Current Admixture Technology
Count on Concrete for Long Life and Value – Current Admixture Technology2008 Annual Virginia Concrete ConferenceCount on Concrete for Long Life and ValueSheraton Park South Hotel, Richmond, VAMarch 6 - 7, 2008César A. Constantino, Ph.D.Director of Process & Qualitycconstantino@titanamerica.comCurrent Admixture TechnologyBackgroundChemical Admixturesy NextGen High-Range Water Reducers(Superplasticizers, aka Super P)y Viscosity Modifying Admixturesy Rheology-Controlling Admixturesy Air Detrainer Admixturey Compatibility of Admixture SystemsConclusionsContents2Count on Concrete for Long Life and Value – Current Admixture TechnologyACI 116R-00 definitiony A material other than water, aggregates, hydraulic cement, and fiber reinforcement,Backgroundy used as an ingredient of a cementitiousmixture to modify its freshly mixed, setting,or hardened properties and that is added tothe batch before or during the mixing.BackgroundAdmixtureCount on Concrete for Long Life and Value – Current Admixture TechnologyImageImage Source:Source: www.cement.orgwww.cement.orgIMG1057IMG1057Fly Ash ParticlesCount on Concrete for Long Life and Value – Current Admixture TechnologyV.S. Ramachandran:Scanning electron microscope (SEM) micrograph of flyash particles. Although most fly ash spheres are solid,some spheres are hollow cenospheres (as shown)54Image Source: www.cement.orgIMG12188y important group ofadmixtures used in smallamounts Liquid Admixturesy Water soluble or emulsifiedsystemsy Accelerators, retarders, water reducers,superplasticizers, etc.y Air entraining, pumping aids, coloring, alkaliaggregate expansion-reducing, and others Chemical Admixtures61
Count on Concrete for Long Life and Value – Current Admixture TechnologyAir EntrainersLiquid Water ReducersStandard SpecificationsHigh-Range Water Reducers n ControlMid-Range Water Reducer1990s2000sViscosity ModifiersPolycarboxylate (PC) HRWRSelf-Consolidating ConcreteNextGen PC HRWR, Air Detrainers, and CocktailsAdmixture-RelatedInnovations TimelineCount on Concrete for Long Life and Value – Current Admixture Technologyy Air Entraining Admixturesy Water-Reducingy Retardingy Acceleratingy Water-Reducing and Retardingy Water-Reducing and Acceleratingy High Range Water-Reducingy High Range Water-Reducingand RetardingImage Source: www.cement.orgIMG12188Specifications for others?Chemical Admixtures78Count on Concrete for Long Life and Value – Current Admixture TechnologyComprised of four major groupsChemical AdmixturesHRWR (Super P)y Sulfonated naphthalene-formaldehyde condensate(SNF)y Sulfonated melamine-formaldehyde condensate(SMF)y Modified lignosulfonate (MLS)y eSource: Joe Daczko, BASF Admixtures1970HRWR (Super P)1980HRWR (Super P)Count on Concrete for Long Life and Value – Current Admixture TechnologyDesign molecules for specific performance andspecific cement chemistries1990200010Count on Concrete for Long Life and Value – Current Admixture TechnologyResults of PC HRWRmolecular designy Dispersion efficiencyMolecular attributes can be altered to affect performance(via synthetic chemistry) Electrostatic repulsion Steric repulsiony Slump retentiony Control over settingtimey Early-age strength Density of side chain grafts Density of charge on backbone Molecular weight of side chain Molecular weight of backboneBackbone and side chainchemistry are by designAtomic Force Microscope (AFM) picturePC HRWR Molecule in ConcreteSource: Joe Daczko, BASF AdmixturesSource: Joe Daczko, BASF AdmixturesNextGen PC HRWR11NextGen PC HRWR122
Count on Concrete for Long Life and Value – Current Admixture TechnologyVs.etout SWith ation!drRetaViscosity ModifyingAdmixturesSource: BASF AdmixturesNextGen PC HRWRViscosity Modifying Admixtures13Count on Concrete for Long Life and Value – Current Admixture TechnologyCount on Concrete for Long Life and Value – Current Admixture TechnologyA material added to concrete that changes itsviscosity and improves the stability of the mixtureRolling edgey Cellulosey PEG – Glycol derivativey Natural Gums(Welan, Diutan, Guar)Aggregateparticles haveseparatedfrom mixturevs.Flat edgeSource: BASF AdmixturesIncrease inViscosityViscosity Modifying AdmixtureSource: BASF AdmixturesAggregate particles aresuspended within the mixture andare present all the way to theperimeter.Viscosity Modifying Admixture1516Count on Concrete for Long Life and Value – Current Admixture TechnologyPerviousNo VMAPerviousVMA5 drops5 dropsSource: BASF AdmixturesSource: BASF AdmixturesVMAsRheology-ControllingAdmixturey Provide cushion to aggregate particlesy Add more “body” or “cream” to concretey Keep particles suspended, reduced segregationViscosity Modifying Admixture17Rheology-Controlling Admixture3
http://www.wikipedia.comy The study of the deformation and flow of matter underthe influence of an applied stress, which might beshear stress or extensional stress.Rheometer Higher intercept pointscorrespond to LOWER slumps The slope of the line correlatesto viscosity A greater slope signifies ahigher viscosityy An H-shaped impeller spins in abucket of concretey Data is converted to torquey Torque data is then collected forvarious impeller rotation rates2520scouisTorque 11.084RotRate 6.1346re v2R 0.9905 moLowerSlumpRheologyCount on Concrete for Long Life and Value – Current Admixture Technology The point at which the lineintercepts the torque axis (yintercept) correlates to slump.Torque (Nm) - Shear StressCount on Concrete for Long Life and Value – Current Admixture Technology15Sa me105H0,mps lusityyViscocosite vismp,r sluighe0sam0.511.5RotRate (rps) - Shear RateceReferenIBB Concrete RheometerBASF AdmixturesRheology-Controlling Admixture19Rheology-Controlling Admixture20Count on Concrete for Long Life and Value – Current Admixture TechnologyAir Detrainer AdmixtureWithAdmixture effecty Lowers force required to initiateflow, without affecting the viscosityy Improves response to vibrationy Lubrication effecty Enhances consolidationWithoutRheology-Controlling Admixture21Air Detrainer AdmixtureCount on Concrete for Long Life and Value – Current Admixture TechnologyNot recommended for use in air-entrainedconcrete Reduces the air content of concrete mixturesHelps to maintain design strengths of concretemixturesMay reduce rejected load potentialOther benefits?Compatibility ofAdmixture Systemsy Interior flatworkAir Detrainer Admixture23Compatibility of Admixture Systems4
Count on Concrete for Long Life and Value – Current Admixture TechnologyCombination of Water Reducer and HRWRCount on Concrete for Long Life and Value – Current Admixture TechnologyCombination of Mid-Range and Retardery Low water content concrete, i.e. zero slump (initialwater content is critical)y Add Type A (2.0 oz/cwt) to increase to 2 in slumpy Add type F (9.0 oz/cwt) to increase to 11 in slumpy Higher strengths, lower shrinkagey High slump retentiony Good pumpabilitySource: Richard Szecsy, Lattimore Materials Company, L.P.y High temperatures, low humidityy Longer working timey Better control over set timey Typically 8.0 oz/cwt and 2.0 oz/cwt, respectivelySource: Richard Szecsy, Lattimore Materials Company, L.P.Admixture CocktailsAdmixture Cocktails2526Count on Concrete for Long Life and Value – Current Admixture TechnologyCombination of hydration stabilization admixture(HAS) and accelerator and HRWRy Job Constraints/Specifications 3000 psi in 6 hrs, Type I/II cement2 yd3 bucket placement, 8 yd3 per truck45 min haul to jobNo staging of trucks, tight jobsiteConclusionsy Admixture Sequencing Type F added to truck Type C added after Type F Type B added after Type F and CSource: Richard Szecsy, Lattimore Materials Company, L.P.Admixture CocktailsConclusions27Count on Concrete for Long Life and Value – Current Admixture TechnologyChemicalAdmixturesWaterFineAggregateFly AshPortlandCementSlagFibersCoarseAggregateSilica FumeCount on Concrete for Long Life and Value – Current Admixture TechnologyNextGen High-Range Water Reducers(Superplasticizers, aka Super P)Viscosity Modifying AdmixturesRheology-Controlling AdmixturesAir Detrainer AdmixtureCompatibility of Admixture SystemsChemicalAdmixturesConcrete29Conclusions305
Count on Concrete for Long Life and Value – Current Admixture TechnologyThank Youcconstantino@titanamerica.comThank You316
Current Admixture Technology 2008 Annual Virginia Concrete Conference Count on Concrete for Long Life and Value Sheraton Park South Hotel, Richmond, VA March 6 - 7, 2008 César A. Constantino, Ph.D. Director
Admixture Systems 3 from Master Builders Solutions Having the right admixture partner W is vital to the success of any concrete producer. of Admixture Systems and has been providing intelligent solutions to the construction industry since Masterthe early 1900s. Admixture Systems from Ma
Patterson, 2005; Smith and O’Brien, 2005). High levels of LD are produced by admixture at loci that have different allele frequencies among the involved populations (Nei and Li, 1973). Because of recombination, this particular type of admixture LD (ALD) de
PRODUCT DEVELOPMENT, APPRAISAL AND TESTING OF A NEW AND IMPROVED DRYING SHRINKAGE REDUCING ADMIXTURE FOR CONCRETE Hairul Sarwono, BappSci Materials Science (Hon)1, 2Takumi Sugamata , Paul Macreath 3 1 Chemist for Admixture Systems, BASF Australia Ltd Product Engineer, Admixtur
of retarding admixture on the surface of the cement particles. The large admixture anions and molecules that are adsorbed on the particles hinder further reaction between cement and water, that is, they retard setting. They slow down the rate of early hydration of C 3 S. Later, as a result of the
Anti-Microbial Admixture (AMA) How Does It Work? 1. Anti-Microbial Admixture (AMA) integrates permanently into the concrete structure 2. Micro-organisms come into contact with the concrete surface and are destroyed 3. The AMA prohibits further growth of micro-organisms 4. The resul
Dec 04, 2019 · admixture dosage Higher strength early ages Increased heat of hydration Shorter time-of-set. Enhanced Early-Age Strength Development: Accelerating Admixture . Reference Mix: 564 lb/yd. 3. po
Oct 09, 2018 · the same infusion bag, or at the Y-site junction where two or more IV lines meet. Intravenous admixture incompatibilities occur between two drugs, drug and diluents or between drugs and materials of IV containers.[1] The number of IV medications continues to expand and the need to administer different IV drugs as
Barbara Norbal deserves special thanks for her encouragement, patience and love. You have been there for me throughout the last four years and you have helped to keep me going. Finally, I would like to thank my supervisors, Rachel Tribe and Jane Lawrence. For their commitment and guidance I will always be grateful. I confirm that the work contained in this thesis is original except where other .
