product availability from a to z

Product AvailabilityFrom A to Z….

Megan Dangel, P.E.Technical Services Engineer – Central Plains Cement

Company

NCPA – Concrete Paving WorkshopJanuary 20, 2016

• Current product availability• Possible alternatives• History of slag cement• How it is reclaimed and collected• How they work • Characteristics and Benefits• What this means to Nebraska

Learning Objectives

Product Availability

• Cement• Fly Ash ???The Perfect Storm

Image source: American Coal Ash Association

Product Availability

Product AvailabilityFly Ash – The Perfect Storm?

As of January 2014, 40.5 GW of coal-fired capacity publically announced retirement effective through 2020


Image source: ENERGY INFORMATION ADMINISTRATION, FORM EIA-860, “ANNUAL ELECTRIC GENERATOR REPORT.”


• 204 generating units in over 25 states

• >11% reduction in total coal fired generating capacity

• >40% of capacity reduction in Midwest, Mid Atlantic, and Southeast states

• >7 Million ton reduction in fly ash production

204>11%

>40%

>7 Source: ENERGY INFORMATION ADMINISTRATION, FORM

EIA-860, “ANNUAL ELECTRIC GENERATOR REPORT.”


Possible Alternatives

• Class N Pozzolans• Calcined clay & shale• Metakaolin• Diatomaceous earth• Volcanic ash

• Lithium Nitrate • Slag Cement

What is slag cementMore important…..what do we call it?

• Finely ground material consisting of primarily calcium and aluminum silicates• Uses as a partial replacement for portland

cement• Names• Ground Granulated Blast Furnace Slag• GGBFS• Slag• Slag Cement• Trademark Name

Best General Term

Roman cements

and concrete

Aspdinpatentsportlandcement

Slag cement produced as a separat

e materia

l

Widespread use in Eastern

U.S.

Loriotmakesslag- lime

mortar

First slag-portla

nd blend

ed cemen

ts

...300-500 BC 1824 1950’s 2000’s1774 1890’s 1982

Rapid expansion throughout U.S.

History of slag cement

Reclaimed and CollectedThe Blast Furnace

Reclaimed and Collected

16


• Portland Cement• 370 m2/kg

• Fly Ash• 650 m2/kg

• Slag Cement• 550 m2/kg

• Cigarette Smoke• 3500 m2/kg

• Silica Fume• 4000 m2/kg

Characteristics and Benefits Particle Sizes of Slag Cement

Void(including Ca[OH]2)SCM(ie. Slag)

Additional glue(from SCM hydration, including

converted Ca[OH]2)

Portland Cement

C-S-H(glue formed when cement

hydrates)

SAND

How Slag Cement Works

Plastic Properties• Better slump retention

• Enhanced workability

• Easier consolidation

• Improved pumpability

• Superior finishability

• Consistent air content

Properties and Characteristics

Hardened Properties• Improved compressive & flexural strengths

• Reduced permeability

• Improved corrosion resistance

• Increased resistance to sulfate attack & ASR

• Reduced heat generation

• ASR is a constant concern

• Several published recommended guidelines for mitigating ASR• AASHTO PP 65

• Easily downloaded program to navigate specifications

How it Relates to Nebraska

How it relates to NebraskaAASHTO PP 65

• Current product availability• Possible alternatives• History of slag cement• How it is reclaimed and collected• How they work • Characteristics and Benefits• What this means to Nebraska

Learning Objectives

Megan Dangel, P.E.Technical Services Engineer – Central Plains Cement Company

[email protected]

product availability from a to z

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