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JUTA-26-1992 0920 FF.OM R0014ESTAP HOP,TH VALLEY TO 16 15104626283 F.04 Technical o UILMH ASTM SPECIFICATIONS FOR FLY ASH Number 4 Like all materials used in the production quality have water demands approximating 90 of concrete. fly ash must meet the stringent percent of the cement control. requirements of ASTM specifications. Fly ash Autoclave expansion forces total cemen- specifications are addressed under ASTM titious hydration under high temperatures and r-AIA"Fly Ash Anti Raw Or(.nicined Natural pressures and gives an nerurntr determina- Pozzolan For Use As A Mineral Admixture In tion of long term expansion characteristics of Portland Cement CnnrretP.".While lheePatan- fly ash cnnr.retis dards are continuously under review and Uniformity requirements for the specific subject to change; a reprrsenintion of this gravity and finrnrss of thn fly Anh ensure a specification.current atthetimeofthis writing. level of consistency of the fly ash enabling follows this article. uniform production of concrete. The specifications are categorized by Optional Chemical Requirements: chemical and physical properties anti scan• MgO limitation has been deleted from this dnrcl and optional rrquiremrnts. Standard specification. History has failed to provide a requirements are imposed for all fly ash link between the MSO content and expansion; produced while optional conditions are therefore the autociave expansion lest is applied only whrrecertain requirements exist actually used to measure the potential Standard Chemical Requirements: expansion. Snmmotion of major oxides is denoted by Available alkalies are measured as avail- SiO2, A1203 and Fe2O3 and functions as the able in a saturated lime gelatin.This specifi- major difference between class F and class C cation i5 recommended only where the threat fly ash.Althnugh not expressly addressed,the of alkali-aggregate reactions may be . 20 percent Iowa requirement of these oxides encountered. in class C fly ash allows for an increased level Optional Physical Requirements: of lime(CaU). Multiple factor is the product of fineness times , , cvnwrit limitatinn is hascd on mini. LOX The intent is to prevent both fineness and mizing expansion during hydration. Ulf from reaching specification limits simul- Mointure. mnte.rlt is limilcd to maintain innrously and is a method of maintaining flowability, although values around one per- unlfurtuity. teal ales cause tion(LOI) i uts. The increase a drying shrinkage test Loss on ignition(L011 is a measure of the mlasur!g the shrinkage effects of the.Fly ash in unburned rarhnn vtonlent of the fly ash. It is a test mortar sample.Most high quality fly ash desirable to maintain the lowest level of LAl will actually reduce the drying shrinkage in possible, especially for an air entrained con- concrete. crate because the carbon absorbs the air- Air entminingadmixture demand reflects entraining agent rendering it unavailable for the effect of fly ash on air entraining admixture dispersal throughout the eerie A law LOI is also and encompasses changes in fineness and desirable for aesthetic reasons to prevent 1.01.LOI may be the prime culprit affecting the discoloration of the concrete. LOI for class F ability to entrain air. Fly ashes with LOi fly ash will likely be reduced to six percent at under one Twirrent generally do not effect the next writing of this specification. admixture demand significantly. Standard Physical Requirements: (anent nikali rrnction measures the FlnenrsR- TI-P aperifiration planes an Upper effectiveness of fly ash in reducing alkali- limit on coarseness of fly ash of 34 percent aggregate reaction using very high alkali ce- retainedonthe nomhcr325si(vn Maintaining meat and reactive ground pyrex glass as uniform fineness of the fly ash is most impar- aggregate.This test should only IN usatl when 0 tart in producing quality nonerete. alkali-aggregate conditions are suspected. Pozzolanic activity with cement is a ASTM specifications fully cover require. measure of the reartiVity of fly ash in a mortar merits for fly ash in pnrtland cement concrete mix whore 35 percent by volume of cement is and provide for the use of uniform.well tested replaced with a like volume of fly ash.The test mntrrinle fnr fly ash concrete production. is useful fur measuring pumulauic activity but For further information or specific ques- not tar predicting concrete performance. lions regarding ASTM specifications for fly Pnrzolanir. activity with lime is again a ash,contactyournearest Pozzoianictechnical measure of the pumolanic activity of the fly reprnsentalive_ ash being tested and Is an indication of its reactivity with the type of lime tested. (continued on back) Water requirement is on important test indicating the capacity of fly ash to reduce water demand. Most active fly ashes of good _ Ata?N,A e41T1711001 ohinIA • rAl IrOCNIA • eOLOOADO• IVANO• MONTANA NEVADA • OREGON A SOUTH DAKOTA• WASHINGTON • WYOMING • UTAH TELEr HONE.LOCAL zn,0320.INSIDE WASHINGTON IatWl 562 5194