.
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
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 2009 Cement Specs Update
Understanding a Cement Mill Test Report
Plant and Production Info Chemical Data Physical Data General Info 4 main parts of Cement mill test report
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
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