Workshop on Nanotechnology for Cement and Concrete September 5, 2007
Report of the Workshop on Nanotechnology for Cement and Concrete
September 5, 2007
Peter Taylor Krishna Rajan Bjorn Birgisson Tom Cackler
Sponsored by The National Concrete Pavement Technology Center and the National Science Foundation, in Cooperation with the Nanoscale Science, Engineering, and Technology (NSET) Subcommittee of the U.S. National Science and Technology Council, through the National Nanotechnology Coordination Office ii I Workshop on Nanotechnology for Cement and Concrete Thanks gotothepresenters forpermissionto reproduce theirpresentations. Foundation. are thoseoftheauthor(s)anddonotnecessarilyreflect ofthe theviews National Science Any opinions,findings,andconclusionsor recommendations expressed inthismaterial fordevelopment ofthisreportsupport were madepossibleby NSFGrant CMMI0749499. Travel anduniversity attendeesand oftransportation formoststatedepartment support through theNational Nanotechnology Coordination Office. Technology Subcommittee (NSET) oftheU.S.National Scienceand Technology Council, National ScienceFoundation, inCooperationwiththeNanoscale Science,Engineering, and The workshop wassponsored by The National Concrete Pavement TechnologyCenterandthe Acknowledgments applications ofnanotechnologytocementandconcrete. andpublicagenciesspecificallyfor of priorityinterest andcollaborationbetween industry on September 5,2007.Theobjective ofthemeetingwastoprovide nationaldirection onareas This documentsummarizes thediscussionsandfindingsofa workshop heldinArlington, VA, Preface
iii I Workshop on Nanotechnology for Cement and Concrete
Breakout Sessions
Appendices Outcomes Preface Acknowledgments Workshop onNanotechnology forCementandConcrete Table ofContents Plans forthefuture Roundtable Discussion Table ofContents Introduction Presentations Summary Durability 2 Durability 1 Roadmap forResearch High Performance 2 The Nano-Engineering ofUHPC& Structures High Performance 1 New Functionalities fortheBuilding Industry Sustainability 2 Nanoscience ofHighway Materials Construction Sustainability 1 The Future ofConcrete Collaborative effort Nanocem -European Efforts Appendix B:Attendance A Vision Needs Nano House Background Appendix A:Agenda Common Themesand Priorities Background Snapshot oftheNational Nanotechnology Initiative The Challenge Constraints
ii 58 58 57 45 56 41 55 37 54 29 53 23 63 53 15 69 62 52 67 61 51 67 65 61 51 51 iii 9 2 7 1 1 5 v i
I Workshop on Nanotechnology for Cement and Concrete
ER365, 2007 2 in theUK”,Energy, Volume 27,Issue 1,January 2002,Pages 77-92. 1 industry.facing theconstruction ofconcreteenhance thedesirableproperties whilehelpingtoaddress someofthechallenges strength. It isusedin arelatively wayinthefield. crude Nanotechnology hasthepotentialto hours, thatcanbeformedintoanygeometricalshape, andthathardens anddevelops high mixing thismaterialwithwater, material thatisworkable you formany getaconstruction energy-efficient of abundantrawmaterialsavailable byprocess. almosteverywhere avery By generally low-paid workers with amodicumofqualitycontrol. Imagine amaterialmadeout Concrete materialis unique becauseitisacommodity, asaconstruction fabricatedonsiteby us to fit into. Even so, section thicknesses in structures have not changed significantly over time. ofstructures. same isnottrue This is partially so because buildings still have to be big enough for are several orders ofmagnitudesmallerandcheaper thantheywere decadesago, butthe afew A challengefacingmaterialsengineersworking inconcrete isthatmostothermodernsystems assumption thatforeachtonofcement,0.9tonsCO worldwide, meaningthatupto2.08millionmetrictonsofCO Association (PCA)reports that2.310millionmetrictonsofcementwere produced in2005 embodied energypersquare footoffloorarea forofficebuildingsthansteel other materials.Published dataare varied, buttypicallyconcrete isreported tohave lower environment. Concrete produces lower emissionsandhaslower embodiedenergythan has tobepaidmakethematerialmore sustainableandimposealower burden onthe embodied energy, theshearvolumes ofconcrete produced worldwidemeanthatattention Another issueisthatwhiletheproduction ofconcrete isefficientintermsofemissionsand impact ontheeconomy. at present. Animprovement inreliability ofconcrete systemswillhave amultibilliondollar generally acceptedthatadequatetestmethodsandtoolstomeasure are performance lacking away from prescriptive specifications; specificationstoperformance-based however, itisalso devastating, leadingtosignificant overdesign ofmanyfacilities.There isa movement to move becausetheconsequences offailure isgenerallyconservative are of litigation.Theindustry with thecurrently acceptedrisksinherent alongwiththeassociatedhighlevels inconstruction, benefits.Alotofattentionisfocusedondealing significant economicsavingsandperformance worldwide,even asmallreduction inthenumberofproblemsindustry wouldamountto standard from thebeginning.Consideringthatconcrete isa700billiondollar construction It isestimatedthatupto10%ofconcrete placedinagiven year failsprematurely orisbelow One significantneedoftheconcrete materialistosignificantlyincrease construction reliability. materialbecomeincreasinglyconstruction apparent. demandsareperformance placedontheproduct, thelimitationsofmodernconcrete asa little sinceitsfirstusageincurrent formonehundred years ago. Asincreasingly higher difficult toimaginelifewithoutit. However, concrete asamaterialhaschanged relatively Its significancetothebasicinfrastructure ofmoderncivilizationisimmeasurable,andit Concrete asamaterialisthemostcommonlyused(otherthanwater)onplanet. The Challenge Introduction North AmericanCement Industry, Annual Yearbook, 2006,Skokie, IL,Portland CementAssociation, Yohanis, Y.G., andNorton, B.,“Life-cycle operationaland embodiedenergyforagenericsingle-storey officebuilding 2 are released). 2 were released (basedon the 1 . Portland Cement
2
I Workshop on Nanotechnology for Cement and Concrete I Workshop on Nanotechnology for Cement and Concrete Introduction 4 3 (crosses), and adsorbedwater molecules (circles). Figure layers showing C-S-H ofC-S-H, 2.Amodelofthestructure (lines),interlayer water molecules ______Figure range 1.Dimensional ofsolidsandpores inahydrated cement paste ______pores filledwithinterlayer andadsorbedwater(Figure 2) of calciumsilicatehydrate ismuchlikeaclay, withthinlayers ofsolidsseparatedby gel Fundamentally, hydrated cementpaste(HCP)isananomaterial(Figure 1) thatisbasedondurabilityandcrackresistance,performance ratherthansimplystrength. seen tenyears ago. Additionally, aspreviously noted,engineersare moving toward requiring and risksofproblems, asillustratedbyemphasis on incompatibilitythatwasnot anew-found cementitious materials. With increasing numberofingredients comeincreasing complexity or more ingredients withtheadditionofmultiplechemicaladmixtures andsupplementary from mixes withfourbasicingredients (cement,water, sand,andstone)tomixes withnine aggressively pursued.However, concrete systemsare growing increasingly complex,changing parameter ofconcern,afundamentalunderstandinghow thesystemworks hasnotbeen to beeconomicallyfunctional.It hasbeen abuserfriendly, andbecausestrength wastheonly predictable thanmetals.Also,inmanyways,current knowledge hasbeengoodenoughforit materials engineeringcircles, possiblybecauseitisnotacarbohydrate andbecauseitisless The studyofcementitioussystemshasnotgainedmuchattentioninmaterialsscienceand Background Taylor, H.F.W., “CementChemistry,” 2nd Edition, London,Thomas Telford, 1997. Mehta, P.K., “Concrete Structure, Properties and Materials,” Engelwood Cliffs, NJ, Prentice-Hall, 1986. 4 . Thishassignificantimpactonthe 3 . Thestructure 6 the nanoporosity ofcement paste,” CementandConcrete Research, Vol. 37.,2007, pp. 329–336. 5 discussions. Thematerial covered inallofthesesessionsfollows. The meetingincludedten presentations, a roundtable discussion,and sixbreakout group understanding cementhydration at a molecularlevel. stated goalofconductingfundamentalresearch oncementitiousmaterialswithanemphasis representative ofNanocem, aEuropean withthe initiative thatisfundedprimarily by industry concrete structures andregulators ofsuch,andacademia.One of thepresentations includeda industry,construction product manufacturers, government agencies,includingowners of is feasiblebasedoncurrent knowledge. In attendancewere representatives oftheconcrete successes already achieved andguidancefrom thosecurrently working intechnologyonwhat is conceivably possibleinthenearterm.Input tothediscussionsalsoincludedexamplesof regardingindustry needsthatshouldbeaddressed now, basedonwhatisrequired, andwhat The aimofthe2007workshop wastobuildonthe2006workshop and toseekinputfrom 2006 workshop are asfollows: structures, includinghousing,bridges,tunnels,andpavements. Theneedsexpressed duringthe defined outcomesthatwillgreatly enhanceconcrete technologyandtheusesofconcrete in Research forConcrete-Based Materials. The roadmap isdestinationorientedwithclearly with over 30presentations A workshop attheUniversity ofFlorida inAugust 2006wasattendedby over 70participants, to meetthoseneeds,whichisthesameapproach beingadopted inthismeeting. withtheirneedsandthenusingnanotechnology isadoptinganapproach ofstarting industry ingredient inconcretelignin, whichisaprimary admixtures, whilethechemicalproducts for forest products andchemicalproducts. Forestry islookingatwaystomanipulateanduse technology toenhancetheirproducts. Notable overlaps withourwork are roadmaps developed lookingatusingnanoscienceand isnottheonlyindustry The concrete industry construction including shrinkageandknowing/controlling thedegree ofhydration. modify thecementitioussystemtoaddress theissuesconfronting sites, working construction cementitious system.Based knowledge, onthisnew itistherefore feasibletoconsiderhow to to improve thetoolsandskillsthatwe needtotakeafundamentallookat thehydrated As computingcapabilitiesgrow andnanotechniquesare developed, we now are starting shrinkage andconsequentcrackingifaccommodationsinelementsizes are notmade ofconcreteperformance becauseHCPissensitive tomoisture movement, whichcanleadto http://www.ce.ufl.edu/nanoworkshop/program.html, 2007 Jennings, H.M.,Thomas,J.J., Gevrenov. J.S.,Constantinides,G.,and Ulm, F-J., “A multi-technique investigation of • • • • • characterization andmodelingofconcrete atthenano-,micro-, meso-,andmacroscales. Development offundamental multiscalemodel(s)forconcrete through advanced processing ofcementandpaste. Development ofnovel concrete materialsthrough nanotechnology-based innovative based self-sensingandself-powered materialsandcyberinfrastructure technologies. Development ofintelligent concrete materialsthrough theintegrationofnanotechnology- production, andenhancingsafetywithnano-engineeringofconcrete materials. concrete fordifferent adverse environments, reducing energyconsumptionduringcement Development ofsustainable andsafeconcrete materials andstructures through engineering mechanical, durability, andshrinkageproperties. Development cementandconcrete ofhigh-performance materialsasmeasured by their 6 . Themeetingfocusedonthedevelopment ofa Roadmap for 5 .
I Workshop on Nanotechnology for Cement and Concrete Introduction
Presentations 8. 7. 6. 5. 4. 3. 2. 1. Roadmap forResearch—Dr. BjornBirgisson The Nano-Engineering ofUHPC& Structures—Vic Perry New Functionalities fortheBuilding Industry—Dr. Laurent Bonafous Nanoscience ofHighway Materials—Dr. Construction Richard Livingston The Future ofConcrete—Dr. Felek Jachimowicz Nanocem—European Efforts—Vagn Johansen Nano House—Dr. Mike Roco Snapshot oftheNational Nanotechnology Initiative—Dr. Clayton Teague
I Workshop on Nanotechnology for Cement and Concrete
Snapshot oftheNationalSnapshot Nanotechnology Initiative Dr. Clayton Teague
I Workshop on Nanotechnology for Cement and Concrete Presentation 1 Snapshot of the National Nanotechnology Initiative Dr. Clayton Teague Presentation 1 Snapshot of the National Nanotechnology Initiative I Workshop on Nanotechnology for Cement and Concrete Dr. Clayton Teague Snapshot oftheNationalSnapshot Nanotechnology Initiative Dr. Clayton Teague Nano House Dr. Mike Roco
I Workshop on Nanotechnology for Cement and Concrete Presentation 2 Nano House Dr. Mike Roco Presentation 2 Nano House 10 I Workshop on Nanotechnology for Cement and Concrete Dr. Mike Roco Nano House Dr. Mike Roco Nano House Dr. Mike Roco
11 I Workshop on Nanotechnology for Cement and Concrete Presentation 2 Nano House Dr. Mike Roco Presentation 2 Nano House 12 I Workshop on Nanotechnology for Cement and Concrete Dr. Mike Roco Nano House Dr. Mike Roco Nano House Dr. Mike Roco
13 I Workshop on Nanotechnology for Cement and Concrete Presentation 2 Nano House Dr. Mike Roco
Nanocem -European Efforts Vagn Johansen
15 I Workshop on Nanotechnology for Cement and Concrete Presentation 3 Nanocem - European Efforts Vagn Johansen Presentation 3 Nanocem - European Efforts 16 I Workshop on Nanotechnology for Cement and Concrete Vagn Johansen Nanocem -European Efforts Vagn Johansen Nanocem -European Efforts Vagn Johansen
17 I Workshop on Nanotechnology for Cement and Concrete Presentation 3 Nanocem - European Efforts Vagn Johansen Presentation 3 Nanocem - European Efforts 18 I Workshop on Nanotechnology for Cement and Concrete Vagn Johansen Nanocem -European Efforts Vagn Johansen Nanocem -European Efforts Vagn Johansen
19 I Workshop on Nanotechnology for Cement and Concrete Presentation 3 Nanocem - European Efforts Vagn Johansen Presentation 3 Nanocem - European Efforts 20 I Workshop on Nanotechnology for Cement and Concrete Vagn Johansen Nanocem -European Efforts Vagn Johansen Nanocem -European Efforts Vagn Johansen
21 I Workshop on Nanotechnology for Cement and Concrete Presentation 3 Nanocem - European Efforts Vagn Johansen Presentation 3 Nanocem - European Efforts 22 I Workshop on Nanotechnology for Cement and Concrete Vagn Johansen Nanocem -European Efforts Vagn Johansen The Future ofConcrete Dr. Felek Jachimowicz
23 I Workshop on Nanotechnology for Cement and Concrete Presentation 4 The Future of Concrete Dr. Felek Jachimowicz Presentation 4 The Future of Concrete 24 I Workshop on Nanotechnology for Cement and Concrete Dr. Felek Jachimowicz The Future ofConcrete Dr. Felek Jachimowicz The Future ofConcrete Dr. Felek Jachimowicz
25 I Workshop on Nanotechnology for Cement and Concrete Presentation 4 The Future of Concrete Dr. Felek Jachimowicz Presentation 4 The Future of Concrete 26 I Workshop on Nanotechnology for Cement and Concrete Dr. Felek Jachimowicz The Future ofConcrete Dr. Felek Jachimowicz The Future ofConcrete Dr. Felek Jachimowicz
27 I Workshop on Nanotechnology for Cement and Concrete Presentation 4 The Future of Concrete Dr. Felek Jachimowicz Presentation 4 The Future of Concrete 28 I Workshop on Nanotechnology for Cement and Concrete Dr. Felek Jachimowicz The Future ofConcrete Dr. Felek Jachimowicz Nanoscience ofHighway Materials Construction Dr. Richard Livingston
29 I Workshop on Nanotechnology for Cement and Concrete Presentation 5 Nanoscience of Highway Construction Materials Dr. Richard Livingston Presentation 5 Nanoscience of Highway Construction Materials 30 I Workshop on Nanotechnology for Cement and Concrete Dr. Richard Livingston Nanoscience ofHighway Materials Construction Dr. Richard Livingston Nanoscience ofHighway Materials Construction Dr. Richard Livingston
31 I Workshop on Nanotechnology for Cement and Concrete Presentation 5 Nanoscience of Highway Construction Materials Dr. Richard Livingston Presentation 5 Nanoscience of Highway Construction Materials 32 I Workshop on Nanotechnology for Cement and Concrete Dr. Richard Livingston Nanoscience ofHighway Materials Construction Dr. Richard Livingston Nanoscience ofHighway Materials Construction Dr. Richard Livingston
33 I Workshop on Nanotechnology for Cement and Concrete Presentation 5 Nanoscience of Highway Construction Materials Dr. Richard Livingston Presentation 5 Nanoscience of Highway Construction Materials 34 I Workshop on Nanotechnology for Cement and Concrete Dr. Richard Livingston Nanoscience ofHighway Materials Construction Dr. Richard Livingston Nanoscience ofHighway Materials Construction Dr. Richard Livingston
35 I Workshop on Nanotechnology for Cement and Concrete Presentation 5 Nanoscience of Highway Construction Materials Dr. Richard Livingston Presentation 5 Nanoscience of Highway Construction Materials 36 I Workshop on Nanotechnology for Cement and Concrete Dr. Richard Livingston Nanoscience ofHighway Materials Construction Dr. Richard Livingston 6. New for Functionalities theBuildingIndustry Dr. Laurent Bonafous
37 I Workshop on Nanotechnology for Cement and Concrete Presentation 6 New Functionalities for the Building Industry Dr. Laurent Bonafous Presentation 6 New Functionalities for the Building Industry 38 I Workshop on Nanotechnology for Cement and Concrete Dr. Laurent Bonafous 6. New for Functionalities theBuildingIndustry Dr. Laurent Bonafous 6. New for Functionalities theBuildingIndustry Dr. Laurent Bonafous
39 I Workshop on Nanotechnology for Cement and Concrete Presentation 6 New Functionalities for the Building Industry Dr. Laurent Bonafous Presentation 6 New Functionalities for the Building Industry 40 I Workshop on Nanotechnology for Cement and Concrete Dr. Laurent Bonafous 6. New for Functionalities theBuildingIndustry Dr. Laurent Bonafous 7. ofUHPC&Structures The Nano-Engineering Vic Perry
41 I Workshop on Nanotechnology for Cement and Concrete Presentation 7 The Nano-Engineering of UHPC & Structures Vic Perry Presentation 7 The Nano-Engineering of UHPC & Structures 42 I Workshop on Nanotechnology for Cement and Concrete Vic Perry 7. ofUHPC&Structures The Nano-Engineering 7. ofUHPC&Structures The Nano-Engineering Vic Perry Vic Perry 7. ofUHPC&Structures The Nano-Engineering Vic Perry
43 I Workshop on Nanotechnology for Cement and Concrete Presentation 7 The Nano-Engineering of UHPC & Structures Vic Perry Presentation 7 The Nano-Engineering of UHPC & Structures 44 I Workshop on Nanotechnology for Cement and Concrete Vic Perry 7. ofUHPC&Structures The Nano-Engineering 7. ofUHPC&Structures The Nano-Engineering Vic Perry Vic Perry 8. Roadmapfor Research Dr. BjornBirgisson 8. Roadmap for8. Roadmap Research Dr. Birgisson Bjorn
45 I Workshop on Nanotechnology for Cement and Concrete Presentation 8 Roadmap for Research Dr. Bjorn Birgisson Presentation 8 Roadmap for Research 46 I Workshop on Nanotechnology for Cement and Concrete Dr. Bjorn Birgisson 8. Roadmapfor Research 7. ofUHPC&Structures The Nano-Engineering Dr. BjornBirgisson Vic Perry 8. Roadmapfor Research Dr. BjornBirgisson 8. Roadmap for8. Roadmap Research Dr. Birgisson Bjorn
47 I Workshop on Nanotechnology for Cement and Concrete Presentation 8 Roadmap for Research Dr. Bjorn Birgisson Presentation 8 Roadmap for Research 48 I Workshop on Nanotechnology for Cement and Concrete Dr. Bjorn Birgisson 8. Roadmapfor Research 7. ofUHPC&Structures The Nano-Engineering Dr. BjornBirgisson Vic Perry 8. Roadmapfor Research Dr. BjornBirgisson 8. Roadmap for8. Roadmap Research Dr. Birgisson Bjorn
49 I Workshop on Nanotechnology for Cement and Concrete Presentation 8 Roadmap for Research Dr. Bjorn Birgisson
are analogous tohydrated cementpasteandmayprovide work: ausefulbackground for further the caseswhere concrete materialsare used.Thefollowing, betterunderstood,materialstypes Committee 236.It wasnotedthatthestateofknowledge haseffectively beengoodenoughfor bibliography ofreported work inthisfieldisbeingdeveloped by AmericanConcrete Institute the nano-andmicrostructure ofcementitioussystemsincomparisontoother materials.A In comparisontoothermaterials,relatively littlework hasbeenconductedonunderstanding Background industry: constrained by thefollowing before theywillfindbroad applicationinthe construction It isperceived atpresent thatanywork conducted orinnovations developed willlikelybe Constraints summarized below. divided intothree categories:constraints,background, andneeds.Eachofthesecategoriesis needs thatcouldbemetusingnanotechnologyandnanoscience.Thediscussionpointscan (includingsomeprioritization),andtoidentifythose industry the needsofconstruction The aimwastoallow allthosepresent toexpress theopportunity theiropinion/positionon A roundtable discussionwasheldover aone-hourperiod,facilitatedby Dr. KrishnaRajan. Roundtable Discussion • • • • • • • short term. short Emphasis should beplacedonseekingsolutionsthatare practicalandachievable inthe environment shouldtheybereleased orleached from theconcrete. nanomodified materialswillhave tobeexaminedfortheireffectsonhealthandthe tendstobelaborintensive andisgenerallyoutdoors, meaningthat Construction constraint. technical acceptability. andpolicydirectives Educational efforts are required toaddress this aggregates)constrained intousinglocallyavailable materials(particularly regardless oftheir Costs ofmoving bulkrawmaterialsare high,meaningthat,ingeneral,usersare Policy changesare neededtohelpremedy thisconstraint. concrete, therefore removing anymotivation tomakecementhydration more efficient. or materials.For example,manyspecificationswillnotallow lower cementcontentsin Contracts tendtobeinflexible,oftenlimitingtheacceptabilityofinnovative approaches has toaccompanychangesintechnology. well; therefore, themixture hastobeinsensitive tomistakesandvariability, andeducation People involved inmakingandplacingconcrete generallydonotunderstandthematerial sustainability pointofview. to thefulllifecycle of aconcrete mixture, includingdisposalorrecycling costsfrom a Despite theemphasisonfirstcostfrom abudgetstandpoint,attentionmustbepaid means thatthesystemisextremely withrespect costsensitive, particularly tofirst cost. Concrete isacommoditymaterial,typicallysoldandplacedunderlow-bid contracts.This
51 I Workshop on Nanotechnology for Cement and Concrete 52 I Workshop on Nanotechnology for Cement and Concrete Roundtable Discussion construction industry toflourish,thefollowing needsshouldbeaddressed: industry construction for amixture andthenengineeringthematerialstoprovide For thoseproperties. theconcrete It wassuggestedthatconsiderationshould begiven todeveloping needed thelistofproperties Needs • • • • • • • • • • • • brittle withlow toughnessandtensilestrength. In contrast,cementpasteisalsocompared toceramicsystemsbecauseitisinherently that issensitive tomoisture movement withinthegelpores. They are alsoanalogoustoclaysbecausecalcium-silicate-hydrate hasalayered structure in thattheyare complexandamorphousmultiphasemixtures. Hydrated cementpastesmaybecompared form topolymericmaterialsintheirstructural cementitious systemsatananoscaleandtofacilitatemodifying concrete systems. Advances computingshouldbetakenadvantage oftomodel inhighperformance (and how itchangeswithtime)anddurability. Immediate andpracticalrequirements are neededforimproved control over workability sustainable. Methods tomakeuseofmarginalaggregates are required ifconcrete istobe construction order toreduce theriskofcracking. Materials shouldbe soughtthatreduce orcontrol thetimingofshrinkageinconcrete in occurring withinit. failures are duetounexpectedmaterialsbeingincludedinthemixorreactions Means are neededtomakeconcrete anditsingredients more uniform andstable.Many consideration. important as acriterion,butthismaynotbeappropriate whendurabilityislikelytobecomeamore may bemeasured usinganumberofparameters.Engineers historicallydependonstrength material (a15%increase wasdiscussed).It ofcement mayalsobenotedthatperformance view, eitherby mixingwithothermaterials,and/orby increasing ofthe theperformance Usage ofclinkerhastobecomesignificantlymore efficient fromanenvironmental pointof required iftheyare tobefundamentallyandscientificallymodified. A betterunderstandingofcementitiousmaterialsandtheirhydration mechanismsis ofamixtureControl systemstomodifytheperformance ontheflyare desirable. requirements andawayfrom recipe bookapproaches. tests andlimitsare available, thenspecificationscanmove toward callingoutperformance Test methodsandtoolstoassessthequalitystateofamixture are essential.If suitable Sustainability 1 Sustainability ofthefindings ofeach The followinggroup. isa summary asked toaddress theirtopicaround thefollowing questions: followed by anhourofreporting anddiscussion.Eachgroup ofapproximately ninepeoplewas manufacturers, associations,andacademia.Thegroups metforapproximately onehour, to eachgroup toensure thatgroups includedrepresentatives from government, product similaritiesanddifferences betweenand toobserve theirfindings. Individuals were pre-assigned and “Durability.” Eachtopicwasdiscussedby twogroups inorder tokeepthegroups small Six breakout sessionswere held,covering three topics:“Sustainability,” “High Performance,” Breakout Sessions 7 Solutions Need General Invited PCA, http://www.cement.org/concretethinking/FAQ.asp • • • • What isthelow-hanging fruit? Who candoitandhow? How cannanotechnologyhelpusgetthere? What dowe need?
– There isacriticalneedto reduce CO – Increase thelifeofhighwaysandstructures whichwillleadtolower cement – Allinterested from manufacturers, parties, consumers,andowners to – Collaborationwithotherindustries/government bodies willassistinfinding – Specifications shouldmove awayfrom prescriptive toperformance-based – Innovations developments andnew mustbecostneutral.Theimprovements, – toquantifythetargets assistthe When developing goals,itisimportant Steve Kosmatka (Facilitator), James Alleman,Jim Armaghani,Fred Hejl, Al Innis, Vagn Johansen, Daniel Rardon, Clayton Teague, Jerry Voigt
the United States.) (Cement manufacture reportedly generatesabout1.5%ofman-madeCO consumption andthereby lessCO detail andinfundingdeveloping thesolutionstothem. regulators andresearchers, willhave tobeinvolved in definingtheneedsin solutions tothefollowing issues. approaches toallow innovations tobeimplemented. for instancethinnerpavements, shouldbalancehigherpricesformaterials. researchers andtoinformthefundingagencies. more cementwithlessCO therefore, iftheratiooftensile strength tocompressive strength couldbe and fatigue. Tensile failure factorindeterioration; ofthepaste isanimportant harsh environments, exposure tochemicalsandingress ofaggressive fluids, forlifetimewereimportant listedasmaterialsdegradationfrom exposure to materials. Thiswouldaddress allissues related tosustainability. Factors 7 Demand on thecementmanufacturers isto produce 2 from the same rawmaterials. 2 emissionandlower consumptionofraw 2 production from cementplants.
2 in
53 I Workshop on Nanotechnology for Cement and Concrete 54 I Workshop on Nanotechnology for Cement and Concrete Breakout Sessions Sustainability 2 Sustainability
Needs Invited Low Fruit Solutions Need
– SequesterCO orharvest – Reduce clinkercontentsinconcrete whilemaintainingdesired properties,
– Have ananocatalysttosplitCO – Methods to reduce clinkercontentinconcrete becauseitistheproduction of With tobeable increasing demandforsustainabledevelopment, itisnecessary – Ways toreduce CO Richard Livingston(Facilitator), John Brighton, Tom Cackler, Rita Chow, Peter research goalstogovernment.– Communicationofindustry – Development ofmethodstomonitorandcontrol cementitiousmaterials – Quantification ofneededtensilestrengths. – Investigate theconceptofnanomodificationpoor-qualityaggregates. – Use nanoclaystoimprove concrete properties. – Considertwo-layer withpoorer pavement construction gradematerialsinthe – Improve thequalityofpaste, allowing lower gradeaggregates tobe
Deem, Kevin McMullen, Uwe Schutz,Leif Wathne marginal orunacceptable. to increase aggregates) theuseofmaterials(particularly currently considered – Use CO – Use nanotechnologytodevelop concrete withlessrolling resistance, surfaces in monitoringit. in smallquantitiestoenhanceconcrete properties. thereby usingthinnerconcrete andlessmaterial.Nanomaterials couldbeused 2007 issue, The Economist has an article aboutCO 2007 issue,The Economist hasanarticle across manyindustries,includingpower industry. (In theSeptember 8–14, nanotechnology. clinker thatproduces CO hydration. lower layer andhigh-gradematerialsinthewearing surface. hydration ofthecement. acceptable. Akeytothiswill,again,betheabilityimprove thedegree of CO monitor thedegree ofcementhydration. strength. Thetechnologycouldalsobeusedtocontrol, improve, and/or be usedtoimprove durability(resistance toenvironment) andtensile increased, thesituationwouldbegreatly improved. Nanotechnology could which willleadtolower fuelconsumptionandlower emissions. plant exhaustgasby growing algae.) 2 . Nanotechnology outtheprocess and couldbeusedtoassistincarrying 2 tocarbonateconcrete andtoconsume tomodifyearlyproperties 2 footprintfrom theproduction ofcement. 2 from cementplantsintoausefulproduct using 2 andconsumes energy. 2 intoO 2 andC.Thisshouldbeaproject 2 capture from apower
High Performance 1
Needs General Invited Solutions
– Ensure thatconcrete can berecycled attheendofitsfunctionallife. Laurent Bonafous,David Carson,Brian Green, RandellRiley, Mike Roco, – Control concrete characteristicsforskidresistance surface andnoise – Control offresh rheologicalproperties concrete. – Use marginalaggregates orreclaimed concrete aggregates. – Produce amore uniformandcontrolled hydration product. – Control shrinkageinconcrete by modifyingthenature ofthehydrated – HPCisdefinedasconcrete fitforitsintendeduse. – We needtogettheinformationfrom theacademicworldtoreal world – Method specificationsare lessdesirableinthiscontextthanperformance Kevin MacDonald (Facilitator), Mike Beacham, Bjorn Birgisson, – Improve CO – Find waystouse“gray” or recycled waterby usingnanotechnologytocontrol – Develop methods toreduce theamountofwaterneeded towashorprepare – Use nanomaterialstoimprove useofmarginalandrecycled aggregates in – Investigate meanstoproduce concrete withsufficientstrength, flexibility, – Use nanotechnologytomodifycementssothattheyare more efficient,which – Develop systemsin energy-efficientinsulatingconstruction order toimprove – Tools toreduce incementmanufacturing. energyconsumption,particularly – Means ofimproving fuelconsumptionincementmanufacturing,concrete Tyson Rupnow burden. characteristics. cement paste. quickly. specifications. the amountsofcontaminantsinwater, ortolimittheireffects. aggregates andtomakeconcrete mixture workable. characteristics, andpoorabrasionresistance. aggregates withcurrently excessive claycontents,poorsoundness cementconcrete.portland Thiswouldincludemethodstoallow useof replacement. and potentialdurabilitytoensure longerlifeandlessneedforrepair and will leadtolower consumptionrates. thermal characteristicsinbuildings,especiallyhousing. systems. production, andintransportation 2 sequestration properties ofconcrete sequestrationproperties toreduce thetotalCO
2
55 I Workshop on Nanotechnology for Cement and Concrete Breakout Sessions 56 I Workshop on Nanotechnology for Cement and Concrete Breakout Sessions High Performance 2 Who Solutions Needs Invited Low fruit Who Solutions
– Enhanced mechanicalproperties. – Roadmap—International Technology Roadmap forSemiconductors. – Group/Industry/Academia. – Consortia. – Establishcomputationalnanotechnologytechniques formodelinghydrated – Identify forenhancementofmechanicalproperties. nanoparticles – Use embeddedsensorsinrawmaterialsandfinished concrete toenhance – Develop affordable nanomeasurement technologiestomonitor, control, and – Ability torecycle. – Greater cost-effectiveness. – Improved constructability. – Improved characteristicsof raw materials. – Greater consistencyinrawmaterialsandprocess control. Suneel Vanikar (Facilitator), Clark Cooper, Geoffrey Holdridge, Jack Holley, We needtoidentifywhatisavailable inthenanoworldnow andtakefrom Cement andadmixture companies,ACPA, FHWA, NSF, anyone withfunding – Use claystomodifyhydration product structures. – Beneficiate aggregates by coatingthemwithnanomaterialstoimprove – Use nanomaterialsincorporatingcolorchangeforindicatingwatercontrol – Use nanomaterialsasuniformlydistributednucleationseedsforhydration. – Modify cementconcrete portland processing tomakeitlesssensitive to – Develop innovative procedures formeasurement ofkeyparameterssuchas Felek Jachimowicz, John Melander, KrishnaRajan,Joe Tedesco, Don Weir needs. those industriesandapplytotransportation/infrastructure and/or problems tosolve. cementitious systems. production consistency, predictability, androbustness. minimize water contentincementandconcrete. bonding characteristicsandinhibitdeteriorationmechanisms. orend. start during earlyhydration inorder toflagwhensawing,texturing,orcuringcan human error. potential durability. Durability 1 Durability Low Fruit Who Solutions Needs Invited Low Fruit
– Chemistry andcomputationalnano-level modeling. – Chemistry – Development ofsensorsandhigh-techequipment. – LiaisonwithNanocem toprevent overlap. – NSFfundingisneeded. – Multidisciplined todothework. consortia – Use nanoscaledevicestomonitorandmodifyconcrete performance. – Develop tomonitorthemechanismsofdegradation. nanoinstruments – Use nanotechniquestodevelop betterunderstandingoffreeze-thaw, sulfate – Use nanomaterialstocreate self-healingmechanismswhencracksoccur. – Use nanomaterialstoimprove self-curing. – Use nanomonitorstounderstandandmonitorthemigrationofwaterin – Monitor offresh therheologicalproperties concrete withnanomonitors. – Improved knowledge required abouttheproperties fordurabilityandthe – Greater useofmarginalaggregates. – Reduced shrinking andcracking. – Improved mixingandcuring techniquesandmonitoringmethods. – Tests concrete toevaluate ofultra-highperformance properties (UHPC). – Tests topredict basedonunderstandingthemechanismsthat performance – New qualitycontrol meanstomonitorthepavement during andafter – Significantly extendedlifeuntilthefirstmajor rehabilitation. – Control ofdegradationmechanismsinaggregates. – Improved through thepaste. pastequalitytolimitwatertransport Colin Lobo(Facilitator), Mike Byers, Vic Perry, Bruce Blair, Panneer Selvan, – Dimensional stability. – Self-healing, self-curingconcrete. – Trained workforce. – Semiconductors andSemiconductor Research Corporation. Ed Garboczi, Jim Grove attack, andalkalisilicareaction mechanisms. concrete. mechanisms behindthem. cause thedeterioration. construction.
57 I Workshop on Nanotechnology for Cement and Concrete Breakout Sessions 58 I Workshop on Nanotechnology for Cement and Concrete Breakout Sessions summarize bothofthesesetstopics. tothefuturecritically important oftheconcrete industry. construction Thefollowing sections severalto manyofthem.Likewise, topicswere onlyaddressed by somegroups, buttheyare In collatingtheinformationfrom thegroups, itwasfoundthatsomethemeswere common Summary 2 Durability Priorities Solutions Needs Invited
– Test methodsthatcanbeusedtorapidlypredict andcorrelate performance – Forced internalcuring. – Control percent hydration of concrete. – Turn on andoffhydration ofcement. – Faster, betterdurability testmethodsusingnano-sensing. – Improved understandingofhydration systems. – Improving durabilityofin-placeexistingstructures through fillingmicro – Test methodsbasedonbetter understandingofattackmechanisms. – Nanomaterials couldalsobeusedforactivation ofdesired processes suchas – Nanosensors couldbeusedtomeasure various inthefield.These properties – Nanotracking canhelpaddress andnanoinstrumentation issuesrelated to – Concrete thathasalimitedfunctionallife. – Theabilitytofillorsealcracksandmicropores – Improved andexistingstructures durabilityfornew – Improved dimensionalstability measurement andcontrol – Better control ofentrainedairstability – Theabilitytoturnonandoffthe hydration process asdesired – Improved understanding,control, andmonitoringofcementhydration – Improved inconcrete understandingoffluidtransport – Improved understandingofattackmechanisms—alkalisilicareaction, delayed Peter Taylor (Facilitator), Perumalsamy Balaguru, Teck Chua,Julie Garbini, Gary Henderson, Knight,ShashiGary Gary Nambisan results withthelifeofsystem. cracks andvoids. improved curing/hydration. aggressive chemicals. would includemonitoringmechanismssuchascrackingandinfiltrationof understanding hydration inthelab. ettringite formation,sulfateattack
of thefresh concrete, followed by strength gainanddecreased permeability. Thissystemof Cement hydration isacomplexsetof interrelated chemicalreactions leadingtostiffening of Modification cement hydration value. the stillintractabledeteriorationmechanisms,suchas alkalisilicareaction, willalsobe ofgreat longer lastingconcrete structures. Methods tohelpdevelop betterunderstanding ofsome nanomaterials tomodifythepermeabilityofagiven concrete systemwillimmediatelyleadto industry.in theconstruction Again,theuseofnanotechnology-basedtoolstomonitorand mechanisms,andnonehas foundgeneralacceptance appropriate forassessingthesetransport fluids through theconcrete microstructure. At present, there are alimitednumberoftests All failure mechanismsassociatedwithconcrete durabilityinvolve of thetransportation Permeability pore fluids.Thesehave not industry. yetfoundwideacceptance inthepavement construction shrinkage-reducing admixtures are tensionofcapillary available todaythatmodify thesurface the shrinkageofhydrated cementsystems.It shouldbenotedthatcommercially available reduced. It islikelythatnanotechnologywillbeabletooffertoolsmonitorand/ormodify replaced, orrepaired. Lossestocontractorsandowners ofpavements wouldbesignificantly in termsoftimingandextent,millionsdollarswouldbesaved inslabsbeingremoved and movement withintheconcrete couldbeprevented, reduced, oratleastmademore predictable premature failure inalargenumberofpavements around serviceability thecountry. If this slabs ongrade.Shrinkage isadirect causeofcracking andwarpingleadingtofaulting in concrete inpavementsfor alargepercentage and systems,particularly ofdefectsobserved Volume changeinconcrete duetotemperature changesandmoisture lossover timeaccounts Shrinkage astraditionalsources ofhigh-qualitymaterialsaresustainability ofconstruction consumed. modify problem systemssothattheybecomeusable.Thiswillhave asignificanteffecton of theconcrete. It isbelieved that nanotechnologywillbeabletoprovide systemstocoator interfere (durability) withthefreshorlong-termproperties (constructability) properties This topicencompassesmodificationofaggregates and recycled materialsthatwould otherwise Use ofmarginal andrecycled materials All ofthesehave potentialsolutionsthrough theuseofnanotechnology. following: reduce theamountofCO As asignificantproducer ofCO ofCOReduction • • • • Accounting fororencouragingsequestrationofCO Supplementing clinkerwithothermaterials. concrete, leadingtolower consumption. Increasing efficiencyofcementalongwithimproving thequalityanddurabilityof Capturing andbeneficiatingCO 2 loadingontheenvironment 2 theyrelease totheatmosphere. Thiscanbeachieved by doingthe 2 , the cement industry isunderconsiderablepressure, thecementindustry to 2 duringthemanufacturingprocess. 2 intohardened concrete.
59 I Workshop on Nanotechnology for Cement and Concrete Breakout Sessions 60 I Workshop on Nanotechnology for Cement and Concrete Breakout Sessions largely fromofmaterialsmanufacturers thepointofview andusers. This sessionhasbeenabletoupdatethetopicsandprioritiesbasedonneedaccessibility, All ofthesetopicswere identifiedinthe roadmap developed attheworkshop heldin2006. Closing durable concrete structures andpavements. ofa systemashydrationproperties progresses willgreatly easetheabilitytobuildandmaintain parameters.Once again,developmentperformance ofnanodevicesthatcanreport thein-situ future performance. Tied tothesemodelsistheneedcharacterize andmonitorthecritical and validating thesemodelsinorder toimprove understandingofthematerialsandpredict ofdifferentthe performance cementitioussytems. Work isneeded tocontinuedeveloping available, allowing forthedevelopment ofmore rigorous modelsthatdescribeandpredict across several orders ofmagnitude. Such computationalresources are now becoming meter scale.Alargeamountofcomputingpower isrequired toproperly modelthematerial Hydrated cementpasteisheterogenous andcomplexboth atananometerscaleand Computational andNanodevices Modeling andSensors use ofconcrete willbesignificantlysimplified. forconstruction effectively provide moisture forhydration from internalsources ratherthanexternal,thenthe an environment forhydration tocontinue.If nanotechnologyisabletoprovide ameansto scheduleandeconomics.Curing countertotheconstruction runs isrequired toprovide industrial materials,andtheneedtokeepaconcrete wet andwarmforseveral weeks often cementitious systems.Hydration cementisrelatively ofportland slow compared toother associatedwithhydrationA property istheprovision ofso-called“internalcuring” to Curing significantly enhanceconstruction reliability andefficiency. with toolstomonitorhydration and,preferably, meanstocontrol theratesofhydration, will finished products. Development ofabetterunderstandingtheprocesses involved, associated exposed. Unexpected changesinstiffeningandorstrength gain regularly impactthequalityof Rates are affected by thematerialswithinsystemand by theenvironment towhichitis reactions isrelatively poorlyunderstoodandgenerallyuncontrolled onceithasbeeninitiated. of trackingamixture degree ofhydration inreal timewouldreduce theriskofpremature critical parameters,suchas crackriskanddurability, isunreliable. Devices thatprovide ameans concrete for quality control purposes are empirical and have poor repeatability. Measurement of technology isintherealm ofmodelingandsensors.Many testscurrently conductedon The otherarena where nanotechnologyhasthepotentialtosignificantlychangeconcrete permeabilityofconcretesurface andso increase itsdurabilitywillbeinvaluable. responsible forunexpectedstiffening. Development ofimproved materialstohelp reduce the process andlimitingtheprocesses by acceleratingthephasesthatcontributetoperformance Even toenhancethe cement grainsmaybenefitfromhydration modificationoftheirsurfaces enhancesustainabilityanddurability ofconcrete.hydration mechanicswilllikelyfurther cementitiousmaterialsandthestudyoftheirdirect effectson The useofsupplementary air, ormodifyshrinkagebehaviorare ripefornanomodificationtooptimize theirperformance. of concrete. Chemicaladmixtures thatare usedto modifyworkability ofthemixture, entrain thereLikewise, appearstobegreat potentialininvestigating andmodifyingtherawmaterials described above. manipulations ofthissystemmaymakesignificantcontributionstoaddressing theneeds cement pastefallsfirmlyintothe realm ofnanotechnology, andthetoolspotential On theotherhand,structure andhydration mechanicsoftheindividualphasesportland questionable. whole somewhat is inthetensorhundreds ofconcrete ofμm,makingtheneedtostudynanoproperties asa insize fromvary μmsizes uptotensofmm.The “critical flaw” size ofmostconcrete mixtures and more porous thanthatformed50μmawayfrom theaggregate Aggregate surface. particles fraction. Hydrated cementpastethatformsnearcoarseaggregate tendstobeweaker particles ofeachtheconstituents,notleastwhichispaste composition andproperties heterogenous mixture ofmultiphaseconstituents.There are significant variancesin When prioritizingtheseneeds,several factorsneedtobeconsidered. Concrete isa inroads intotheaforementioned needsinthenearterm. It was believed that nanotechnology and nanoscience would have the means to make significant thatmustbeaddressed through scientificexploration: industry construction Several themeswere common/important apparent asimmediateneedsfortheconcrete Common Themes and Priorities Outcomes • • • • • • • Crack prevention (Shrinkage), Use ofmarginalandrecycled materials, Reduction ofCO Improved andperformance. modelingofproperties Provision ofcuring,and Modification ofcementhydration, Reduced permeability, 2 loadingontheenvironment,
61 I Workshop on Nanotechnology for Cement and Concrete 62 I Workshop on Nanotechnology for Cement and Concrete Outcomes waiting forseveral years forsignsofdistress. However,environment, andoftenthisistrue. there isnogoodwaytobesure of ofthis,short well-proportioned mixture with anadequateairvoid systemwillbeabletowithstandthe toassistwithpermeability.applied tothesurface Generally, itisassumedthatawell-hydrated, sawingisbasedonanestimateby anexperiencedoperator.to start No treatment further is ride qualityandincreasing theriskofjoint-related failures later. Often thedecisiononwhen leading tolossofserviceability. If sawingistooearly, thenthejointsare raveled, reducing temperature drop andlatermoisture loss.If sawingistoolate,thenrandomcrackingoccurs, Joints hourslatertoallow are afew theslabtoshrinkdueinitial sawnintothesurface hot duringearlyhydration, oftencausingtheslabtosetatwell above ambienttemperature. and evaporation ratesare high,thencracking isprobable. Themixture isexothermic andgets are appliedtosealinwaterforcuring.No additionalwaterisprovided. If theweather ishot provide skidresistance. Aftersome timeofexposure totheatmosphere, curingcompounds Voids are onthesurface filled(orcovered over) isthentextured by handandthesurface to handling, makingitdifficulttoconsolidate. the mixture ingredients, thenthemixture maystiffenbetween thetimeofbatchingandfinal enough toretain If uncontrolled shapewhenunsupported. chemicalreactions occurbetween walking adelicatebalancebetween fluidenoughtobehandledandconsolidated,butdry wet, thenedgeslumpwilloccur, compromising theintegrityofpavement. We are therefore moves pasttheconcrete, itishopedthattheconcrete retains itsshape.If themixture istoo confirm thestateofhydration andthein-placequalityofair void system. Once thepaver removed. Only rarely are testsconductedoncethepavingmachinemoves pasttheconcrete to to remove oversized airbubbles,withtheassociatedriskthatdesirablebubblesare also and significantenergyis required tofilltheformsand remove large voids. Vibrationisapplied mixture Thisstiffmixture proportions. isforced intoitsfinalshapeusingheavyequipment, whether themixture containsthecorrect ingredients withinreasonable boundsofthedesigned workability of the mixture or the state of the air void system. No means are available to confirm fine airbubblesneededforfrost protection. Standard testmethods donot reliably indicatethe has beendifficulttoensure adequateand/oruniformmixingandtoentrainasufficiencyof At present, arelatively stiffmixture isdelivered toitspointofplacement. Because itisstiff, slipform paving. A scenarioforthefuture maybevisualized by referring system—concrete tooneconstruction A Vision highest priorityfrom theabove list. elsewhere. Theseare likelytobetheprimedrivers inthenearterm,makingCO industries, aggregate sources are declining,andleadingtechnologyisbeingreported from now tofacethesamedemandsinthatCO starting and by competitionfrom is globalmanufacturers. TheU.S.concrete industry construction processes have beendriven by theneed forbettersafetyandreliability, reduced emissions, significantly different from onebuiltin1960.Thechangesdesignandmanufacturing The otheraspecttothisconsiderationisthatofsustainability. Acarbuiltin 2007is improved reliability andmore rapiddevelopment ofinnovative materialsandcombinations. failure significantly. Tools thatusenumericalmodelstopredict willleadto systemperformance 2 isnow aglobalproblem impactingmany 2 issuethe 7 this report. In 1992,itwasestimated thatreplacement ofthedeteriorating builtenvironment savings of$7billionperannum, worldwide,canbeachieved by meetingtheneedsdiscussedin Based onthefigures discussed intheintroduction, itisnotunreasonable toestimatethata Collaborative effort then manyofthefailures currently occurringwillbesignificantly reduced. involved. Realistically, ifwe candealwithworkability control, shrinkage,andpermeability, way thatconcrete pavements are resulting constructed, inincreased reliability forallparties Based onthisvision,onecanconceive thatnanotechnologymayfundamentallychangethe early tofacilitateplanningforrepair ormitigation. state oftheconcrete, andshouldcracksordeleteriousreactions occur, theycanbereported cracking, andtheneedforjoints.Thesensorsembedded inthesystemcontinueto the report incorporated tominimize thermalstresses intheslab, reducing further theriskofwarping, joints andcontrolling warping.Ideally, methodstocontrol temperature variations canalsobe reduced oreliminated,thussignificantly reducing theneedfor, orincreasing thespacingof, shrinkageis nanomaterials control thestructure ofthehydrated cementpastesothatdrying a statewhere theconcrete theintendedtrafficfordesignedtime. Other isready tocarry concrete wouldnotbecompromised. Internal curingmoleculesthenpromote hydration to redundant. Thissealantwouldbebelow therefore, thesurface; theskid resistance ofthe if asufficiently robustsealantcanbedeveloped, thentheneedforentrainedairmaybecome paste tosealitupandprevent future fluidpenetrationanddurability-related failure. Indeed, where millimetersintothesurface, theyinteractwiththehydratedpenetrate afew cement are TheirsmallsizeAnother setofnanoparticles allows thenappliedtothesurface. themto accelerates hydration tocausefinalsettingandinitialstrength development. basis forqualitycontrol andqualityassurance. Texturing isappliedandanothersignalfurther not occur. Sensors continuetoreport thestateofmixture behindthepaver providing the concrete tostiffensignificantlybefore itisexposed bythepavingmachine. Edgeslump does the hydration andhydration control isinitiatedandacceleratedtocausethe nanoparticles, report therequired airvoid parametershave beenachieved. At thistime,asignalissentto unwanted largeairvoids, andvibrationisstoppedassoontheinternalnanosensors and relatively easilyformedintoitsfinalposition. Minimal vibrationis required to remove the concrete andthemixture isnotstiffening.Themixture ishandled bylightequipment degree ofhydration. Hydration hasactuallybeenstoppedby nanomaterialsmixed into Internal monitoringnanodevicesprovide continualloggingoftheairvoid systemandthe fluidmixture thathasbeeneasilymixedA very intransitisdelivered tothepointofplacement. nanotechnology. Consider thenanalternative approach thatmay, indeed,bepossiblewiththeassistanceof despite thepotentialpitfalls,systemiseconomicallyandtechnicallyviable. do managetoproduce manyhundreds ofmilessuccessfulconcrete pavingeachyear, and, limited knowledge ofthecomplexitiesbehindsystemtheyare working with.However, we often madeby peoplewhohave notreceived adequatetrainingforthetask,andwhohave life ofthepavement ifbaddecisionsare made.Adding totheriskisthatthesedecisionsare making criticaldecisionsbasedonlimitedinformation,withsignificantimplicationsthe This descriptionhassoughttoindicatethatslipformpavingisaseriesofcompromises and NSF CivilInfrastructure (CIS)Strategic Issues, NSF94-129
63 I Workshop on Nanotechnology for Cement and Concrete Outcomes 64 I Workshop on Nanotechnology for Cement and Concrete Outcomes any oftheabove andshare agenciescanfindpartners data, resources, andneeds. The above discussionpointstotheneedforaneutral, central,clearing-house resource where between by inorder collaborative efforts toleverage the resources available. Collaborationis required When consideringthemagnitudeofissues,itisclearthatneedscanonlybeaddressed However, thework alsoofferssignificantenvironmental andsocietalbenefits. Thus, the value ofpursuingthiswork isclearlyjustifiedalone. from aneconomicviewpoint preventing premature failures wouldtherefore beintheorder ofseveral billionperannum. was goingtocost$20.6trillionintheUS • • • • • • conducted atthehighestlevel. Funding agenciestoallow sufficient resources to be available forthe research tobe developed forothermaterialsthatwillbeofbenefittothestudycementitioussystems. tomakeuseoffindingsandapproaches opportunity Other industriestotakeevery work isnotrepeated unnecessarily. Information providers so that there is appropriate sharing of findings to ensure that seminal work. safely andeffectively—both atanoperatorlevel, andforfuture researchers tocontinuethe Education technologieshow institutionstoteachusersofthenew theymaybeutilized Specification authoritiestoallow innovations tobeacceptableincontractdocuments. to bear. Research institutionstoensure thatthebestavailable mindsandresources canbebrought 7 . Mitigation of this need in new construction by. Mitigation construction ofthisneedinnew covered by theseresearch miniconsortia: and keyfundingagencieswithintheUnited States andEurope. Thefollowing topicswillbe points forresearch where consortia, technicalinputandfundingwillbesoughtfrom industry In addition,thekeypriorityresearch areas identifiedinthisworkshop willbeusedasfocal The following planshave beendeveloped: Plans for thefuture • • • • • • • • • • • • Establish aninternationaluniversity-based research topromote andlead consortium mix concrete industry, federalagencies,andresearchers inthisarea. board willincluderepresentatives ofthecementandchemicaladmixture industries,ready- Consultative Board forAdvancing Nanotechnology (NNICBAN)asappropriate. The It isplannedthatthisboard willdevelop intoaNational Nanotechnology Initiative boardEstablish anIndustry tohelpsteerfuture decisionsregarding research inthisfield. Computational modelingandsensorsystems tomonitoranddescribe systemperformance. cement concrete.in portland Development ofnanotechnology-basedsolutions tomonitorandmodifyratesofhydration Nanomodification cementconcrete of portland to reduce permeability. Nanotechnology forreduced cement concrete. shrinkagebehaviorofportland cementconcrete.materials inportland Development ofinnovative technologiestoenhancetheuseofmarginalandrecycled Use ofnanotechnologytoreduce CO development ofamodelforthehydration process. research outcomes.Organize around grandchallengeproblems, largerconsortia suchas the university-based researchandintermediate-term withafocusonshort-term consortium, Develop approach tofosterresearch aconsortium-based through theinternational, efforts during research inprogress. and research outcomes,whichwillalsoallow secure communicationsbetween researchers Establish anInternet-based centraldatabaseandclearinghouseonkeyresearch inprogress that mayacceleratetheproposed activities. reviews ofwork conductedinotherfieldsandindustriestoseekmethodsapproaches and issuesraisedatthismeeting.Thiswork willalsoincludeconductingextensive literature Commence work ondeveloping detailedwork statementsaimedataddressing theneeds possible approaches totheneedsraisedatthisworkshop. scientists working innanotechnologyandnanosciencetodiscusstheirwork andtheir Plan anotherworkshop forthesummer/fallof2008toprovide for anopportunity computational modelingandthinfilmscoatings. inpolymersandinnovativewith expertise materialprocessing, on aswell asexperts materials,includingconcrete onconstruction pavingmaterials,materialscientists experts in nanotechnology-basedcementandconcrete research. willinclude Thisconsortium key research entitiesthatbringtogetherthebroad knowledge neededfor thebreakthroughs nanotechnology-based concrete research. It isextremely toformacoalitionof important 2 loadingfrom cementplantsontheenvironment.
65 I Workshop on Nanotechnology for Cement and Concrete
8:00 am–8:30 Objective: Appendix A:Agenda Appendices 1:00 pm–1:45 12:00 –1:00pm 11:30am -12:00am 11:00am –11:30am 10:45 am–11:00 10:15 am–10:45 9:45 am–10:15 9:25 am-9:45am 9:15 am–9:25 8:55 am–9:15 8:45 am–8:55 8:30 am–8:45 Sponsors: Provide nationaldirection onareas ofpriorityinterest andcollaborationbetween industry andpublicagenciesspecificallyforcementconcrete. industry Council, through theNational Nanotechnology Coordination Office Technology Subcommittee (NSET) oftheU.S.National Scienceand Technology Foundation, inCooperationwiththeNanoscale Science,Engineering, and The National Concrete Pavement Technology Centerandthe National Science Workshop onNano Technology for Cement andConcrete
North Fairfax Drive,FDIC, 3501North Arlington, VA
The Future ofConcrete The Nano-Engineering ofUHPC&Structures New Functionalities for the Building Industry Nanocem -European Efforts Nano House overarching themesoftheiragencies’/companies’ areas ofinterest) Lunch Vic Perry, Bruce Blair –Lafarge&Dr. Franz-Josef Ulm -MIT Dr. Laurent Bonafous–Essroc-Italcementi Dr. Richard Livingston,FHWA Dr. Felek Jachimowicz, Vice President ofResearch, WR Grace Break Vagn Johansen, Nanocem Henderson,Gary FHWA. Dr. Mike Roco, National Nanotechnology Initiative Dr. Clayton Teague, National Nanotechnology Coordination Office Tom Cackler, CP Tech Center, Iowa State Univ. Welcome Coffee should beprepared toshare briefcomments[3to5minutes]onmain Round tablediscussion Nanoscience ofHighway Materials Construction FHWA Perspective onNanotechnology inConcrete Snapshot oftheNational Nanotechnology Initiative
September 5,2007 September
(Each participant group [agency/company] (Eachparticipant
67 I Workshop on Nanotechnology for Cement and Concrete 68 I Workshop on Nanotechnology for Cement and Concrete Appendices 3:45 pm–4:45 5:00 pm 1:45 pm–2:15 2:15 pm–3:15 4:45 pm–5:00 3:15 pm–3:45
Meeting Adjourned Next steps:Discussion Reports from breakout teams Breakout sessionstoidentifypriority topics Roadmap forResearch Dr. BjornBirgisson, Royal Institute of Technology for collaboration) Break • • • Sustainability High Performance Durability
Tom Cackler, CP (Goal istoprioritize several goodtopics Tech Center (Two groups pertopic)
Clark Cooper Teck Chua Rita Chow David Carson Tom Cackler Mike Byers Jeffrey Bullard John Brighton Laurent Bonafous Bruce Blair Bjorn Birgisson Charles Beatty Mike Beacham Perumalsamy Balaguru Jamshid Armaghani James Alleman Appendix B:Attendees Richard Livingston Steve Kosmatka Knight Gary Vagn Johansen Felek Jachimowicz Al Innis Jack Holley Geoffrey Holdridge HendersonGary Fred Hejl Jim Grove Brian Green Ed Garboczi Julie Garbini Peter Deem National ScienceFoundation-Civil, Mechanical andManufacturing Florida Rock Industries Environmental Protection Agency Environmental Protection Agency National Concrete Pavement Technology Center Indiana ChapterAmerican Concrete Pavement Association National Institute ofStandards and Technology Iowa State University Essroc-Italcementi Lafarge Royal Institute of Technology-Sweden University ofFlorida Pipe Association Rutgers University Florida Concrete Products Iowa State University Materials Research Board Task Force onNanotechnology-Based Concrete Center Innovation/Engineering Federal Highway Administration Portland Cement Association Heidelberg Nanocem WR Grace Holcim Lafarge National Nanotechnology Coordination Office Federal Highway Administration Transportation Research Board National Concrete Pavement Technology Centerand Transportation US ArmyCorpsofEngineers-Engineering Research andDevelopment National Institute ofStandards and Technology Ready Mix Concrete Research andEducation Foundation Holcim
69 I Workshop on Nanotechnology for Cement and Concrete Appendices 70 I Workshop on Nanotechnology for Cement and Concrete Appendices Don Weir Leif Wathne Jerry Voigt Suneel Vanikar Joe Tedesco Clayton Teague Peter Taylor Panneer Selvam Uwe Schutz Tyson Rupnow Mike Roco Randell Riley Daniel Rardon Krishna Rajan Vic Perry Shashi Nambisan John Melander Shahran Mehrvarzi Kevin McMullen Kevin MacDonald Colin Lobo Giant Cement American Concrete Pavement Association American Concrete Pavement Association Federal Highway Administration University ofFlorida National Nanotechnology Coordination Office National Concrete Pavement Technology Center University ofArkansas St. Lawrence Cement National Concrete Pavement Technology Center National ScienceFoundation Illinois ChapterAmericanConcrete Pavement Association PPG Industries Iowa State University Lafarge Iowa State University Portland CementAssociation Federal RailAdministration Wisconsin ChapterAmericanConcrete Pavement Association Cemstone Products National Ready Mix Concrete Association
CP Tech Center Iowa State University 2711 South Loop Drive, Suite 4700 Ames, IA 50010-8664
CONTACT Peter Taylor 515-294-9333 [email protected]
Photo courtesy of Chris Bobko and Franz-Josef Ulm, Massachusetts Institute of Technology, 2007