AASHTO Subcommittee on Materials (SOM) 2016 Fly Ash Task ...sp.materials.transportation.org/Documents... · Ø Forty-four Agencies also identified using fly ash in areas such as flowable

*Typicalflyash

AASHTO Subcommittee on Materials (SOM)

2016 Fly Ash Task Force Report

November 4, 2016

*Pictures from: FHWA, Fly Ash Facts for Highway Engineershttps://www.fhwa.dot.gov/pavement/recycling/fach00.cfm

*Microscopicphotographsofflyash((left)andPortlandcement(right)

AASHTO Subcommittee on Materials (SOM) Fly Ash Task Force Report

Table of Contents

November 4, 2016

I. Executive Summary 1

II. Fly Ash Survey Summary 2

III. Summary of Policy Changes and Research Activity 6 Happening Nationally

IV. Identified Short and Long Term Impact on the 8 Transportation Industry

V. Review of Emerging Technologies, Strategies and 10 Products

VI. Potential Future Research Needed 11

Appendices Appendix A. Myths/Truths on Fly Ash Issue 12 Appendix B. Task Force Members 13 Appendix C: Referenced Documents and Research Reports 14 Appendix D: Agency Fly Ash Survey Results 15

AASHTOSOMFlyAshTaskForce2016 1

I. Executive Summary

A Task Force was convened at the 2016 meeting of the AASHTO Subcommittee on Materials (SOM for the purpose of documenting the issues facing the coal industry and their impact on the production of fly ash, especially as related to use in structural and paving concrete by the DOTs. The results show that the concern with fly ash supply is not a minimal or regional issue. It also shows that some Agencies are responding with a combination of immediate changes and long term research to address the difficulties they are encountering. Agencies identified the need for increased flexibility and the need to be proactive in response to fly ash concerns. Many noted that they anticipated the use of SCMs (supplementary cementitious materials) to increase due to ASR (alkali-silica reactivity) concerns and desire for sustainability/durability. Therefore, a number of State DOTs have already started sponsoring research looking at alternatives to fly ash in the future.

The Task Force’s efforts included a survey that was sent to all State DOTs, the Federal Aviation Administration (FAA)’s Pavement Group and the Federal Department of Defense (U.S. Army Corp of Engineers). The survey had 52 respondents: 46 States, DC DOT, Illinois Tollway, Western Federal Lands(WFL), the Ministry of Transportation Ontario, Canada (MTO), FAA and DOD(COE). The survey asked if the Agency had an issue with fly ash in the past 4 years, the class of fly ash that was the concern and what if anything the Agency was doing to address the issue. Over 80% of those that responded indicted issues with fly ash, and many expressed concerns for the future. It appears that the major regulatory concerns that affected fly ash supply in the early 2010s have been somewhat resolved by the 2015 ruling retaining the Bevill exemption. But, some of the consequences, combined with the effects of economic conditions, are that in some areas fly ash sources have changed (i.e. from Class F, which is considered better for ASR mitigation, to Class C) or are not as consistent (i.e. due to plants abilities to change to natural gas based on economics). Due to this, concrete may cost more and/or may need to be placed without the benefit of fly ash in the short term in certain areas. In the long term, fly ash supplies are predicted to remain constant or increase slightly, and current beneficial reuse is less than 50% of available supplies. At the same time, due to sustainability concerns and ASR, fly ash demand is anticipated to increase greatly.

To address some of these problems, recent NCHRP research has the potential of amending current specifications to allow more beneficial reuse of fly ash materials that were traditionally considered unusable. Alternative sources and new methods of using existing fly ash are also seeing increased focus.

Synthesizing and sharing the existing response to fly ash concerns, such as the survey performed as part of this effort, can provide alternatives to Agencies that are looking at addressing fly ash concerns in their States. A national effort is needed to address SCMs (supplementary cementitious materials) for the long term future of concrete structures and pavements.


II. Fly Ash Survey Summary (52 total Agency responses) A survey was sent to the AASHTO Subcommittee on Materials(SOM) List serve, the Federal Aviation Administration (FAA)’s Pavement Group and the Federal Department of Defense (U.S. Army Corp of Engineers). The survey had 52 respondents: 46 State DOTs, DC DOT, Illinois Tollway, Western Federal Lands(WFL), Ontario (MTO) and the FAA, and DOD(COE). The survey asked if the Agency had an issue with fly ash in the past 4 years, the class of fly ash that was the concern and what if anything the Agency was doing to address the issue. The survey shows that the concern with fly ash supply is not a minimal or regional issue. It also shows that some Agencies are responding with a combination of immediate changes and long term research to address the difficulties they are encountering. The complete survey results are included in Appendix D. The following provides some of the highlights of the survey:

Ø 100 Percent of the Agencies noted that fly ash was used by their Agency in structural concrete or concrete pavements.

Ø An estimated quantity of fly ash use was requested, but fly ash quantities are not something normally measured by Agencies, so most respondents (30) did not submit a quantity, but of the States that submitted quantities they varied from 150 tons/yr to 150,000 tons/year.

Ø The survey asked if fly ash was used for durability, ASR mitigation, cement replacement

or other. Each Agency could select more than one choice, and the percentages shown in Figure 1 show all the choices made. Specifically, cement replacement was noted by over 80% of the respondents (44 out of 52), with durability and ASR mitigation identified by 42 and 37 respondents, respectively. As can be seen, while fly ash is important to ASR, it is not considered as the only reason fly ash is identified as being used. Taken as a whole Agencies considered durability, ASR mitigation and cement replacement almost equally. In the ‘other’ category agencies also identified permeability, sulfate resistance, mass concrete, high temp resistance and sustainability as uses. The COE especially was concerned with fly ash for mass concrete.

Figure 1- DOT responses to primary uses (multiple choices allowed)

durabilty33%

ASRmitigation

29%

cementreplacement

35%

other3%

FLYASHUSES


Ø Over 80% (42 of 52) of the Agencies noted experiencing supply issues in the last 4 years

as shown in Figure 2. Of the 9 Agencies that noted they had not had an issue with fly ash in that timeframe, 6 of those did note that they had heard concerns from contractors or other industry. Two of the Agencies (Maine and Western Federal Lands(WFL)) that noted they had not had a fly ash issue also shared that they had a very low demand for fly ash. Both FAA and DOD/COE expressed widespread concern over fly ash issues.

Figure 2-Agencies noting fly ash issues over last 4 years

Ø Over 50% of the Agencies identified having an issue with fly ash were concerned with

Class F (22) fly ash, about 28% Both (12) and about 20% (8) identified Class C fly ash alone as noted in Figure 3. Between Class C and Class F fly ash, Class F is considered more effective in mitigating ASR (See Appendix C for a link to FHWA’s ‘Fly Ash Facts for Highway Engineers’ for more information related to the definition and difference between C and F ash). It appears from the map that the west coast and east coast either predominately use F ash or that they are having supply issues with F ash, while the midwestern and central states identified both C and F or C ash.


Figure 3- Type(s) of fly ash identified as an issue

Ø Location of fly ash sources and an Agencies lack of access to non-ASR susceptible

aggregate are both factors that can affect the supply and demand of different types of fly ash in an area. Illinois stated that only Class C is produced in their State, so that is what they primarily use. The need to transport fly ash based on demand can increase costs. New York noted they were adding foreign sources of fly ash. Wyoming noted they were looking at getting some fly ash from as far away as Louisiana, and although not in the survey results, Georgia has approved a fly ash source from India in response to supply issues.

Ø The issues noted with fly ash were mainly described as supply issues, sometimes identified as seasonally related. To a much lesser extent inconsistency in the fly ash material and erratic air content in the concrete due to fly ash was noted.

Ø Thirteen Agencies noted they have made recent changes to their specifications, but some

of those were noted as actually increasing the allowable fly ash replacement percentages.

Ø Some Agencies noted they have made it easier to switch fly ash sources on construction or have identified new sources of fly ash (AL, CO, FL, IL Tollway, MA, MO, PA, RI and TX) or are working towards ways to facilitate such changes (AL, TN). Some Agencies noted they are looking at alternatives to fly ash (FL, GA, NM, RI, WI, WFL, COE), including sponsoring research in this area. Slag was noted as an option that was being chosen by Contractors in a number of responses. The use of ternary mixes or blended cements were also noted.


Ø Forty-four Agencies also identified using fly ash in areas such as flowable fill, soil stabilization or grout.

Two particularly interesting areas to share were identified: Nebraska’s use of blended cements to control quality and quantity issues: “We no longer approve ash as a stand alone component for PCC. We test and approve the blended cements. Our current cement specification allows for cements to be blended with combinations of C-ash, F-ash, Slag, Clays.... We then test final blend of cement for chemical (CaO & SiO) to determine is enough mitigation properties exist (testing done on samples from the project). Same tests and 1567 (ASR) testing is done prior to get cement on Qualified Product List. All this allows the cement supplier to be creative and get several cement blends approved and since they are blended at terminal we get very consistent cement that can be tested as a final product at the project level.” And South Carolina’s interesting answer: “… our local Ready Mixed concrete association has lobbied our legislature and recent legislation requires the main power company to produce 900,000 tons/year of usable fly ash by 2019.”


III. Summary of policy changes and research activity happening nationally Agencies identified the need for increased flexibility and the need to be proactive in response to fly ash concerns. Many noted that they anticipated the use of SCMs (supplementary cementitious materials) to increase due to ASR concerns and desire for sustainability/durability. Therefore, a number of State DOTs have already started sponsoring research looking at alternatives to fly ash in the future.

Ø State DOTs are making it easier for contractors to change sources while a project is ongoing (State survey results)

Ø State DOTs are allowing for substitution of more materials for fly ash, such as slag/ ground granulated blast furnace slag (GGBF) (State survey results)

Ø State DOTs are starting to implement the recommendations related to ASR mitigation in PP65, leading to potential higher allowable percentages of fly ash in concrete (State survey results)

Ø Florida has ongoing research looking at new sources of pozzolanic materials (Florida Research-in-Progress BDV31-977-06) and a Contract for a Resource Evaluation study related to fly ash.

Ø Texas has recent research on alternatives to fly ash that found “SixoutoftheeightpozzolanstestedwerefoundtobeviablealternativesforClassFflyash.Theseincludedametakaolin,aperlite,apumice,acalcinedshale,avitricash,andazeolite.”, as shown in Table 6.1 below from the Texas Research report (FHWA/TX-14/0-6717-1)

Ø Texas also has these ongoing research projects:

o Project 5-6717-1 is a continuation to Project 0-6717-1, Evaluation of Alternate SCM’s which is evaluating materials such as blended SCM’s and reclaimed ponded fly ash as possible mitigation strategies for ASR. This project is set to terminate August 2017, so only preliminary data to report now.

o Project 0-5606, “Chemical Solutions for Durability Problems,” is a project that was initiated to provide durability solutions for when fly ash is no longer available or in limited supply. This project is evaluating chemical admixtures for effectiveness in mitigating ASR, Sulfate attack, and other durability issues


that the use of fly ash would typically solve. o Project 0-6656-1, “Further Validation of ASR Testing and Approach for

Formulating ASR Resistant Mix,” is a project evaluation for a new method for determining aggregate reactivity.


IV. Identified short and long term impact on the transportation industry It appears that the major regulatory concerns that affected fly ash supply in the early 2010s have been somewhat resolved by the 2015 ruling retaining the Bevill exemption. But, some of the consequences are that in some areas fly ash sources have changed (i.e. from Class F, which is considered better for ASR mitigation, to Class C) or are not as consistent (i.e. due to plants abilities to change to natural gas based on economics). Due to this, concrete may cost more and/or may need to be placed without the benefit of fly ash in the short term in certain areas. In the long term, fly ash supplies are predicted to remain constant or increase slightly, and current beneficial reuse is less than 50% of available supplies. At the same time, due to sustainability concerns and ASR, fly ash usage is anticipated to increase.

SHORT TERM Ø 80% of State DOTs identified recent supply issues (2012-2016) with fly ash (State

survey) Ø A recent Survey of the Production and Use of Coal Combustion Products (CCPs) found

that fly ash production (44 million tons) was down 13% but use (24.5 million tons) was up 6% in 2015 as compared to 2014.

Ø Texas is experiencing a situation where power plants that historically supply a Class F fly ash are switching coal sources and will soon be supplying a Class C fly ash. TxDOT’s primary mitigation strategy is the use of Class F fly ash, so any reduction of Class F fly ash is seen as a huge impact to their ASR mitigation strategy. The understanding is that these changes are a results of the new emission requirements.

Ø Until enough quantity of suitable alternative materials to fly ash are approved and available (i.e. slag cement or GGBF/slag isn’t always available or economical in all areas of many states), the cost of concrete and transportation projects, such as concrete paving projects, may be increased when there are fly ash shortages, and fly ash is used as a replacement for cement. (For example, in WV, they allow approximately a 16% replacement of cement with fly ash in their concrete paving mixes. If concrete pavement mixes could not get enough fly ash to pave the entire project, then a mix containing 100% cement would need to be used instead, and this would cause higher unit bid prices for concrete and additional cost to the project. Not enough slag cement would be available or economical as a replacement for cement to be able to pave the entire project instead of using fly ash as a replacement.)

Ø Until enough quantity of suitable alternative materials to fly ash are approved and available, concrete mixes may be placed with quality issues such as durability (i.e. permeability issues, ASR issues, additional heat of hydration, etc.).

Ø In June 2010, EPA proposed regulating CCPs as either solid waste under Subtitle D of the Resource Conservation and Recovery Act (RCRA) or as a hazardous waste under Subtitle C of RCRA.…This period of regulatory uncertainty had significant implications for CCP utilization.” (ACAA Key Findings Document, 2015)

Ø “The 2015 final rule regulating CCPs as nonhazardous and retaining the Bevill exemption for CCPs that are beneficially used restores certainty to markets.” (ACAA Key Findings Document, 2015)

Ø Fly ash variability is not new, a 2008 research report noted: “Fly ash, by the nature of its formation, can be highly variable. It is a byproduct of the production of electrical power.


From the viewpoint of the power companies that produce fly ash, quality of the ash is secondary to economical operation of the power plant. Thus, ash properties can be highly variable depending on the parent coal material, plant operation/combustion conditions, and collection methods.” (Texas Research report FHWA/TX-08/0-5207)

LONG TERM

Ø “CCP utilization is projected to increase from 51.6 million short tons in 2013 to 76.5 million short tons in 2033” (ARTBA report, 2015)

Ø “Fly ash, which represents the largest percentage of CCPs by tonnage, is expected to increase by about two percent over the next 20 years to 54.6 million short tons in 2033. As coal-fueled power plants shift to dry handling of CCPs to comply with regulations, the availability of useable fly ash is expected to increase.” (ARTBA report, 2015)

Ø “Fly ash utilization is forecast to increase 53 percent over the next 20 years, to 35.7 million short tons. Expanding use of fly ash in high volume applications, new concrete mixtures and future growth in the ready-mixed concrete market will drive increased utilization.” (ARTBA report, 2015)

Ø Fly ash production in 2033 is forecast to be between 38.9 and 82.9 million short tons (Figure 3-4, ARTBA report, 2015)


V. Review of emerging technologies, strategies and products RecentNCHRPresearchhasthepotentialofamendingcurrentspecificationstoallowmorebeneficialreuseofflyashmaterialsthatweretraditionallyconsideredunusable.Usingforeignsourcesofflyashandalternativemethodsofusingexistingflyashareseeingincreasedfocus.Someactionsandstrategiesthatmightbeappliedshort-termtoincreaseflyashavailabilitynextyear:

Ø SOM is reviewing recent NCHRP research that has proposed changes to the existing fly ash specifications to address the concern that “existing test methods for sampling and testing fly ash used in concrete do not adequately address the characterization of fly ash” and “Such inadequate characterization may lead to unwarranted restrictions on the use of suitable materials”. (NCHRP Report 749)

Ø Encourage States and Regions to start or continue a dialogue with the SCM industry (similar to California’s Task group) to identify potential local solutions that will fit their situation the best.

Ø “Although coal ash imports currently represent a negligible portion of U.S. supply, international supplies of CCPs that meet U.S. standards could be used…” (ARTBA, 2015). Some States are already allowing foreign sources (i.e. New York and Georgia) and this information and their experiences could actively be shared with other States. Of course, additional transportation costs are anticipated in the use of foreign fly ash.

Ø “Improved storage facilities would help regulate the supply of fly ash during times of lower power demand and routine shutdowns.” (ARTBA, 2015)

Othertechnologieswillneedmoreworkandverificationforthematerials,proceduresandregulatoryframeworkineachState

Ø “A “one size fits all” approach to concrete mixtures does not achieve the goal of maximizing long-term durability because the quality of local materials used to produce the concrete strongly influence mixture properties and performance.” (NCHRP 566)

Ø “Currently there are research and demonstration projects focused on reclaiming fly ash that has been stored in either wet impoundments or dry disposal units. This could have significant impacts on the supply of fly ash.”(ARTBA report, 2015)

Ø “The biggest concern for use of fly ash in concrete is the quantity and form of unburned carbon.”…” The coal ash industry responded to the challenge of high or variable amounts of unburned carbon with several technologies.” …“There are three techniques to remove carbon from fly ash: mechanical, electrostatic, and thermal.” (Hank Keiper,2011)

Ø High LOI (loss on ignition) values are a concern with some fly ashes and a method to address that is to treat the fly ash with a chemical surfactant so it will act and perform the same as materials at a lower LOI. This provides agencies an opportunity to expand their LOI limits, increasing fly ash supply for their projects. Ohio, Kentucky and New York DOT have specifications for evaluating these type of chemical passivation systems. These states and others allow LOIs exceeding their maximum limits if chemically treated.

Ø Although there may be suitable alternative materials for use instead of fly ash, the question of will they be economical and available in sufficient quantity to meet the needs of the transportation industry in all areas has not yet been answered.


VI. Potential future research needed Synthesizing the existing response to fly ash concerns, such as the survey performed as part of this effort, can provide alternatives to Agencies that are looking at addressing fly ash concerns in their State now. A national effort is needed to address alternative SCMs for the long term future of concrete structures and pavements. Short-term research or synthesized findings that would help by next construction season

Ø Share experiences of successful alternate sources such as these topics that were part of a recent FHWA Workshop (potentially develop into a webinar for States):

o Hank Keiper (SEFA Group mining old Class F Fly Ash land fill) – Alternate Source of Fly Ash for ASR Mitigation. “Mr. Keiper presented the SEFA Group’s thermal beneficiation process – which processes ponded or landfilled ash into Class F fly ash by using the heat from burning the residual carbon in the ash and then classifying the resulting fly ash for use as an SCM.”

o Larry Sutter (Michigan Tech Univ.) – Update on ACI ITG-10 on Alternative Cementitious Materials (ACMs). “ITG-10 seeks to start a conversation between implementers (such as State DOTs) and researchers about a roadmap to implementation that includes field experience, data, and materials science research.”

o Larry Kaiser (GCP Applied Technologies Metakaolin, Grace Constr. & Packaging) – ASR Mitigation/Metakaolin. “Mr. Kaiser presented on the use of Metakaolin in preventing and/or mitigating alkali silica reactivity (ASR) in concrete.”

o (Quotes taken from Workshop summary document, referenced in Appendix C) Ø Provide Subcommittee on Material Technical Section 3b Task Force resources to assist in

rewriting AASHTO specifications to address fly ash characterization Ø Share information with AASHTO SOM concrete Technical Sections on use of Class C

and Class F blended fly ashes (ASTM C1697) allowed now by Georgia, Florida, Alabama, Kentucky and Tennessee DOTs.

Ø Share FHWA’s Tech Brief on ‘SCMs: Best Practices for Concrete Pavements’ to provide potential alternatives to fly ash for Agencies to consider regionally (FHWA-HIF-16-001).

Long-term research needs which might be a topic for an NCHRP Synthesis and/or several targeted Research Needs Statements (RNS) that would require several years of research.

Ø Conduct round-robin testing of new test methods proposed under NCHRP Report 749 to develop more confidence in their ability to replace older, traditional tests.

Ø Look more at blending fly ashes. ASTM C1697 allows blended supplementary cementitious materials. Using a C & F blend helps concrete achieve fairly low permeability. C1697 requires blended sources meet the fly ash standard C618. Perhaps a Class F, that doesn’t quite meet C618, and a Class C ash blend would work fine.

Ø Look at the feasibility of utilizing other types of materials, such as ground, recycled glass as a pozzolanic material. How much is available? What is the cost?


APPENDICES

Appendix A. Myths/Truths on Fly Ash Issue Myth:

There are no fly ash supply issues, or they are confined to one location only.Truth:80% of State DOTs identified a fly ash issue, and this included States in the west coast to the east coast. Class F and Class C fly ashes were both reported as being a concern, with some States noting issues with both. FAA and the Corp of Engineers also reported experiencing fly ash shortages. Myth:

Supply issues mean we are running out of fly ash. Truth: Coal will continue to account for a significant percentage of U.S. electric generation during the next two decades. CCP production is forecast to increase by five (5) percent over the next twenty years, from 114.7 million tons in 2013 to 120.6 million tons in 2033. (ACAA, 2015) Myth:

Fly ash is much more different than it used to be. Truth: Fly ash has always been variable by its nature, but it is also true that it is changing. But “inadequate characterization” and the way we use fly ash also needs to change so we do not promote “inappropriate use of some materials or unwarranted restrictions on the use of suitable materials”. (NCHRP Report 749)

Myth:

The fly ash issues are over! Truth: In some areas fly ash sources have changed (i.e. from Class F, which is considered better for ASR mitigation, to Class C) or the supply will be not as consistent (i.e. due to plants abilities to change to natural gas easier based on economics). Due to this, concrete may cost more and/or may need to be placed without the benefit of fly ash in the short term in certain areas until changes are made.


Appendix B. Task Force Members

Member Affiliation/State Email Moe Jamshidi SOM Chair (Nebraska) [email protected] Thomas Adams American Coal Ash

Association [email protected]

Gina Ahlstrom FHWA [email protected] Sejal Barot Shekhar Murkute Vicki Stewart

Maryland [email protected] [email protected]

Lyndi Blackburn Drew Waldrop

Alabama [email protected]

Ben Franklin Headwaters Resources [email protected] Keith Hoffman California [email protected] Clint Hoops Idaho [email protected] Kim Kurtis Cole Spencer

Georgia Tech [email protected] [email protected]

Mike A. Mance West Virginia [email protected] Richard Meininger FHWA [email protected] Greg Mulder Todd Hanson

Iowa [email protected] [email protected]

Andy Naranjo Texas [email protected] Timothy Ruelke Florida [email protected] Jack Springer FHWA [email protected] Larry Sutter Michigan Technology

University [email protected]

Mick Syslo Nebraska [email protected] Craig Wallace Headwaters Resources [email protected] Jack Youtcheff FHWA [email protected] Evan Rothblatt AASHTO liaison [email protected] Katheryn Malusky AASHTO liaison [email protected] Georgene Geary AASHTO Consultant and

Note taker/report writer [email protected]


Appendix C. Referenced documents and research reports

Ø NCHRP 749 - Methods for Evaluating Fly Ash for Use in Highway ConcreteØ NCHRP 607- Specifications and Protocols for Acceptance Tests on Processing Additions

in Cement Manufacturing & Appendix A- Fly ashØ ACCA Key Findings 2015Ø Production and Use of Coal Combustion Products in the U.S. (ARTBA June 2015)Ø FHWA 4-6-16 (presentation by Thomas Adams of ACAA to FHWA)Ø Overview of TFHRC 3rd Bi-Annual Workshop on Emerging Developments Related to

Alkali-Aggregate-Reaction (AAR) and the Use of Alternative Cementitious Materials(ACMs) in Highway Infrastructure (2016 ACM-AAR Workshop Summary)

Ø Fly ash Issue Document 2016-05-27.docx (from California)Ø NCHRP 566- Guidelines for Concrete Mixtures Containing Supplementary Cementitious

Materials to Enhance Durability of Bridge DecksØ Links to TxDOT’s Alternate SCM project. The first link is the full report and the second

is a short summary:o http://library.ctr.utexas.edu/ctr-publications/0-6717-1.pdfo http://library.ctr.utexas.edu/ctr-publications/psr/0-6717-s.pdf

Ø Link to Fly Ash Facts for Highway Engineers: FHWA Report FHWA-IF-03-019 –http://www.fhwa.dot.gov/pavement/recycling/fach00.cfm

Ø Link to FHWA’s Towards Sustainable Pavement Systems: a Reference Documenthttp://www.fhwa.dot.gov/pavement/sustainability/ref_doc.cfm

Ø Link to FHWA’s ‘SCMs: Best Practice for Concrete Pavements’ Tech Briefhttp://www.fhwa.dot.gov/pavement/pub_details.cfm?id=977

ACI 232 Active Committee Document Links:Ø 232.3R-14: Report on High-Volume Fly Ash Concrete for Structural ApplicationsØ 232.2R-03: Use of Fly Ash in ConcreteØ 232.1R-12: Report on the Use of Raw or Processed Natural Pozzolans in Concrete (This

provides information on alternatives to fly ash.) The other major SCM material that might be used instead of / or blended with fly ash is Slag Cement (ACI Committee 233)

ACI 233 Active Committee Document Link:Ø 233R-03: Slag Cement in Concrete and MortarØ The Slag Cement Association Website provides some information also on use instead of

/ or blended with fly ash –http://www.slagcement.org/publications/InfoSheetIndex.aspx

Link to Kentucky Conference (Midwest Workshop on Current Issues in Ponded CCPs): http://www.worldofcoalash.org/ash/ Hank Keiper, P.E.. “Addressing Coal’s Negative Impact – Beneficial Use of Fly Ash.” The Virginia Engineer. (April 2011). Mid-Atlantic Area Manager for SEFA. http://vaeng.com/guestarticle/addressing-coal-s-negative-impact-beneficial-use-of-fly-ash Dropbox link for documents without links: https://www.dropbox.com/sh/n3ro4kqw089g0kc/AAClOfdhRsDzKn8BAr1zM9Q2a?dl=0

AGENCY

DoesyourState/organizationuseflyashinstructuralconcreteorconcretepavements?

Isflyashusedfor(checkalltheapply):durability

ASRmitigtion cementreplacement

Other: Estimatedtons/yrflyashused? HasyourState/Agency(orcontractors)hadanyflyashissues(mainlysupplyissuesbutalsoanyunusualquality/consistency)inthepast4years(2012-2016)forstructuralconcreteorpavements?

WeretheissuesrelatedtoClassC,ClassForBoth?

Couldyoubrieflydescribetheissueandwhatyoudidtoaddress(i.e.startedresearchtoidentifyalternatives)?

Haveyoumadeanyrecentchangestoyourspecificationsandoracceptanceprocesses/protocolsrelatedtoflyash?

Explain: Asaresultofanyoftheaboveinformation,areyoucontemplatingchangestoyourpoliciesregardingflyashuseinconcretemixtures?

Alabama Yes durability cementreplacement

Uncertain.Mixesallowupto30%percy

Yes Both Supplyissues,forbothclasses,butmainlyF

Yes Workedwithconcreteproducerswhenissuesarise.

IfYes,pleasedescribe:

Alaska Yes durability ASRmitigation

FAArequiresflyashasanASRmitigation--otherthanthatAlaskadoesnotusealotofflyashequalincosttocement.

Notsure No

Arizona Yes durability ASRmitigation

cementreplacement

No

Arkansas Yes ASRmitigation

cementreplacement

Nottracked. No

California Yes durability ASRmitigation

cementreplacement

20%cementreplacement.Unknowntotalvolume

Yes ClassF Caltransiscurrentlyinvolvedinastudywithindustrytoidentifyshortagesencounteredearlierintheyear,andattempttoidentifyfuturesimilarimpactsinthenextfiveyears

No No

Colorado Yes durability ASRmitigation

cementreplacement

Unknown-don'ttrack Yes ClassF Powerplantshuttingdownforrepair-allowedsupplierstoswapsourceswithoutprequalifyingmixes

No No

DC Yes ASRmitigation

cementreplacement

Don'tknow Yes Both Researchandchangeinmixdesign Yes Inprocessofchangingmixdesignrequirements

Yes

Florida Yes durability cementreplacement

Basedonanestimatedof24millioncubicyardsofconcreteconsumedinFDOTwork,(precast,prestressedandCIP)theclosestestimatethatIcancomeupwithis1,440,000tonsofClassFflyashwhichisprojectedtobeusedbytheendof2016.

Yes ClassF Localshortages-hadtotchangespecificationtoallowtheperformanceofsourcesubstitutionstobeverifiedontheprojectsduringproductionratherthanintheproducerslabpriortoproduction.Weareresearchingalternativestoflyash.

Yes Inordertopreventdelaystoprojects,wehaveallowedtheperformanceofmixeswithanalternatesourceofflyashtobeverifiedontheprojectratherthanattheproducerslabpriortothestartoftheproject.Thishasbeendoneonacasebycasebasis.


Georgia Yes durability ASRmitigation

cementreplacement

UseofflyashtodobetterthermalcontrolonMASSCONCRETE

Yes Both Wewereinformedbybothconcretecontractors(flyashasSCM)andasphaltcontractors(flyashasSMAfiller)thattheystruggledtosecurethesupplyofflyashfortheirprojects.ConcretecontractorsturnedtoslagastheirSCM,andasphaltcontractorsstartedtousemarbledustasSMAmineralfillers.Stateissponsoringresearchtoidentifyalternatives,suchasMetakaolin,anaturally-occuringpozzolan(ASTMC619ClassNPozzolan),inordertomeetthechallengeofflyashsupplyshortage.

No IfYes,pleasedescribe:

Idaho Yes durability ASRmitigation

cementreplacement

WehavenoapprovedsourcesofClassCashsoalloftheashweuseisClassF.WealsoallowtheuseofGGBFSandseethismaterialinlessthan20%ofourmixes.Theminimumreplacementrateforslagis50%.

Yes ClassF Powerplantwasshutdown.Allowedanewashwithoutmixdesigntesting.

No No

Illinois Yes ASRmitigation

cementreplacement

~70,000 Yes ClassC Erraticaircontents;strongsulphursmell;fewerandfewerplantsproducingflash;risingCaOcontentsinflyash(criticaltoIDOTsASRmitigationspec).

No Nochangestoaddressanyoftheabove.Ithinkalotoftheaboveissuesare"marketdriven";thatis,theissueofproducingaconsistentproductconsideringcoalsourceeconomicsandEPAregulationsisbeyondtheDOT'scontrolandismainlyaproblemfortheconcreteproducerand/orcontractor.Wewouldlikeamoreconsistent,betterperformingmaterial,butwhatpowerdowehavetogetit?Betterspecsmightnotmeanitwillbemade.


IllinoisTollway Yes durability ASRmitigation

cementreplacement

Yes ClassC Supplyissuesresultinsourcechangestoooftenduringprojects.

Yes Gaveallowanceforflyashestobemoreeasilysubstitutedbasedoncementandflyashchemicalcomposition.

No

Indiana Yes durability cementreplacement

Yes Both Primaryissueisavailabilityshortages.TodateIndianahasnotmadeanyadjustments.ContractorsarevoluntarilyconsideringGGBFS.

Yes ImplementingnewpavementspecificationthatincreasestherequirementforSCM's.

No

Iowa Yes durability cementreplacement

~100,000tons-20%replacementof4.5milSYpaving,plusstructuralconcrete

Yes ClassC 2016-Contractorswithstoragehavelimitedsupply.Hadareadymixsuppliercallaboutnothavingflyashforflowablemortarfill.

No No

Kansas Yes durability ASRmitigation

cementreplacement

lowerpermeability

Yes Both ClassCflyash-startedseeingmorecarbonintheash.Itmaybeaffectingtheentrainedair.Microairhasbeenhelpfultoaddress.ClassFflyash-startedseeinglessoftheashavailable.

No No

Kentucky Yes cementreplacement

15,000ton Yes ClassF StrengthActivity-removedsupplierfromapprovedlistSupplyshortageduringcertaintimesofyear.LOI-allowincreasewithpretreatmentofashRecentissuewithammonia-isolatedanddeterminednotaperformanceissue

No No

Maine Yes ASRmitigation

175T No

Maryland Yes durability ASRmitigation

cementreplacement

1329tons(2015)and582tons(JanuarytoJune2016)

Yes ClassF WehadissueswithClassFsupply.Webroughtotherplantsinfortestingandapprovalasadditionalresources.

No No

Appendix D. Agency Fly Ash Survey Results

15

AGENCY









Massachusetts Yes durability ASRmitigation

25,000-30,000Tons/year Yes ClassF haveinvestigatedothermeans&methodsthatcanmitigatedtheflyashshortage


Michigan Yes durability ASRmitigation

cementreplacement

Yes Both AircontentwasimplementedasPWLpayfactor.theinconsistencyofusingflyashvsconsistencypromptedpavingcontractorstouseslagcementexclusively.


Minnesota Yes durability ASRmitigation

cementreplacement

ConcretePaving40-70Ktonsperyearforthepast6yrsAllow33%flyashinpavements,30%structuresHadallowed15%flyashingeneralconcrete/flatworkuntil2016,nowallow25-30%

Yes Both Manyissuesoversupply/delivery/flooding/railroadsin2013-2015.In2016,concernsweremorerelated(to)materialshortage,hasbeenminimalsofar.

Yes MNDOTdidamajorreviewofASRdataandchemicalflyashdataandmadeadjustmentsaccordingtolocalexperienceandAASHTOPP65.(Nochangesplanned)-Changeshavealreadybeenmade-wehaveallowedternarymixestoutilizeslagwithflyash,modifiedw/cspecifications/incentivesforpavementtoaddressesincreaseduseofslag/ClassCflyash.

No

Mississippi Yes durability cementreplacement

Sulfateresistance

No

Missouri Yes durability cementreplacement

Reducemixturecost

15000 Yes ClassC 1)Experiencingsupplyissueresultinginconcretesuppliershavingtochangesources.MoDOThasrelax(ed)requirementsonsubmittingnewmix(es).2)Startingtoseeanincreaseinairvariability

Yes Notrequiringanewmix.WearetrackingflyashsourcechangeinremarksfieldinSiteManager,startedthisyear.(Nochangescontemplated)Wewouldliketocontinuetouse.Believeflyashimprovesthequalityofconcretewhilereducingcostandrecyclingmaterial.

No

Montana Yes durability cementreplacement

unk Yes ClassC OurlargestsupplierofClassCFlyAshclosed.

No No

Nebraska Yes durability ASRmitigation

TypeFforPCCwasabout39,689Tonsin2015TypeCforsoils...wasabout20,516Tonsin2015

Yes ClassF Ourcementsareblendedattheterminals(notbycontractorsontheprojects)socementsuppliershavehadissueswithlongtermreliablesources.Sofartheyhavebeenabletoswitchsuppliersandstillblendinwinterseasonstomakeenoughcementforourfollowingpavingseason.

Yes WenolongerapproveashasastandalonecomponentforPCC.Wetestandapprovetheblendedcements.OurcurrentcementspecificationallowsforcementstobeblendedwithcombinationsofC-ash,F-ash,Slag,Clays....Wethentestfinalblendofcementforchemical(CaO&SiO)todetermineisenoughmitigationpropertiesexist(testingdoneonsamplesfromtheproject).Sametestsand1567(ASR)testingisdonepriortogetcementonQualifiedProductList.Allthisallowsthecementsuppliertobecreativeandgetseveralcementblendsapprovedandsincetheyareblendedatterminalwegetveryconsistentcementthatcanbetestedasafinalproductattheprojectlevel.


Nevada Yes durability ASRmitigation

cementreplacement

20%minimuminallconcreteusedonNDOTprojects

Yes ClassF FlyAshshortage.WealsoallownaturalpozzolanasareplacementforflyashortheuseofIPCement./supplyandunconfirmedvariabilityaffectingstrengthgainofpavement

No Itwoulddependonyourdefinitionofrecent.

No

NewHampshire Yes ASRmitigation

Yes ClassF Shortageswereduetopowerplantconversiontonaturalgas,basedonlowercosttocoal.Flyashwassubstitutedwithslagwhensupplywasunavailable.

No No

NewJersey Yes durability ASRmitigation

cementreplacement

pozzaloan notsure Yes ClassF ShortageofflyashforPCCadmixtureduetoscheduledmaintenanceatpowerplants(ie.Somerset,MA),shuttingdownofpowerplantduringjob(Norfolk,VA)andlackofcoalburningatsomepowerplants.WeapprovedadditionalplantsinGAandIbelieve,NC.

No No

NewMexico Yes durability ASRmitigation

cementreplacement

30000 Yes ClassF TherewasaClassFFlyAshShortage.WebegantoresearchandtestothercementitiousmaterialsinourconcretemixdesignstoseeifthereareotheralternativesthatmitigateASRwhilestillprovidingadurablequalityconcrete.


NewYork Yes durability ASRmitigation

18,000tons/yr Yes ClassF supplyissues-newsourcesfromforeigncountrieshavebeenestablished.qualityissues-workedwithsupplierstoprocess/treatF-ashtoreducecarboncontentand/orcarbonfixationofsomesort


NorthCarolina Yes durability ASRmitigation

cementreplacement

Yes Supplyissues-Wehavethisissueseasonallywhenenergydemandislowandthepowercompanyisnotburningasmuchcoal.Wetypicallyhavearushonrequeststoapprovestraightcementmixesduringthistimeframeandproducerssavethereflyashforwhenitisrequired.

No Werecentlyincreasedtheamountofflyashallowedinconcretemixesbuthavenotseenmany,ifany,producerssubmitnewmixdesigns.(Allowupto30%flyashinmixas1:1ratiotocement)(Contemplatingchanges)No,butourlocalReadyMixedconcreteassociationhaslobbiedourlegislatureandrecentlegislationrequiresthemainpowercompanytoproduce900,000tons/yearofusableflyashby2019.

No

AGENCY









NorthDakota Yes durability ASRmitigation

cementreplacement

Yes ClassF Supplyissuesandlookingatotherashsupplies.

Yes Allowablealkalisfrom1.5to2.0. No

Ohio Yes durability cementreplacement

No

Oklahoma Yes cementreplacement

110,000tons Yes ClassC Contractorshavecomplainedaboutalackofsupplyanddon'talwaysuseashbecauseofsupply.Wehadapavingprojectweretheflyashhadtomuch'Trona'initandthemateralsetupinthedumpbeds.

No No

Ontario,Canada Yes cementreplacement

FlyashisusedinfrequentlyandinverysmallnumberofOntarioMinistryofTransportationcontracts.Slagisavailablelocallyandisthepreferredsupplementarycementingmaterial.

Yes Both Flyashandslagreducesaltscalingresistanceandaremoresusceptibletopoorconstructionpractices-thereforereplacementlimits(are)inplace.Ontariolimitsflyashreplacementto10%bymassoftotalcementingmaterials.AtthecurrentMTOreplacementlevels(10%flyashand25%slag)scalinginthefieldisaboutthesameaswithportlandcementconcrete.(Note:Flyashreplacementlevelupto25%allowedinhighperformanceconcrete-again,notusedmuch).

No No

Oregon Yes durability ASRmitigation

cementreplacement

Flyashisusedinmostofourconcrete.Idon'thaveanestimateoftons/yr.

Yes Both Allowedtheuseofslagasadirectreplacementofflyashinourmixes

No

Pennsylvania Yes durability ASRmitigation

cementreplacement

150,000tons Yes ClassC SomeClassC'swouldn'tpassASTMC441andarenotapprovedforASRmitigation.Hugeissueswithavailability.

Yes WeareintheprocessofimplementingAASHTOPP-65whichwillrequiremoreprescriptivelevelsofSCM'sincludingflyash.


RhodeIsland Yes durability ASRmitigation

cementreplacement

Fewtonsbasicallyjustinsomeprecastoperations.

Yes ClassF Drivenbyindustry,movedtoslagwhenflyashshortagesoccurred.

Yes Ononeprojectweallowedatentativeapprovalbaseduponthesupplybeingapprovedinanotherstate.

No

SouthCarolina Yes durability cementreplacement

Willhavetogetbacktoyouontonnage.

No

SouthDakota Yes durability ASRmitigation

Yes ClassF Supply&specificgravityuniformityfailures

No

Tennessee Yes durability cementreplacement

Wehavenowayofdeterminingthisdata.

Yes ClassF ManyofourFashsourceswereexperiencingoutageseachfallandthereforeleavingreadymixproducerswithoutflyash.

Yes Wehavewentfroma20%replacementrateforF-ashto25%maximumreplacementrate.


Texas Yes durability ASRmitigation

cementreplacement

somesoilstabilization

150to200tons/yr Yes Both PowerPlantsinTexastypicallyhaveroutinemaintenanceshutdownsduringthespringmonths(March-May),atwhichtimeonlysmallamountofflyashisavailable.Ifmultipleplantsshutdownatthesametime,wetendtoseeprolongsupplyissues.Wehavehadthisissuefortheseveralyearsnow.TxDOThasinitiatedresearchonalternativeSCM'sandtheuseofadmixturesfordurability.

Yes TxDOTnowallowsthecontractortoperformtrialbatchtestinginconjunctionwithconcretepourstoavoiddelaysduetowaitingfortrialbatchresults.

No

Utah Yes durability ASRmitigation

cementreplacement

20%replacementinallmixdesigns

No

Vermont Yes durability ASRmitigation

cementreplacement

330+tons Yes ClassF Typicallyhavebeenshortageofsupplyorplantbreakdowns.Usualsolutionistolookforalternativesourcesofflyash.Someproducershaveswitchedtoslagtoavoidthisandfortheconsistencyoftheproduct

No No

Virginia Yes durability ASRmitigation

cementreplacement

VDOTdoesn'ttrackthisinformation

Yes ClassF ourcurrentspecificationsallowalternatives,suchasslag,silicafume,andmetakaolin.WehavemetwithReadyMixSuppliersandFlyAshsupplierstodiscusstheirconcerns.Limitationsonsupplyappeartobeisolatedtosmallerconcreteproducerswithlowerhistoricalflyashdemands.

No No

WashingtonStateYes ASRmitigation

RequiredbyFHWAinitially

Don'tknow Yes Both Allowedgroundgranulatedblastfurnaceslagtobeusedinlieuofflyash.

No No

WestVirginia Yes durability cementreplacement

massconcrete Itwouldbeverydifficulttoestimatethetonsusedperyear.However,allofofconcretepavementcontainsflyash,andagoodportionofourstructuralconcretecontainsflyash.

Yes ClassF Supplyissues.Sometimes,powerplantswereunabletosupplyenoughflyashtoready-mixsuppliers.Wedevelopedaprocedurethatallowedready-mixsupplierstosubstituteanalternatesourceofflyash(orsubstitutetheflyashwithcement)intheirmixdesigns.

Yes Wedevelopedaprocedurethatallowedready-mixsupplierstosubstituteanalternatesourceofflyash(orsubstitutetheflyashwithcement)intheirmix

No

WesternFederalLandsYes ASRmitigation

cementreplacement

300tons No No IfYes,pleasedescribe:

AGENCY









Wisconsin Yes durability cementreplacement

sustainability 70,000tons Yes ClassC Therewassometimesashortageofavailablemateriallateintheconstructionseason


Wyoming Yes durability ASRmitigation

cementreplacement

MainlyASRmitigationforstructuralconcreteanddurabilityforinterstatepavements

?Donottrackmaybeupto2500ton

Yes ClassF workedwithsuppliersforalternativesourcesforASRmitigatingClassFashes.ForWyoming,lookingatsourcesinLouisiana,TexasandFourCornersarea.

No No

FAA Yes durability ASRmitigation

cementreplacement

Yes ClassF TherehasbeenagrowingconcernthatsupplyofFashisdwindling(longtermissue-whichwearestartingresearcheffortsforalternativematerials);andacouplefewprojectsinthepastyearhavebeeninformedthatflyashmaychangeduringtheprojectrelativetoquality/constituents(thisistheshorttermissueanditissignificantsincewehavenotolerancetoallowASRtooccuronairfieldpavement-thereforechangeofFashduringaprojectcannotbetolerated).

No Lastupdatewasin2014andwewillbereviewingthisissueforourupdatein2017.

No

DOD/COE Yes durability ASRmitigation

cementreplacement

hightempresistant,massconcrete,otherspecialtyapplications

unsurebutwouldguessinmultimillionsoftons/yr

Yes Both wehavemanysupplyissuesacrosstheworldwithflyashes.OutsideoftheUS,thingsareevenworse.Butdomestically,wehaveissuessourcingFashinmanyareas.InthosecaseswesometimeshavetoreformulateforCashwhichisnotdesiredandnotallowedinmanyofourspecifications.Cashesalsohavemuchmorevariabilitywhichmakesthemmoredifficulttospecifyubiquitously.BlendedashesarealsochallengingparticularlywhenblendedtobarelymeettherequirementsofanFashandsothesematerialexhibitsomeofthedisadvantagesofCashes.Wehavealsobeenhavingissueswithadditivestoashesforemissionsreductionsasthisisnegativelyinteractingwithairentrainingadmixtures.ThemainproblemisthatLOIisnolongeragoodindicatorofperformance.

Yes Insomecaseswehavedevelopedcustomspecsorperformedtestingtoallowmarginalmaterialsonprojectswhentherewasnooption.We’realsodevelopingsomenewtestmethodsbutthesehaveyettobeincorporatedintospecifications.OurDistrictengineersfrequentlyrequestinformationonpotentiallyusingnaturalpozzolans,silicafumes,orotherproductsinlieuofflyashduetoitsproblems.Theseareallallowedforinourspecificationsbuttheyarenotusedasfrequentlyandsomanypractitionersarenotfamiliarwiththeiruse…oratleastnotasmuchsoaswithflyash.

Yes

AGENCYAlabama

Alaska

Arizona

Arkansas

California

Colorado

DC

Florida

Georgia

Idaho

Illinois

IllinoisTollway

Indiana

Iowa

Kansas

Kentucky

Maine

Maryland

Explain: Haveyouheardofanyissues/concernsfromothers(i.e.consultants,otherindustry)relatedtoflyash?

Explain: IsflyashcurrentlyusedforothertypesofconstructionbyyourStateorAgency,suchasflowablefill,grout,mortar,stabilizedsoil,stabilizedbaselayers,roller-compactedconcrete,FullDepthReclamation(FDR)and/orembankment?

Explain:

Consideringspecchangestoallowswitchingoutsourcesmoreeasily.

Yes Sameconcernswesee. Yes Whenweuseflowablefillitisusedforsinkholerepair,itsalwaysaconcernforlargequantity.Forpipefilling,notasmuch.

No Pleasenote,Idonotheareveryproblemrelatedtomaterialperformance......especiallyiftheproblemwasresolvedandtheproductwasinconformancetothespecifications.

Yes ClassFflyash

Yes ShortageinNewMexicoduetoEPArestrictionsoncoalfiredpowerplantswhichsupplytheirmaterialssuppliers(NewMexicoDOT).

No

Yes Someconcernaboutavailability. Yes Flowablefill

Yes Aspreviouslymentioned,industryandCaltranshaveestablishedateamtoinvestigatetheissue.TheRockProductCommitteehasaskedthatthisissuebeinvestigatedtoidentifyandmitigatefuturepossibleshortages.Industryisakeystakeholderonthisteam.

Yes Generallyrequiredforpavementandstructuralconcrete.Forspecializedusesitwoulddepend.

Yes Both.=offspecashusedfornonconcreteproducts-flow,soilstabilization,etc.

No No

Weareresearchingalternativestoflyash.WehavealsocontractedtheBalmoralGrouptoresearchthefuturesupplyandcostsofflyashinFlorida.

Yes Generalcommentsandconcernsfromindustryrelatedtooverallreductioninproductionasaresultofotherfuelsuseforpowerproductionandlocalshortagestoproductoutagesandmaintenance.

Yes Whileallowedintheseotherapplications,itsprimaryuseinpracticeisourstructuralconcretes.

Wearecontemplatingtoallowotheralternativesthanflyashinbothconcreteandasphalt.

Yes PleaseseeanswertoQuestions7. No Flyashwasusedonmajorembankmentprojectsinthepast(justtogetridofitbyenergycompany),butitwon'thappenagainduetothepermanentshortageofflyashsupplyinthefuture.Ifyoudonotburncoalatapowerplantanymore,youwon'tgetflyash!

Yes Severalsourcesofashwillnolongerbeavailableinapprox.10years.

No

Tryingtodosometestingtore-evaluateourCaOlimit(26.5%)formitigatingASR;wouldalsolikebetterinfotocharacterizeflyashforASR/aircontentimpacts.

Yes SincemostflyashesproducedinILareClassC,I'ldsaythat'swhatendsupinmostapplications.

Yes ClassCforSoilstabilization.Nosupplyissues

Yes Flowablefill(bothF&C)

No Yes ClassC.Lookingatchangingsomeflowablefillapplicationstofoamedconcrete.

Yes PrimarilyfromReadyMixSuppliersandContractorsconcerningtheavailabilityoftheashandthepresumedaffectontheentrainedair.

Yes PredominantlyClassCAsh.Samesupplyissuesasstatedpreviously.

Yes Rratio(resistancefactor)forCash. Yes Flowablefill-ForCash-supplyissueduringcertaintimesofyear.

No No

No Yes Ifsupplyisdown,flyashisreservedforconcretestructuralproductsinsteadofflowablefill,grout,etc.

AGENCYMassachusetts

Michigan

Minnesota

Mississippi

Missouri

Montana

Nebraska

Nevada

NewHampshire

NewJersey

NewMexico

NewYork

NorthCarolina



Explain:

Atonepointinthefuturewemayneedtochangeflyashpolicies.WehavealongtermASRprogramongoingthatmayhelpinreducingourminimumflyashmitigationsforASR.

Yes Industryhasalmostonayearlybasistalkedaboutflyashshortageissues.WehavemoreconcreteproducersusingslagtomitigateASR.Ithasbeenverydifficultthelast5yearstogetanunbiasedandconsistentresponsetowhyflyashissoshortinsupplyatagivenseason.Wealsothinkthatitismorecostrelatedthantruesupplyissue.

Yes FlowableFillcurrentlyusestypeClassF.Wearecurrentlytalkingwithindustryonrevisingflowablefillspecandtheuse,amount&typeofflyashisincludedinspecdiscussion.

Researchisneededtogetourarmsaroundtheflyashqualityandtocraftspecstoprohibitpoorqualityash.

Yes Erraticaircontent.OveralleffectivenessofClassCashtomitigateASRasa"true"pozzolan.

Yes Flyashmanybeusedonoccasionasflowablefillcomponent.

Yes Countiesuseforsoilstabilization.CellularconcretegroutusesClassC,leanmixbackfillMNDOTallowsinsoilstabilization,stabilizedbaselayers,FDR&embankment,however,littleornoflyashavailableisactuallypermittedtobeused,socementisused.MinnesotahasinterestinknowingiflandfilledflyashcanbeobtainedandtreatedforfutureuseinconcreteandprovidelongtermdurabilityandASRmitigation.

Yes Problemsachievingdesiredaircontentattributedtonewmanufacturingprocesses.

Yes ClassCandF.TherehavenotbeenanyshortagesforDOTworkspecificallybuttalkfromindustryseemstoindicatethenumberofsuppliersisgettingsmaller.

Yes Hearingaboutairissue(i.e.variability)fromMoDOTconstructionpersonnel.

Yes ClassC,habeensomesupplyissues.

Yes InconsistentClassFFlyash. Yes CementTreatedBase

Continuetoworkwithourcementsuppliersondevelopingmoreblendsofcements.

Yes Asstatedabove,ourcementindustryiswhocomestouswiththesupplyconcerns.

Yes TypeC,whichwenormallydonothaveamajorsupplyissueunlessinaremotearea.

Yes Supplyshortage. Yes ClassF.Yes,supplyshortage.

No No

Yes OthersateDOT'sandindustry. Yes Geothechapplicationssuchasflowablefill.IwouldhavetocheckwithGeotechnicalBureautobesure.

WearelookingatourtestingresultsandrevisingourstatespecifcationstoallowtheuseofClassNPozzolans.

No Yes ClassFlyAshiscurrentlyallowedinflowablefill,mortarandgrout.

WealreadyallowuseofslagasanalternativetoF-ashinsomeinstancesbutlimitpozzolanuseto20%max.Newspecificationswillallowgreateruseofpozzolans,includingslagatcontentsgreaterthan20%forapplicationswherescalingandf/tarenotaconcern.developingperformancebasedspecstoputonusoncontractorsrelativetoPCCdurabilitycharacteristics(includingASR,scaling,andf/t)

Yes availability/shortages,someissueswithcontaminationand/orqualityimpactingabilitytoachieveaircontent.

Yes ClassF,withsamesupplyissuessinceit'sthesameproducersbatchingconcreteaswellasflowablefills

Yes ClassF

AGENCYNorthDakota

Ohio

Oklahoma

Ontario,Canada

Oregon

Pennsylvania

RhodeIsland

SouthCarolina

SouthDakota

Tennessee

Texas

Utah

Vermont

Virginia

WashingtonState

WestVirginia

WesternFederalLands



Explain:

Yes IfflyashnotavailablehowwillwemitigateASR.

Yes ClassF

Yes Contractorshaveexpressedconcernsbutnoprojectshaveactuallyhadissues/delaysetc.

Yes Both(FandC)havebeenused,nosupplyissues.Onlyforflowablefillinthelistabove.

Yes Justthecomplaintsaboutsupply.Wecan'tClassFashinourStateandhaven'tbeenabletoforyears.

Yes ClassCashisusedinCLSM,groutandstabilizedsoil.

No Yes Bothclassesareallowedbuthaveneverbeenusedextensively.

Yes Withthecoalfiredpowerplantslosingfavor,thesupplyofflyashisbecomingaconcern.Wewillcontinuetoallowslagasareplacementtoflyash.

Yes WeusebothClassFandC.Ourspecificationsallowthesuppliertouseflyashinourconcrete.Mostoftheconcreteforalltheitemslistedabovecananddocontainflyash.Ourspecificationsaresemiperformancebasedandassuchweseesupplementarycementitiousmaterialsusedinmostofourmixdesigns.

Justthespecchangereferencedabove.

Yes Availabilitybeingthebiggestissue. Yes canbeusedforsoilstabilizationandFDR.Notrequiredforflowablefill.

Yes Justthatthenortheastsupplyislessened.

Yes Flowablefillonaminimalbasis(ClassF).

No Yes FlowableFill,Rollercompactedconcrete,grout(limited)-ClassF

No Yes MostlyF,butsomeCusedinpavement,structures

Inthenearfuture,wewillbeperformingaroundrobinflyashstudywithmultipleproducerstodetermineiftherearenomajorperformancechangesbasedoffsourcematerial.Intheeventanoutageoccurs,theproducerwillbeabletoswitchtoanyotherashproducerthatwasapartoftheroundrobinstudywithouthavingtodevelopnewtrialbatchesformixdesigns.Thisisassumingthatallflyashproducersapartofthestudymeetalltolerancesandpredeterminedspecifications.

Yes FlowableFill,grout,FDR,RCC(BothF&Cash)

No Yes Somesoilstabilization,butprimaryusageisinconcrete.

Yes Supplyissues No

Yes instabilityofsupplyandvariablenessoftheproduct.

Yes WeonlyallowclassF.Sameavailabilityissueascastinplaceconcrete.

Yes ReadyMixConcreteProducershavecommunicatedtheirperspectiveonthesupplylimitationoverthelastfewyears.

No

Yes Supplyconcernsfromready-mixproducers.

Yes ClassF.Yes,wehavehadthesamesupplyissuesfortheseusesaswehavehadforpavementandstructuralconcrete.

No Yes Flyashisusedinflowablefill.

WeareevaluatingconcretedurabilityusingsomenewerlocalClassFsources.

Yes Contractorshavebeenconcernedaboutflyashavailabilitybecauseitaffectstheireconomics.

Yes Flyashisalsousedforflowablefill,andstabilizedbaseorsoil.However,theflyashusedforthesepurposesistypicallyoff-specashwhichwouldnotbeeligibleforuseinconcreteasacementreplacement.

AGENCYWisconsin

Wyoming

FAA

DOD/COE



Explain:

Consideringallowingotheralternativematerialssuchasclassnpozzolans.

No Yes both

Yes supply,concreteaircontentissues,futurecompositionafterCO2reductionmeasuresareimplemented

Yes (bothFandC)inflowablefill,grout,stabalizedsoil-nosupplyissues

Yes AsstatedinQuestion7above. Yes Yesbutsomewhatminor.Canbeusedforsoilstabilizing,stabilizedbaselayers,andFDR.ThesecouldbeCorF,dependingonneed,butpredominatelywouldbeC.

Flyashwillstillbeallowedfortheforeseeablefuture.Ourmainchangeswilllikelybetoopenupforuseofotherpozzolansandprovidingbetterguidanceontheirpotentialuse.WealsoplantointegratesomenoveltestmethodswhichcanbetterrelatepropertiesoftheashtoitsperformanceinconcretethansimplemeasureslikeLOI.ThisisacommonproblemacrosstheFederalGovernmentandforourDoDfacilitiesaroundtheworld.Itisanurgentproblemwhichweneedtoaddressparticularlyforareaswherethereisnoflyashwhichcanbeusedand,forexample,weneedtomitigateASR.Therearelimitedoptionstodothisparticularlyinremoteareaswhichbecomesverychallenging.

Yes Weuseflyashforalldifferentkindsofmaterialasyouhavelistedabove.Theissuesarereducedfornon-structuralmaterialslikeflowablefillsorstabilization.Therearestillshortagesinsomeareasbuttherearenotassignificantofconcernsinusingmarginalmaterialsfortheseapplications.