2010 Concrete Sustainability Conference 1 © National Ready Mixed Conc

The Virtual Cement and 

Concrete Testing LaboratoryConcrete Concrete Testing Testing Laboratory

Laboratory

Application to Sustainability

Ed Garboczi, Jeff Bullard, and Nick Martys

Inorganic Materials Group Inorganic Materials Group

Materials and Construction Research Division
2010 Concrete Sustainability Conference 2 © National Ready Mixed Conc

NIST = National Institute of 

Standards and Technology Standards and Technology

• Mission (Department of Commerce, 1901)

– To promote innovation and competitiveness To promote innovation and competitiveness

through measurement, standards, and technology to enhance economic security and quality of life.

• Vision

– To be the global leader in measurements and 

enabling new technologies enabling new technologies.

• We’re mostly physicists, chemists, material

scientists and engineers scientists, and engineers
2010 Concrete Sustainability Conference 3 © National Ready Mixed Conc

Sustainable Infrastructure Materia

• S i Lif P di ti f Hi h P f P l d Service Life 

Predi

ction of High

Performance 

P

olymers an

d

Composites

• Reduced Flammability of Materials

• Sustainable Concrete Materials (SCM !)

– Material characterization– Rheology of concrete– Mitigation of early age Mitigation of early age-cracking in high volume fly ash concrete cracking in high volume fly ash concrete– Fundamental cement hydration modeling– Doubling service life of concrete

• Outputs of our core research program include Outputs of our core research program include

– New microstructure model for DOE durability of concrete for 

applications project

– Proposed generic technology for mitigation of early-age crac

– the Virtual Cement and Concrete Testing Laboratory (VCCTL

soft k ware pac

kage

– Measurement standards for rheology, X-ray diffraction, sulfa

attack, etc.
2010 Concrete Sustainability Conference 4 © National Ready Mixed Conc

Sustainability of concrete

• Sustainability has important societal and systems 

engineering aspects - focus on materials in this talk

• The industry needs tools to help quantify the effect 

new design decisions that attempt to make concret

more sustainable during the design, production, sustainable during the design, production,

placement, and maintenance processes, by consid

– energy– emissions– material sources

– performance properties– construction waste

– service life service life– maintenance schedule– ease of recycling
2010 Concrete Sustainability Conference 5 © National Ready Mixed Conc

Virtual Cement and Concrete 

Testin

g y Laborator

y

VCCTL
2010 Concrete Sustainability Conference 6 © National Ready Mixed Conc

Past and present members o

VCCTL consortium VCCTL consortium

• Past: PCA W R Grace VDZ ATILH : PCA, W.R. Grace, VDZ, ATILH, Holcim

Sika, BASF, Dyckerhoff, Cemex, NSSGA

• Present: FHWA, Mapei, RMC Foundation, 

Florida DOT

• We thank all of these for funding over 9 

years that has made this research and 

software development possible
2010 Concrete Sustainability Conference 7 © National Ready Mixed Conc

Fall 2009 Fall 2009

DepartmeCommercSilver Mefor VCCT

developm
2010 Concrete Sustainability Conference 8 © National Ready Mixed Conc

VCCTL Vision

• Compute

r-design concrete just like 

structural engineers computer structural engineers computer-design structures

– Performance prediction is a necessary foundation for effe

use of performance-based standards and specifications

– Since there is an increasingly wide class of materials goin

Since there is an increasingly wide class of materials goin

into concrete, can’t simply rely on empirical testing – too mvariables

– Accurate materials Accurate materials-science science-based characterization characterization and

prediction of performance is required so that 

– VCCTL will be an VCCTL will be an effective tool for optimizing the use o

existin existin

g gq and new materials for existin and new materials for existin

g re

quirements and 

uirements and 

requirements like sustainabilit

y
2010 Concrete Sustainability Conference 9 © National Ready Mixed Conc
2010 Concrete Sustainability Conference 10 © National Ready Mixed Conc

3 parts of Consortium Resear

• 3-D cement hydration modeling• 3-D concrete rheology simulation• Virtual testing lab (VCCTL) software
2010 Concrete Sustainability Conference 11 © National Ready Mixed Conc

3 parts of Consortium Resear

• 3-D cement hydration modeling• 3-D concrete rheology simulation• Virtual testing lab (VCCTL) software
2010 Concrete Sustainability Conference 12 © National Ready Mixed Conc

Com

p g utin

g Resources

• NASA and DOE (Argonne) supercomputers• NIST medium-size Linux cluster• Powerful desk-tops (e.g. dual quad-cores) t

the VCCTL virtual lab software 

– can also u

regular desktop or laptop for many applicati
2010 Concrete Sustainability Conference 13 © National Ready Mixed Conc

VCCTL analogy VCCTL analogy

• Virtual Testing Laboratory acts just lik

physical testing laboratory

• Databases replace material hoppers a

bins

• Material mixing models replace mixers

• Quantitative algorithms replace 

instrumented testing machines

• S ft i t f S

oftware in

ter

face repl lb t aces la

b car

t
2010 Concrete Sustainability Conference 14 © National Ready Mixed Conc

No ma

gic involved...

• No waving a wand and predicting the properties of 

anything...concrete is a complex material!

– Material characterization – details of mineralogy, particle shape, 

calorimetry

– Must know chemistry (thermodynamics and kinetics) of complex 

reactions

– Need to codify this knowledge into accurate models that give 3-D 

microstructures – otherwise property prediction is not accurate

• After all this hard work, the VCCTL tool becomes very powerfu• VCCTL has been designed using the computational materials 

science of concrete – based on fundamental chemistry and ph

– potential of application to almost any material problem in concret– sustainability– P2P
2010 Concrete Sustainability Conference 15 © National Ready Mixed Conc

Where VCCTL is ri

ght now

• Any portland cement, any aggregate

– Can add new material sources as needed with characterization

• Any time of hydration sealed or saturated isothermal or adiab

Any time of hydration, sealed or saturated, isothermal or adiab

• Can predict:

– elastic moduli– chloride diffusivity– heat of hydration heat of hydration– compressive strength– rapid chloride permeability test

• Some ability to handle fly ash and slag but not well Some ability to handle fly ash and slag, but not well-validated 

validated, 

missing a lot of thermodynamic and reaction details

• Nine years of development have given a tool that can effective

used ri

g, p p ht now, and which is 

poised for critical develo

pment fo

sustainabilit

y and other uses
2010 Concrete Sustainability Conference 16 © National Ready Mixed Conc
2010 Concrete Sustainability Conference 17 © National Ready Mixed Conc
2010 Concrete Sustainability Conference 18 © National Ready Mixed Conc
2010 Concrete Sustainability Conference 19 © National Ready Mixed Conc
2010 Concrete Sustainability Conference 20 © National Ready Mixed Conc
2010 Concrete Sustainability Conference 21 © National Ready Mixed Conc
2010 Concrete Sustainability Conference 22 © National Ready Mixed Conc
2010 Concrete Sustainability Conference 23 © National Ready Mixed Conc

Possible uses right now

• Evaluate properties of concrete made from various 

portland cement sources with differing mineralogy (

added silica fume) added silica fume)

– prediction of strength, elastic moduli, rapid chloride permea

test (= DC resistivity)

• Predict physical properties of concrete when coarse 

cement particles have been replaced with inert fille(e.g. limestone powder)

• Compute variation of concrete chloride diffusivity w

using various cements, aggregates, or mix designs
2010 Concrete Sustainability Conference 24 © National Ready Mixed Conc

Possible uses ri

ght now

• Effect of variability in materials dispensed at batch 

plt t f an

ts on concre

te per

formance

– explore how material variation affects performance variat

• Virtual testing of the effect of cement changes Virtual testing of the effect of cement changes, 

which come from changes in manufacturing conditions (e.g. lower T kiln, more or less grindingon concrete properties

– can associate any psd with any cement mineralogy

• Case studies showing differences between 

materials meeting prescription vs performance materials meeting prescription vs. performance

specifications
2010 Concrete Sustainability Conference 25 © National Ready Mixed Conc

Short-term improvements term improvements

• Prediction of coefficient of thermal 

expansion (CTE) to use in pavement 

d i es gn

• If user specifies costs of materials If user specifies costs of materials, 

software can output mixture costs (can include cost of chemical admixtures, b

not full chemistry)

– Other material accounting possible, too – 

embodied energy and CO embodied energy and CO

2 per volume of2 per volume of

concrete
2010 Concrete Sustainability Conference 26 © National Ready Mixed Conc

Short-term improvements term improvements

• Allow more than one cement (e.g. 1-10) to b

included in virtual mix, so blending two or mo

diff t t ld b l d di tl differen

t cemen

ts could

be explore

d directly 

before investing in more silos

• Make links to NIST pervious concrete tools 

more usable and accessible

• Workability “critical points” – predict maximu

packing fractions and how yield stress might packing fractions and how yield stress might 

affected
2010 Concrete Sustainability Conference 27 © National Ready Mixed Conc

Developmental needs related 

sustainability predictions sustainability predictions

• Better mineralogical characterization of fly ash and 

slag, leading to →→→→

• Development of more realistic chemistry and physic

these materials in hydration models and VCCTL these materials in hydration models and VCCTL

software 

– based on the thermodynamics of basic chemical reactions, 

which in many cases need to be measured (once and done

• Durability test prediction• Prediction of cracking and its effect on properties Prediction of cracking and its effect on properties
2010 Concrete Sustainability Conference 28 © National Ready Mixed Conc

VCCTL

• Performance 

p y rediction is a necessar

y

foundation for 

– Performance-based standards and specification–

O

p 

timization of concrete for criteria like sustaina

That is what VCCTL is being designed to do

• Collaboration with MIT Concrete Sustainabil

Hub is being planned to be able to complete 

multi

-scale picture of concrete from nanomet

scale picture of concrete from nanomet

to meters (see Prof. Ulm’s talk later in the conference

)
2010 Concrete Sustainability Conference 29 © National Ready Mixed Conc

Others

NIST

MIT
2010 Concrete Sustainability Conference 30 © National Ready Mixed Conc

Prospectus

• In 2010, 2011, and 2012, we will be working on

– making the VCCTL software more usable and powerful– how to 

get this software into the hands of more users via 

workshops, cooperative a

greements, commercialization, us

groups, etc.

• Your ideas are most welcome! Your ideas are most welcome!

– Edward.Garboczi@nist.gov

Especially concerning sustainability!

Th k ! an

k you!