REPORT OF THEVIRGINIA DEPARTMENT OF TRANSPORTATIONIN RESPONSE TO SENATE BILL 469 (1992) ON

The Use of Recycled Materialsin Highway Construction

TO THE GOVERNOR ANDTHE GENERAL ASSEMBLY OF VIRGINIA

SENATE DOCUMENT NO. 53

COMMONWEALTH OF VIRGINIARICHMOND1994

TABLE OF CONTENTS

NO.

PREFACE ~ ~ ~ ..

EXEGUTIVE SUMMARy ~ ..

INTRODUCTION ~ ..

PURPOSE ..

SCOPE ~ .. ~ ~ ~ ..

CONCLUS IONS ~ ~ ..

RECOMMENDATIONS ~ ~ ..

APPENDIX I _ ..

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APPENDIX I I . 14

· PREFACE

The Virginia Department of Transportation (VDOT) underthe direction. of Ray D. Pethtel, Commonwealth TransportationCommissioner, was directed by the 1992 General Assemblythrough Senate Bill 469 to create a Committee to study theuse of waste glass and other recycled waste materials inhighway construction and make recommendations to VDOT onmethods of using these recycled materials. VDOT was todevelop specifications to use glass and other materials basedon these recommendations.

The Committee was also to develop guidelines for a fiveyear plan to encourage the use of recycled materia~s.

The Committee was to be composed of at least one memberfrom each of the following organizations:

Va. Department of TransportationVa. Road & Transportation Builders Assn.Va. Aggregate Assn.Va. Asphalt Assn.Va. Waste IndustriesVa. Dept. of Waste ManagementVirginians for Recycling, Inc.Local Government Organizations

A report of this effort was to be made to the 1994General Assembly.

The Committee looked into the use of glass and othermaterials in the following categories:

1. Glass2. Tires3. Plastics4. Yard Waste/Wood ~aste, Concrete & Paper5. Aggregate Fines6. Roofing Materials7. Bituminous Concrete

Recommendations were made for use of glass, tires,plastics, wood, concrete, paper and bituminous concrete.

VDOT has developed specifications in each of thecategories.

A plan was proposed by the Committee to encourage theuse of recycled materials. This plan consists of actions to

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allow continuing efforts to identify, experiment with andwrite specifications for waste materials. It also providesfor an educational process to increase the level of awarenessof everybody involved in the beneficial use of recycled wastematerials in highway construction. Many new processes andproducts are being developed using recyclable materials andVDOT has in place a New Products Committee to address thepossible use of these products.

It is the intent of the Committee to remain in plaGe forthe next five years to provide a contact point for thoseinterested in recycling. This Committee can also serve toencourage the use of recycled products that have proven valuein highway construction.

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EXECUTIVE SUMMARY

This report was prepared for the Recycled Materials inHighway Construction Advisory Committee by W. L. Hayden,state Materials Engineer for the virginia Department ofTransportation (VDOT), in response to Senate Bill 469 whichrequested VDOT to establish a committee to review and preparemethods to allow and encourage recycled products in highwayconstruction.

The Committee reviewed many products and waste materialsthat are being reprocessed, or have a potential for beingreprocessed, for use in highway construction. The final­action of the Committee was to recommend that the VDOTprepare specifications for recycled products in the followingareas:

-Recycled glass-Recycled tire rubber-Recycled plastics·Recycled wood and paper-Recycled concrete-Recycled asphalt pavements

The Committee reviewed the availability of various wastematerials and processes that have been developed beforerecommending these areas of use and determined that theprocesses exist and enough material is available to makespecifications feasible. The Committee recommended thatspecifications be developed and introduced in such a way asto allow the recycled products to be competitively bid withother products and processes. VDOT conducted a literaturereview, tried experimental projects and developedspecifications to accomplish the Committee's recommendationsin each of the areas. -

The Committee also recommended that the legislaturedirect the Committee to remain standing for a period of 5years to serve as a reviewer of new recycled processes andrecycled products in order that the industry, wastecollection agencies and others having an interest in findingnew markets for recycled products might have someone tocontact. It is believed that this Committee could serve as amechanism to investigate the potential for new recycledhighway products that are being proposed to legislativecommittees.

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INTRODUCTION

Senate Bill 469 (see Appendix I) directed the virginiaDepartment of Transportation to create a Recycled Materialsin Highway Construction Advisory Committee to makerecommendations to the VDOT regarding the use of recycledmaterials in highway construction. The Committee wascomposed of the following:

Members of Committee

Walton L. Hayden

Earl Robb

Bill Maupin

Bill RichardsTom CarrollRichard SchreckPaul GilbertAllan LassiterPaul HughesScott St. Clair

virginia Department ofTransportation-(Materials Div.)

Virginia Department ofTransportation '(Envi~onmental Division)

Virginia Department ofTransportation- (ResearchCouncil)

Va. Road & Transp. Builders Assn.Va. Aggregate AssociationVa. Asphalt AssociationVa. waste IndustriesVa. Dept. of waste ManagementVirginians for Recycling, Inc.Fairfax Dir. of Maint. & Constr.

PURPOSE

The,purpose of this Committee was to identify wasteproducts that can be recycled to become useful highwayconstruction materials'and recommend specifications to allowthe use of these waste materials. -

SCOPE

Because of the wide variety of materials that couldpossibly be used, the Committee's first effort was to enlistthe aid of the Virginia Department of Transportation'sResearch Council to conduct a literature review to determinewhich waste products are presently being used by other statesor agencies ..

Based on this review, the Committee decided to list thewaste materials that had the most potential for use in sevencategories as follows:

1. Glass2. Tires3. Plastics4. Yard WastejWood Waste,

Concrete, Old Newspaper4

5. Aggregate Fines6. Roofing Materials7. Bituminous Concrete

GLASS

Recycled glass has been used in several places aroundthe country~ The Committee made a concerted effort to findout how much glass is available for use in virginia. VDOT'sResearch Council produced a technical assistance report onthe use of glass in highway construction (see Appendix II).

The literature review identified that there were 140,000tons of waste glass generated in virginia annually. Of thatabout 15,000 to 40,000 tons were not presently beingrecycled. Some localities classify glass to remove therecyclable glass (clear waste glass and some specific typebottles) and then waste or landfill the broken and smallpieces (under 2"). This colored, small, and broken glasscould be made available for highway construction ifspecifications allow its use. The Committee identified twoareas of possible use, in asphalt pavements and in highwayembankments.

Inasmuch as asphalt concrete pavements are a verycritical construction item and research has shown thatasphalt pavement containing glass has durability problems, itwas decided to consider only limited use of glass in asphaltpavements.

The use of glass in embankments did not pose the sameproblems and the amount of waste glass available (15,000 to40,000 tons) could easily be used in embankment construction.The cost may be much higher than normal embankment materialsdepending on where the embankment is in relation to the glasscollection source. The Committee decided to recommend thatthe Department of Transportation develop permissivespecifications and let the market place decide if it iseconomically feasible to use. It may be that wastefacilities will actually pay to have the material used byothers rather than landfill it, thus, making it economicallyfeasible. .

It was recommended that the Department of Transportationdevelop specifications for embankments using waste glass.

TIRES

The next area studied was the use of waste tires. It isestimated that Virginia generates approximately 3 to 4million waste tires a year. The ISTEA Bill requires Virginiato use 20i of waste tire rubber per ton of asphalt in 5% ofall federal aid asphalt pavements in 1994 and to increasethat use to 10% of the federal aid pavements in 1995, 15% in1996 and 20% in 1997 and beyond. virginia Department ofTransportation has developed specifications and a plan to usethe tire rubber in asphalt pavements as required.

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It was determined that while this use is required andwill be accomplished in accordance with the law, that morewaste tires could be used if permissive specifications weredeveloped to allow the use of waste tire rubber in embankmentconstruction.

The Department of Transportation undertook anexperimental project to use tire rubber in a 50% soil-tireblend to construct embankments. VDOT was able tosatisfactorily construct a fill of approximately 930 feet inlength, 4 lanes wide to a height of 20 feet using shreddedtires and soil. The experimental project used 2.5 milliontires and is performing well.

The cost of using tire rubber in embankment constructionwas more than using regular soil embankment but the Committeeconcluded that there may be some off sets in cost if thosewho are charged with disposing of waste tires were given theopportunity to support the construction activity by payingcontractors to use the materials. The contractor could usethe tires if the specifications were made permissive. Itwas, therefore, decided to recommend thatVDOT developpermissive specifications to allow the use of shredded tiresin embankment construction and let the economics of thesituation be worked out in the market place.

The Committee recommended that the Department ofTransportation develop specifications for tires inembankments. The Department of Transportation developed thespecifications.

PLASTICS

The next area studied was the use of plastics. Thereare certain products available that use plastics and recycledplastics. Most notable are polymers in asphalts, posts andguardrail block outs.

The Committee recommended that the Department ofTransportation continue to allow, and try to expand the useof recycle plastics.

The Department of Transportation is developingspecifications for the guardrail blocks and is seeking anexperimental project for the use of the posts"

YARD WASTE/WOOD PRODUCTS

The Committee looked into the use of yard waste and woodproducts. It was determined that the Department ofTransportation already uses wood waste as brush barriers for

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siltation control and wood chips as mulch. There arespecifications that allow processed wood waste in VirginiaDepartment of Transportation construction.

CONCRETE

The Committee looked into the use of recycled concrete~

It was determined that the Virginia Department ofTransportation already uses recycled concrete for fillmaterial~ VDOT also allows the use of crushed concrete foraggregate subbase materials and embankment construction~

The Committee recommended that VOOT consider the use ofcrush concrete pavements in new concrete construction. Thereare recognized problems with using recycled concrete in newstructural grade concretes but it was thought that theproblems may be solved through selective use.

The Virginia Department of Transportation agreed toexperiment in this area and has developed specifications forone project and will continue to look at the process throughits' Research· Council.

NEWSPAPERS/WASTE PAPER

The Committee looked into the use of recycling wastepaper into a useful highway construction material. It wasdetermined that this is already allowed under VDOTspecifications. Wasted recycled paper is used as mulchduring the seeding of highway ri9ht-of-way~

AGGREGATE FINES

The Committee also looked at the possibility of usingmore aggregate fines from quarry waste. No use was found foran unclassified fine aggregate, however, one area of possibleuse would be as embankme~t materials if they are mixed withenough suitable material to create a stable fill with CBRvalues as high as or higher than the available borrowmaterial. The virginia Department of Transportationspecifications already allow this use. The transportationcost may be prohibitive because the materials will becompeting with local soil material~

The Committee made no recommendation on this area as itwas thought that VDOT specifications would allow the use ofthe material if properly processed.

ROOFING MATERIALS

The Committee looked into the use of roofing materialsfor asphalt pavements. During the limited time thisCommittee had to work in this area, it was unable to

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determine that this was a viable product for highwayconstruction. No specifications or processes are known toalready exist. Inasmuch as roofing materials are made up ofasphalt and aggregates, it was deemed desirable toinvestigate further. There was concern that past consumerwaste was contaminated with nails and other foreign material.The industrial waste may generate a more acceptable material.

The Committee recommended that the Department ofTransportation have its Research Council conduct research inthis area for possible future use if it is found that areasonable supply of this material is" available and a properasphalt mixture can be developed.

There are patching materials in existence and theDepartment of Transportation purchases this type material.

RECYCLED BITUMINOUS CONCRETE

The Committee looked into the use of reclaimed asphaltpavement (RAP). It was determined that approximately 500,000tons of asphalt pavement is removed from city streets andhighways annu~lly. It was noted that asphalt pavements arecompletely recyclable.

The Committee determined that the VDOT was presentlyrecycling most of this material but had limits on theallowable percentages. The Committee recommended that theVDOT develop specifications to allow a greater use ofreclaimed asphalt pavement.

VDOT is developing specifications to allow for anincreased use of reclaimed asphalt pavements by allowingexceptions to maximum limits.

CONCLUSION

The Committee determined that there are many wastematerials that have a potential for recycling, butproducts/processes have not been developed for them, as ofyet. The Committee felt that it could only recommend thoseproducts outlined in this report. The Committee reco~mends

that the Review Committee be continued for a period of fiveyears to evaluate annually the Departmentrs progress inutilizing recycled products. The Co~mittee believes that itcould serve as a contact point for producers of recycledproducts and a clearinghouse for new ideas that mayor maynot have highway construction application. The Committeecould meet once a year to determine if the products haveany highway construction application and if they are producedin enough quantity to make them a viable item. The make up

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of the Committee is such that waste products would be evaluatedobjectively as state agencies, local governments, constructionindustry and recycling interest are all represented.

It was also decided that the most practical way to utilizerecycled products was to make sure thatspecifications were made permissive where there were products thathave proven performance. This is a constantly evolving area asmore and more products are developed and produced. Thisevolutionary process must be constantly monitored in order to bekept current on products, specifications and research.

RECOMMENDATIONS/ACTION

RECOMMENDATION

The Review Committee recommended a specification for use ofglass in highway embankments.

ACTION

The Department of Transportation developed a specificationfor recycled glass in embankment construction.

RECOMMENDATION

The Review Committee recommended a specification for the useof waste tire rubber in asphalt pavements in accordance with theISTEA Bill. Under this bill Virginia will have a plan to usewaste tire rubber in 10% of the federal-aid asphalt pavements in1995, 15% in 1996 and 20% in 1997 and beyond in accordance withthe law. If the law is changed, the plan will be reviewed tocomply.

ACTION

The Department developed a specification for the use of wastetire rubber in asphalt pavements.---------------------------------------------~---------------

RECOMMENDATION

The Review Committee recommended a specification for wastetire rubber in highway embankments.

ACTION

The Department developed a specification for the use of wastetire rubber in highway embankments.

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RECOMMENDATION

The Review Committee recommended that the Departmentallow recycled plastics in highway construction.

ACTION

The Department is developing specifications that willallow use of recycling plastics in fence post and guardrailblockouts. The research is complete in these areas and draftspecifications have been developed.----~--------------~---~~---~-----------~-----~--------------

RECOMMENDATION

The Review Committee recommended that the Department ofTransportation use wood waste where possible.

ACTION

The Department has specifications on wood cellouseproducts that will allow recycled wood in mulches.

RECOMMENDATION

The Review Committee recommended that the Department ofTransportation conduct research on the use of recycledconcrete in construction.

ACTION

~he Department has set-up a project that will allowwaste concrete to be reprocessed as an aggregate for newconcrete. The Department is also conducting research todetermine if a greater use of recycled concrete will befeasible from a performance standpoint.-~-~---~--------~-~-~-----~-~---------~~--~~-~-~---~---------

RECOMMENDATION

The Review Committee recommended that the Department ofTransportation make use of waste paper products.

ACTION

The Department has specifications to allow the use ofrecycled paper products as mulch------------------------~~---~-----------~------~~------------

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RECOMMENDATION

The Review Committee recommended that the Department ofTransportation conduct research on the use of recycled roofingmaterials.

ACTION

The Department will continue research in this area.

RECOMMENDATION

The Review Committee recommended that the Department developspecifications to allow the use of Recycled Asphalt Pavements inhighway construction.

ACTION

The Department has specifications to allow Recycled AsphaltPavements in highway construction.

RECOMMENDATIONS TO ENCOURAGE THE USE OF RECYCLED MATERIALS

The Advisory Committee was also charged with makingrecommendations to the Department on the components of a five-yearplan for encouraging the increased use of recycled glass and otherrecyclable materials in highway construction.

The Advisory Committee makes the following recommendations:

1. Remove impediments against recycling from specificationswhere equal or better products exist.

2. Continue to conduct research and perform evaluations ofrecycled products that are presented by manufacturers andhave credi table .background test resul ts.

3. Develop permissive specifications on recycled productsthat have proven records of performance.

4. Advise local governments who collect waste materials ofVDOT specifications which allow the use of certain wasteas recycled materials in highway construction.

5. Use the Technology Transfer courses conducted by theVDOT's Research Council to advise highway constructionagencies of new developments in the use of recycledmaterials.

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6. Advise DEQ of specifications that allow recycledmaterials as they are developed so they will be able toencourage the recycling industries of potential markets.

7. Use VDOT Research Advisory Committees to identify newrecycled materials that have highway constructionapplication.

8. Request cities and counties to provide VDOT or DEQinformation on all waste materials being diverted fromtheir waste streams that have potential highwayconstruction application.

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APPENDIX I

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1992 SESSIONVIRGl~IA ACTS OF ASSEMBLY - CHAPTER 2S S

An Act to amend the Code of Virginia b.\.' addmg In Article 1./ 01 Chapter J of Title 33.1a section numbered 33.1-23.5:2. retattng to use of certain recycled materials in highwa.\·construction.

IS 4691

Approved MAR 1 3 1992Be it enacted by the General Assembly of Virginia:

1. That the Code of Virginia is amended by adding in Article 1.1 of Chapter 1 of Title 33.1a section numbered 33.1-23.5:2 as follows:

§ 33.1-23.5:2. Use of recycled materials in highway construction.-The Department shallcreate a Recycled Materials in High way Construction Advisory Committee which shallinclude. but not be limited to: one person representing the Department. one personrepresenting the Virginia Roadbui/ders Association, one person representing the VirginiaAggregates Association. one person representing the Virginia Asphalt Association, oneperson representing the Virginia Waste Industries Association, one person representing theVirginia Department of Waste Management. one' person representing Virginians jarRecycling. Inc., and one person representing a Virginia local government or authoritywhich operates or contracts lor the operation 01 a recyclinS jacility. The AdvisoryCommittee shall make recommendations to the Department on the specifications to be setby the Department pursuant to this section. The Advisory Committee shall also makerecommendations to the Department on the components 01 a five-year plan jorencouraging the incrlNlMKJ use by the Department 01 recycled gltlSS and other recyclablematerials in Virginia highway projects. The Department shaD report to the 1994 Session 01the General Assembly actions taken to comply with the provisions 01 this section.

The Department. after receiving the recommendations 01 the Recycled Matenals inHighway Construction Advisory Committee. shall fi} set specifications, in coniunction withits road and bn'd8e specIfications and in all 01 its similar publications and documents.which authorize and govern the use 01 recycled glass as construction material inhighway·reiated construction in Virginia and (il) adopt a jive-year plan encouraging theincreased use by the Department 01 recycled glass and other recycled materials in Virginiahighway projects.

The Department shall maintain and make available to its contractors a list 01 the sitesin Virginia from which they may obtain recycled glass and other recycled materials joruse in Virginia highway construction projects.

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APPENDIX II

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USE OF WASTE GLASS IN HIGHWAY CONSTRUCTION (UPDATE -1992) - \vOODPQW J. HALSTEAD

ABSTRACT

Increasing pressures to recycle more wastes and minimize the amount of ma­terials placed in landfills are forcing reconsideration of potential uses of waste glassin highway construction and maintenance operations. The federal government andmany state legislatures are mandating studies to find such uses. Because the vol­ume of aggregate needed for highway construction is so large, the use of waste glassin this maDDer offers a potential for utilizing most ifnot all glass unsuitable for oth­er purposes.

This report provides the results of a literature search and telephone survey todetermine current (1992) practices of selected state highway agencies regarding theuse of crushed glass in highway construction. It is shown that similar viewpointsare held by most state highway agencies regarding such use:

1. Glass can be used as a component of unbound aggregates for embank­ments. trench backfills. back:fi.lls for walls. pipe bedding, gravel bases,ballast" etc.• and in hot-mix asphalt base courses and surfaces.

2. Waste glass is not economically competitive with available sources of nat­ural aggregates. nor is the available volume sufficient to reduce substan­tially the need for natural aggregates in a given geographical area.

3. No use has been made of glass in surfaces of main highways where highspeeds and heavy truck traffic exist.

4. Cities and towns have successfully used glass in asphalt surface coursesfor construction and maintenance of their streets.

5. Use in highway construction can be cost-effective as an alternative meansof disposing of waste glass collected in recycling programs where there isa need to avoid high landfill costs and conserve landfill space.

6. Cities and towns that have a public works department responsible forboth waste management (including recycling) and street maintenance ap­pear to be in the best position to use waste glass in a cost-effective man­ner. Cooperative efforts and mutually beneficial systems need to beworked out among waste management representatives, private recyclingfirms, highway construction agencies. and asphalt paving organizations.

Because local jurisdictions often have limited testing facilities. there is a rec­ognized need among state highway agencies to provide specifications and guidelinesfor use by cities and counties in their state. The trend is to provide for optional useunder established limitations.

Given a situation in which the use of waste glass is advantageous from an en­vironmental viewpoint, highway engineers generally prefer that its use be in em­bankments or as a portion of the aggregate in base courses. Less restrictions arenecessary for such applications. Larger u1ass particles and greater quantities can

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b. uaed. Upper permissible limits are not well estabHsbed. but lome states perwitup to 25 percent in embeDlaneuts, with stipulaticms that the top portiODa and Bia­of such embankments be all natural materials. Glue particl. with a maximnmsize of 2& DUD. (1 in) have been uaecl, and large particles may be acceptable. Simi­larly, when used for backfill of trenches, etc., lese restriction on the size anelamounts of ,lau is required.

Becauae street and road m';Dien 8DCft or rehabilitation is likely to 01l'er pat­er opportmlity to use wute glus in urban locatiou thaD. in D8W coD8trac:ticm, theuse ofwute g1au as a portion of the agregate in hot asphalt m:ixturee for~'put'PO_ is of coD8iclerable interest in such locatioDS. Conc:ems that have not beenfully evaluated iDclude the following:

• long-term stripping

• effects on skid resistance

• degree to which pullout of glass particles from the surface may create hazeards to tires or persons (especially for residential streets)

• effects of glass in pavements to be recycled

• e1fects of glu8 handling and additions of glass during the mjxing procel8on compliance with the regulations of the Environmental ProtectionAgency or health

• eff'ects of the use of glass on established production procedures and mate­rial supplies. If the portion of the aggregate being displaced by the glassis part of the normal production stream and must be removed and wastedin order for the glass to be used. nothing will have been accomplished ex-cept to change the identity of the waste material. ,

**Complete report "Use of \vaste Glass in Highway Construction (update - 1992)by \voodrow J. Halstead, Research Consultant may be obtained from theState Materials Engineer1s office.

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