PA’s New Joint Density Incentive/ By: Garth D. Bridenbaugh ... · materials costs. The research conducted during NCHRP Report 452 (McDaniels et al., 2001), and later adopted by

3540 NORTH PROGRESS AVENUE, SUITE 206 ♦ HARRISBURG, PENNSYLVANIA 17110-9637 ♦ 717-657-1881 ♦ FAX 717-657-0687

WEBSITE: www.pahotmix.org E-MAIL: [email protected]

PENNSYLVANIA ASPHALT PAVEMENT ASSOCIATION

Pennsylvania rides on us … ASPHALT

PA’s New Joint Density Incentive/PA’s New Joint Density Incentive/ Disincentive SpecificationDisincentive Specification

A new era has begun regarding

HMA longitudinal joint construction on many

of Pennsylvania’s higher volume roadways.

Beginning in July 2010 PennDOT began

including a new longitudinal joint density

specification as a special provision in a

number of contracts with a goal of improving

joint density and, hopefully, joint perform-

ance. Before discussing the new specification

in detail, it is important to understand why

such an effort was undertaken. Many other

states, as well as PennDOT in recent years,

are focusing efforts on the longitudinal joints

due to poor performance at this vulnerable

area of the pavement. (Figure 1) While

mixture design plays a key role in producing

durable pavements, achieving optimal field

density is also vital to long term pavement

performance along the joint.

Until recently the Department had

that resulted from using these best practices

and paying closer attention to joint

construction. This represented the first real

data that was collected on PA’s joint densities,

and the effort to obtain information continued

in 2008 and 2009. The training on best

practices and increased scrutiny on joint

construction prior to the 2008 construction

season paid off with a 1.1% increase in joint

density in one year. (Figure 2) However, the

data showed that many projects still were not

achieving optimal joint density.

For 2010 the Department took a

new approach to joint construction. Instead of

dictating “best practices” means and methods

to the contractor, on higher volume roadways

PennDOT would provide a performance

specification with an incentive or disincentive

for the joint density. This new approach was

communicated in Strike-off letter 424-10-02,

HMA Longitudinal Joint Density Incentive/

Disincentive Specification, which was issued

June 3, 2010. In essence the contractors are

able to choose their own methods to achieve

Figure 1

Failed joint material being removed at centerline

(shoulder joint already replaced)

INSIDE THIS ISSUE:

PA’s New Joint Density 1

PennDOT Letting Schedule 3

Are We Understanding How To Use Higher RAP Percentages

4

President’s Message 7

Board Slate 7

Environmental Update 8

From Roof to Road ~ The Odyssey of Recycled Shingles

10

PAPA Active In APA Efforts 11

HMA Permeability… 12

Price Index 16

By: Garth D. Bridenbaugh, P.E. PA Department of Transportation Bureau of Construction and Materials Team Leader Districts 2 & 9

no measure of the actual densities achieved when

constructing the joint. In 2006 and 2007 PennDOT

and PAPA worked together to

evaluate joint construction

methods and began to gather

data on joint density. “Best

Practices” for joint construction

were developed and distributed

statewide, and training was

conducted at many venues

across Pennsylvania. Beginning

in 2007 a joint density baseline

was established to track the

progress and improvements

Continued on page 2...

Longitudinal Joint Data Summary

Year Projects Avg. Joint Density Avg. Roadway Density

2007 18 87.8% 93.9%

2008 43 88.9% 94.1%

2009 29 89.2% 94.1%

2010 Contractors gathering data for PWT spec.

Figure 2. Density Improvements Using Best Practices

2 • Paving the Way April—June, 2010 www.pahotmix.org

...Continued from page 1 collected joint density information from other 2010 paving projects

which will serve them well as paving under the new specification

approaches. Noted below are joint density results (done in

accordance with the new special provision) from three contractors

who used distinctly different joint construction methods.

Contractor A used the prescriptive “best practice”

approach that has been in place for the last few years. Contractor

B milled back into the cold mat in order to create a vertical face to

restrain the edge of the hot mat and to remove the less dense

material at the unrestrained edge of the cold mat. Contractor C

purchased and used a vibrating wedge compactor (Figure 5)

purported to increase joint density by 1 % to 2%. Contractors A, B

and C reported joint densities around 88, 92 and 90, respectively.

These results indicate that even with the

use of “best practices” there may be difficulties

achieving target densities and incentives under the

new special provision. The results also indicate

that there are joint construction practices that will

help improve field densities.

It remains to be seen how much

improvement in joint density will be achieved

under the new specification. However, one thing is

for sure, the paving contractors of Pennsylvania

have more incentive than ever to deliver high

quality joint construction.

In conclusion, by providing a financial

component and allowing the contractor the

flexibility to use innovative approaches, it is

anticipated that joint density and, therefore,

long-term performance will increase due to the new

specification.

Figure 3. Schematic core locations on the joint from PTM 729

Figure 5. Vibrating Wedge Compactor

Increased Joint Density at least 1%

performance to earn an incentive for delivering high density at the

joint. Conversely, a disincentive is assessed for achieving low joint

density.

The special provision is based on

a statistical approach of calculating percent

within tolerance (PWT) based on the

average and standard deviation of the

individual core specimen density test results.

The lower specification limit has been set at

89% of Gmm, and lots with averages below

89% will begin to receive a disincentive.

As density values move further below the

89% limit, the disincentive grows

progressively larger to a maximum of

$6,000 per lot. Additionally, lots with

average density lower than 88.0% will

require a corrective action of overbanding

the joint with PG binder material. For

densities which calculate above 80 PWT, the

contractor will begin to receive an incentive

payment which progressively increases as

density increases to a maximum of $2,500

per lot. These incentive and disincentive

maximums are reduced to half of the full values in the first year.

Beginning with the 2011 initial edition of Publication 408, the full

values of $5,000 maximum incentive and $12,000 maximum disin-

centive will apply.

Contracts specifically targeted for the new specification are

those which have either RPS wearing courses on any roadway or

standard wearing courses on the National Highway System where

density acceptance is via pavement cores. Additionally, projects must

have a minimum of 12,500 feet of testable joint construction to

qualify. Contractors are required to cut one core at the newly

constructed longitudinal joint for every 2,500 lineal feet of joint.

(Figures 3 & 4) The specification only applies to surface courses and

newly constructed joints where mats on both sides of the joint were

placed as part of the contract.

For the 2010 construction season a number of contractors

across the state have begun collecting information on their joint

densities. While none of the projects let since July 2010 with the

new specification have yet been constructed, several contractors have

Figure 4. Cutting a core

directly over the joint

ALL STATES MATERIALS GROUP Mark L. Edsall, Technical Marketing

325 Amherst Road

Sunderland, MA 01375

Phone: 800-343-9620 * Fax: 413-665-9027

Website: www.asmg.com

HESS ENERGY

Joseph Wright, Sales Manager

867 Berkshire Boulevard., Suite 101

Wyomissing, PA 19610

Phone: 610-371-2005 * Fax: 610-378-7990

Website: www.hessenergy.com

LENNON, SMITH, SOULERET ENGINEERING, INC. Kevin Brett, P.E., Principal / Engineering Manager

846 Fourth Avenue

Coraopolis, PA 15108

Phone: 412-264-4400 * Fax: 412-264-1200

Website: www.lsse.com


Following is the tentative Letting Schedule for Construction Year 2011:

January ………………….………….…… 6 and 20

February ……………………………..…… 3 and 17

March …………..………….……….… 3, 17 and 31

April …………...……………………..…. 14 and 28

May ………….……………………..…..… 12 and 26

June ……………………………………..... 9 and 23

July ……………...……………………….... 7 and 21

August …………………………………….. 4 and 18

September …………………………… 1, 15 and 29

October …………………………….……. 13 and 27

November …………………..…….……………... 10

December …………………………..……. 1 and 15

LIBERTY TIRE RECYCLING Doug Carlson, Vice President Asphalt Products

625 Liberty Avenue, Suite 3100

Pittsburgh, PA 15222-3115

Phone: 412-562-1700 * Fax: 412-562-0248

Website: www.libertytire.com

MACK TRUCKS, INC.

Patrick Meehan, Vice President

2402 Lehigh Parkway South

Allentown, PA 18103

Phone: 610-351-8800 * Fax: 610-351-8737

Website: www.macktrucks.com

SPECIALIZED ENGINEERING Jennifer Leatherman, Manager

4845 International Boulevard., Suite 104

Frederick, MD 21703

Phone: 301-607-4180 * Fax: 301-662-6122

Website: www.specializedengineering.com

Following is the tentative Letting Schedule for Construction Year 2012:

January ……………….………….…… 12 and 26

February ………………………………………..… 9

March ………….………………….… 1, 15 and 29

April …………..…………………..…... 12 and 26

May ………….……………………..…… 10 and 24

June ………………………………………. 7 and 21

July ……………...…………………….. 12 and 26

August …………………………………... 9 and 23

September ……………………………. 13 and 27

October ……………………………….…. 4 and 18

November ………………..……………..………... 1

December ………………………..……. 6 and 20

Reclaimed asphalt pavement (RAP) has been used for several decades

in hot mix asphalt (HMA) to make use of a valuable resource and reduce

materials costs. The research conducted during NCHRP Report 452 (McDaniels et

al., 2001), and later adopted by AASHTO M323, Superpave Volumetric Design, recommends that when RAP percentages are under 15%, the contribution (or lack

of) of the RAP is ignored and assumed to have no impact on the final mixture

performance. At percentages between 15% and 25% RAP, it is recommended

that one grade softer in the virgin asphalt be used. If RAP percentages greater

than 25% are specified, AASHTO M323 recommends the use of Blending Charts.

However, as more emphasis has been placed on utilizing higher

percentages of RAP in HMA, researchers are discovering that it may not be as

easy as what was originally thought. Issues pertaining to the actual blending of

RAP and virgin binders had raised questions regarding the accuracy of blending

charts. Meanwhile, volumetric measurements, in particular voids in mineral

aggregate (VMA), become even more difficult as the specific gravity of the RAP

aggregate play a more predominant role in the VMA calculations. Ultimately,

state agencies may eventually move towards performance testing as a means of

accepting higher RAP content mixtures, but which test should be specified? And

if performance testing is the answer, what criteria should be used? Some of

these issues are reviewed herein.

Blending of RAP and Virgin Asphalt Binders One of the issues with utilizing blending charts to determine

appropriate levels of RAP in asphalt mixtures is that it assumes a condition that

the RAP asphalt binder fully blends with the virgin asphalt binder. However,

research suggests that this may not be the case and the extent of blending is

probably somewhere between 0% (called Black Rock) and 100% (simulated by

extraction and recovery). If the asphalt binders never reach 100% blending, then

the performance of the RAP/HMA mixture will be based on what is known as the

“effective” binder properties of the RAP/HMA mixture. A graphical description of

the blending possibilities is shown in Figure 1 (after McDaniel, 2009). In Figure

1a, the RAP particle, containing the RAP aggregate with oxidized asphalt binder

film, is introduced to the mixing process. During mixing, asphalt binder is

applied to the mixture and begins to coat the RAP particle (Figure 1b). If the

RAP and virgin binders do not blend, the effective binder properties will be those

of the virgin binder only (Figure 1c). This also creates an under-asphalted

condition as virgin binder is “robbed” from virgin aggregate as it coats the RAP

particle, which includes the oxidized RAP binder that was assumed to contribute

to the total asphalt content of the mixture. If the RAP and virgin binders do

merge, the effective binder properties will be dependent on the amount of

blending that occurs (Figure 1d). It should be noted that a number of factors

will influence the degree of blending, including; RAP source, time of mixing, time

at which RAP and mixture commingle at elevated temperatures, and asphalt plant

type (batch or drum) to name a few.

(a)

(b)

(c)

(d)

Figure 1 – Schematic Potential Blending Conditions of RAP

and Virgin Binders (After McDaniel, 2009)


By: Thomas Bennert, Rutgers University &

Robert Sauber, Executive Director New Jersey Department of Transportation



Although methods are not currently available to accurately

determine the actual degree of blending between the RAP and virgin

binders, procedures are currently being explored that can provide an

estimate as to whether or not blending does exist (Bonaquist, 2005;

Bennert and Dongre, 2010). The procedure utilizes the RAP/HMA

mixture stiffness properties, as determined from the Asphalt Mixture

Performance Tester (AMPT), and the asphalt binder stiffness properties

from the extracted asphalt binder of the RAP/HMA mixture. Once

determined, comparisons of measured versus predicted mixture

stiffness, or measured versus predicted asphalt binder stiffness, can be

computed using what is known as the Hirsch model (Christensen et

al., 2005). The Hirsch model is a predictive model that was

developed to predict the stiffness properties of asphalt mixtures by

simply knowing the asphalt binder stiffness and volumetric properties

of the asphalt mixture. Figures 2a and 2b show examples of different

levels of blending between the RAP and virgin asphalt binder.

The procedure is based on the assumption that the

extraction and recovery process completely mixes the RAP and virgin

binders during the recovery process, thereby simulating a condition of full blending. By utilizing the Hirsch model, it is then possible to predict what the mixture

modulus should be if full blending did occur. For 0% RAP, blending is not an issue and the predicted and measured values should show good agreement, as can be

seen in Figure 2a. Deviations between the predicted and measured modulus values would indicate that full blending between the RAP and virgin binders may have been

compromised due to production and material properties. Again, it should be noted that this procedure cannot determine the exact degree of blending, however, it does

provide a means of evaluating if full blending is occurring or not. The same methodologies are also being applied in the use of recycled asphalt shingles (RAS).

Determining Bulk Specific Gravity of RAP Aggregates When utilizing higher percentages of RAP, it becomes increasingly important to accurately determine the bulk specific gravity properties of the RAP aggregate

for the computation of the voids in mineral aggregate (VMA). Two methods have been recommended to determine the bulk specific gravity of the RAP aggregates

(McDaniel and Anderson, 2001; Christensen and Bonaquist, 2009); 1) Estimate the bulk specific gravity of the RAP aggregate from the RAP binder content, the maximum

specific gravity of the RAP, and estimates of the binder absorption in the RAP and the specific gravity of the RAP binder; and 2) Measure the bulk specific gravity of the

coarse and fine fraction of the RAP aggregate after removing the binder with the ignition oven or solvent extraction.

Figure 2a – Examples of Different Degrees of Blending Between RAP and Virgin Binders

...Continued from page 4

Figure 2b – Examples of Different Degrees of Blending Between RAP and Virgin Binders



Both NCHRP Report 452 (McDaniel and Anderson, 2001) and the

upcoming NCHRP 9-33, A Mix Design Manual for Hot Mix Asphalt (Christensen and Bonaquist, 2009), have recommended the use of the RAP binder content,

RAP maximum specific gravity, and estimates of the asphalt binder absorption

of the RAP aggregate to estimate the bulk specific gravity of the RAP

aggregate. In this procedure, the effective specific gravity is first estimated

using the following equation.

where,

Gse = effective specific gravity of the RAP aggregate

Gmm = maximum specific gravity of the RAP

Pb = RAP binder content (%)

Gb = estimated specific gravity of the RAP binder

The bulk specific gravity of the RAP aggregate can then be estimated

from the following equation using the previously estimated effective specific

gravity (Gse).

where,

Gsb = estimated bulk specific gravity of the RAP aggregate

Gse = effective specific gravity of the RAP aggregate

Pba = estimated binder absorption of the RAP (wt% of aggregate)

Gb = estimate specific gravity of the RAP binder


Christensen and Bonaquist (2009) noted that the accuracy of

estimating the RAP aggregate specific gravity from the above procedure

depends most on the accuracy of the RAP binder content and the accuracy of

the assumed binder absorption of the RAP aggregate. Through additional

statistical analysis, the authors suggest that the error should not exceed more

than 0.2% for the estimated asphalt content of the RAP in order to obtain

estimated RAP aggregate specific gravity values with similar accuracy as those

measured in AASHTO T84 and T85. This puts tremendous emphasis on an

accurate and appropriate ignition oven correction factor, which most asphalt

suppliers use to quickly estimate the asphalt content of their RAP stockpile.

If a reasonable estimate of the asphalt binder absorption of the

RAP aggregate is not available, Christensen and Bonaquist (2009) also

recommend either using extraction/recovery or the ignition oven to remove the

asphalt binder and then measure the coarse and fine fraction of the RAP

aggregate using AASHTO T84 and T85 to determine the bulk specific gravity

properties. However, it should be noted that even this procedure may have

its drawbacks as it has been proposed that different extraction processes (i.e.

– reflux, centrifuge, and ignition oven) may alter the physical properties of

the RAP aggregate. Research regarding this is currently on-going at the

University of Nevada-Reno and the National Center for Asphalt Technology

(NCAT). Unfortunately, when utilizing higher RAP percentages, these

compounding errors could result in changes in the reported VMA. An example

of this is shown in Figure 3 (West, 2010). Although the differences may not

be extremely large, it could be problematic for asphalt mixtures designed at

the minimum VMA. Therefore, when utilizing higher RAP asphalt mixtures,

greater amounts of testing/evaluation and quality control are recommended,

and in most cases necessary, to ensure good performance.

References

Bonaquist, R., 2005, New Approach for the Design of High RAP HMA, Presented at the 2005 Northeast Asphalt User’s Producer’s Group Meeting,

Burlington, VT, October 19th to 20th, 2005.

Bennert, T. and R. Dongre, 2010, “A Backcalculation Method to Determine

“Effective” Asphalt Binder Properties of RAP Mixtures”, Presented and

Published at the 89th Annual Meeting of the Transportation Research Board

(TRB), January 10th to 14th, 2010, Washington, D.C.

Christensen, D. and R. Bonaquist, 2009, A Mix Design Manual for Hot Mix Asphalt – Preliminary Draft Final Report, National Cooperative Highway

Research Program (NCHRP), Transportation Research Board, National Academy

Press, Washington, D.C., 363 pp.

West, R., 2010, Proposed High RAP Content Mix Design, Presented at the Northeast Asphalt User Producer Group (NEAUPG), Saratoga Springs, NY,

October 6th to 7th, 2010. Figure 3 – Change in VMA Due to Inaccuracy in Gsb Estimation of RAP Aggregates

PENNSYLVANIA

ASPHALT

PAVEMENT

ASSOCIATION

OFFICERS

Chris Kaminski President

Vince Tutino Vice President

Robert Meeker Treasurer

Gary L. Hoffman, P.E. Secretary / Executive Director

BOARD OF DIRECTORS

Patrick Hawbaker Chris Kaminski Term expires 2010

Steve Bright Donald Overdorff Term expires 2011

James B. Barley C. Douglas Brown Kerry Drake William R. Hinds, Jr. Owen J. McCormick Robert G. Meeker Vince Tutino John B. Warden III Term expires 2012

Brock Myers Term expires 2013

Barry Duffy Mark E. Kendrick Richard A. Raffo Term expires 2014

Timothy Rice Donald Rosenbarger Term expires 2015

EX-OFFICIO MEMBERS

Francis J. Colella Kim W. Snyder Daniel R. Hawbaker John R. Kibblehouse, Sr.

TECHNICAL COMMITTEE CHAIRMAN

Jeffrey Frantz


Wow, where has the year gone?

Coming up on our Annual meeting and

closing out the year. It’s been a rough ride

(not on our asphalt roads of course). Funding, the political scene, extreme heat in

the summer, wet weather in the fall. Not

to mention the continued poor economy

and the constant concern over highway funding for the future.

We should give thanks to the outgoing Governor for his last ditch effort to

increase highway funding. Hopefully, his efforts will help for the coming year.

We should also embrace our incoming Governor Elect Tom Corbett and his

new administration in these trying times. We look forward to working with

the Governor in the coming four years.

I had the opportunity recently to visit the Pittsburgh area for the

Marcellus Shale Conference. What an economic boom for the area. I toured

around a couple of drill sites for the natural gas extraction. This has been a

win-win for the property owners, the companies doing the work, and our

industry overall for our energy costs. Natural gas prices are at an all time

low! It is great to see several of our member companies located in the area

benefiting with the increased site and road construction.

I look forward to seeing everyone at the December Conference at

Hershey. We hope to have another great year for attendance. Please

encourage and support your appropriate staff members to attend. Gary

Hoffman and staff have put together an excellent agenda.

Chris Kaminski

President

Christopher Kaminski President

SEMINARS A SUCCESS The Association, in June, held Environmental Update Seminars

at locations in eastern and western Pennsylvania. Topics covered in the

seminar included final updates to the federal Spill Prevention Control and

Countermeasure regulations, the General Permit for the beneficial use of

asphalt shingles in hot mix asphalt production, and technical information

on Warm Mix Asphalt (WMA). Also receiving attention was the DEP

General Operating Permit related to air emissions, and the use of porous

pavement. Porous pavement is an attractive product, which is receiving

increased attention throughout the Commonwealth due to tighter

stormwater regulations.

A new topic which the Association’s Environmental Committee is

keeping an eye on is a federal EPA initiative related to used oil. A very

significant percentage of used oil is consumed at asphalt plants, but as a

result of a court decision, EPA is revisiting the subject of which used oil

is considered “solid waste”, and which is not. The issue is of importance

because used oil which is considered to be a “solid waste”, would require

more stringent controls at the burning location to see if it has “maximum

achievable control technology” air emissions controls. The Association will

keep you informed on this important issue.

DEP proposed earlier this year to tighten standards under the

Act 2 Land Recycling program for arsenic and Benzo(a)pyrene. While the

arsenic standard, if tightened, would only have an indirect affect on clean

fill limits, the lower limit for Benzo(a)pyrene is of great concern to the

industry. Essentially, if the Benzo(a)pyrene standard is tightened from 2.5

to 0.57 mg/kg as proposed, then more materials would not be clean fill,

particularly in areas where there was historic coal burning. Deposits of

atmospheric emissions can exceed the proposed limits. DEP, at the

request of the Association, has evaluated whether a different limit could

apply for clean fill as compared to the Act 2 Land Recycling program.

The lower limit is proposed to be put through by the

Pennsylvania Department of Environmental Protection, based on updated

risk assessment/toxicological information from EPA, and the lower limit

has been placed into effect in other states, including New Jersey. This

issue is of concern due to

Pennsylvania’s historical

extensive coal burning, so we

will keep you informed on

this issue as well.

It is important

that those in charge of hot

mix asphalt plant operations,

and in particular, those in

charge of environmental

management elements, be

be aware that the Association offers “technical assistance” when permitting

or other environmental compliance issues arise. This service is offered free

through the Association office and is available to all PAPA members.

Members should be aware that from time to time, the Association may be

coordinating with DEP on new interpretation issues, and if issues of an

environmental nature are raised at your plant, which don’t reflect the

industry position, we would urge members to check in for technical

assistance to avoid problems.

Recent technical assistance requests to the Association have

included information on which type of structures and tanks are and are

not exempt from the final Spill Prevention Control and Countermeasure

regulations, what types of tank wall thickness testing are needed under

the SPCC regulations, and questions regarding use of the new General Air

Operating Permit. Mr. Gary Hoffman, P.E., Executive Director, should be

contacted for technical assistance.

The Association is also updating its Environmental Guide, which

was distributed free to all those who attended the Environmental Update

Seminars. Any members who would like a CD copy of the updated guide

should contact Walter Hungarter at RT Environmental Service, Inc. at

800-725-0593 Ext. 238 or by email at [email protected].

CLEAN FILL LIMITS WILL NOT BE CHANGED There was much concern in the construction industry that if

DEP were to change the Statewide Health Standards that materials could

be affected, including soils and aggregates, as they are moved from site

to site. Information from Harrisburg is that DEP will proceed with

revisions to the Statewide Health Standards under the Act 2 Land

Recycling Program, but they will not change Clean Fill Limits.

The Association has worked with Pennsylvania DEP since 1998

to make sure that there are reasonable standards applied to materials,

particularly those which are not believed to be contaminated. There will,

however, be certain situations where materials may be questioned if they

are below the new, lower Statewide Health Standards for arsenic and

Benzo(a)pyrene, where materials are to be used on residential properties.

As the majority of residential developments do not involve substantial

quantities of fill, and as DEP will not change Clean Fill Limits on an

overall basis, the revisions to the Statewide Health Standards for arsenic

and PAH compounds are not anticipated to have a major affect on the

industry.



By: Walter Hungarter

RT Environmental Services

mailto:[email protected]


USE OF GENERAL PERMIT AND/OR CO-PRODUCT

DETERMINATION FOR MANAGEMENT OF RECLAIMED

ASPHALT PAVEMENT (RAP) It has come to the attention of the Association that incomplete

information is being given out to members when questions come up on

what permits are and are not needed when reclaimed asphalt pavement is

reused. Specifically, a co-product determination is available for certain

RAP uses, and a General Permit has been available since April 2003 for a

number of RAP management methods.

Specific information you need to know is as follows:

Milled and reclaimed asphalt pavement (RAP) is considered

a residual waste and must be appropriately managed

under Pennsylvania Department of Environmental

Protection Residual Waste Regulations.

Un-milled pavement, which is broken pavement (only), is

considered “clean fill”.

Hot mix asphalt product, which is not placed and

compacted as pavement, is considered a Pennsylvania

residual waste and must be returned to the plant for

reprocessing or managed as residual waste generally by

landfill disposal.

Once millings/RAP are produced at a particular road site,

a number of beneficial uses may be allowed. If the

co-product determination is used for the beneficial use

only, no processing may occur.

If further processing such as crushing occurs, or if the

material is stored offsite from where it was produced, a

General Permit must be applied for and be placed into

effect before the offsite storage or processing takes place.

The easiest way to think of the situation is this:

The co-product determination is applicable at the

point of use, where the beneficial use of the RAP

takes place.

The General Permit must be used whenever there is

processing or stockpiling away from the location

where the roadway is milled, where the RAP is

produced.

The final two considerations are these:

Stockpiles of RAP at hot mix asphalt plants are limited to

storage duration of one year, unless a General Permit is

applied for and is in effect.

Where milling/RAP are returned to a hot mix asphalt

plant, if there is no General Permit in effect, the only use

of that material allowed is to recycle the RAP back into

hot mix asphalt. In this instance, the stockpiling dura-

tion is limited.

Please call the Association office or Walter Hungarter at RT

Environmental Services, at 800-725-0593, ext. 238 if any questions.


Protection Agency testing results have been negligible for the presence of

asbestos, there is still a perception to be addressed. States’ experiences have

shown proper precautions can be taken to use post-consumer roofing shingles

safely and successfully.

With an estimated 11 million tons of asphalt shingles disposed of

each year in the United States, the potential for recycling this product is large.

Schram says, “Landfill diversion is the main environmental driver to using post-

consumer recycled materials. Being able to reuse instead of dispose of

something is a benefit to future generations. There is also a financial incentive

to the asphalt paving contractors, especially here in Iowa where the Iowa DOT

pays for liquid asphalt separately from the rest of the pavement mixture.

Shingles contain 25 to 30 percent

asphalt, where paving mixtures

typically contain only 5 to 6 percent.

Adding 5 percent recycled asphalt

shingles to the paving mixture could

reduce the purchase of liquid asphalt

by nearly 20 percent. “The Iowa DOT

recently approved a developmental

specification for use of recycled

shingles. Two projects have already

been constructed and five more are

planned using the recycled material.

“We are collecting a lot of data on

the current projects over the summer.

We’ll be looking very closely at

pavement performance on these

projects. If the performance is at the

level we expect, using recycled shingles could become a fairly standard practice.

We anticipate the use of this material will be in the supplemental specifications

in October 2011.”

WARM MIX ASPHALT

In what would be a radical change to the way asphalt pavements

are produced in Iowa, asphalt shingle materials may complement another

emerging technology, warm mix asphalt, which will likely replace the current

hot mix standard.

“Using warm mix instead of hot mix asphalt has many environmental

benefits,” said Schram. “Asphalt plants can operate at lower temperatures and

reduce greenhouse gases. Operating at lower temperatures also saves on fuel

consumption, reduces emissions and odor associated with the petroleum-based

product, and does not age the asphalt as much in the production process.

Because of this reduction in aging, there is potential for use of more recycled

materials, such as shingles without an effect on performance.”


Whether driven by environmental concerns, monetary motivations or

other reasons, people finding new ways to use old or unwanted items continues

to provide innovative technologies in many different fields, including

transportation. One product now being studied in Iowa as an additional source

of road-building materials is recycled asphalt roofing shingles.

According to the Northeast Recycling Council, asphalt shingles make

up roughly two-thirds of the U.S. residential roofing market. These products are

made of the same four basic materials contained in the hot mix asphalt used

to build roads: fiberglass or cellulose backing; asphalt cement; sand-sized,

ceramic- coated aggregate; and a mineral fiber or stabilizer that includes

limestone, dolomite and silica.

Scott Schram, Iowa DOT

bituminous engineer, says the reusable

shingles come from two different

sources. “The market includes both

post- and preconsumer shingles,” said

Schram. “Postconsumer shingles are

not yet widely accepted by states using

recycled materials in road building

mainly because the impact to

performance is not known. Pre-

consumer materials, which include

shingles that have for one reason or

another been rejected by the

manufacturer and have never been

used on a roof, are permitted in other

states, including Texas, Georgia,

Minnesota, Massachusetts, Indiana, New

Jersey, Pennsylvania, North Carolina, South Carolina and Missouri. Still, the

greatest potential for landfill diversion lies in post-consumer shingles, which has

led to the DOT’s participation in a pooled-fund study along with neighboring

states Missouri, Minnesota, Wisconsin and Illinois.”

Following the lead of our neighbor states has provided information

including the benefits and drawbacks of post-consumer shingles. Schram says

research shows the main issue with post-consumer shingles is the effect the

shingles have on the overall mixture performance behavior. “The asphalt binder

grade used to manufacture roofing shingles is much stiffer than grades used in

paving. When exposed to the elements for a number of years, the material

becomes highly oxidized and extremely stiff. With post-consumer product, you

don’t know whether those singles have been on a roof for five years or 20,”

said Schram. “These stiffer materials may require blending with virgin binders

that are softer than typical to ensure the pavement can perform well at low

temperatures. The fibers in the shingles may also provide a benefit, but the

possible presence of asbestos poses another issue. While shingles have not been

manufactured with asbestos for more than 30 years and U.S. Environmental

By: Tracey Bramble Office of Multimedia Services Iowa Department of Transportation

Pennsylvania Rides On Us … A S P H A L T

The Asphalt Pavement Alliance (APA) is a coalition of the

Asphalt Institute, the National Asphalt Pavement Association, and the

State Asphalt Pavement Associations. The Alliance's mission is to further

the use and quality of hot-mix asphalt pavements. The APA will

accomplish this through research, technology transfer, engineering,

education, and innovation.

Since early 2010, the Asphalt Pavement Alliance (APA) has

achieved a historic degree of industry unity and simultaneously launched

its new campaign in support of asphalt pavements. PAPA was the first

state association to provide financial support for and is active in these

worthwhile efforts.

The APA has already published numerous new resource

materials this year, a number of which PAPA has already put to great

use, in the topics of Economics, Engineering, Environmental, and Policy.

All of these documents can be found on the APA’s new website at

www.asphaltroads.org. There is a link to this website on PAPA’s website www.pahotmix.org. Some examples of how these documents have already been

used by PAPA are:

HOUSE TRANSPORTATION COMMITTEE HEARINGS

The Pennsylvania House Transportation Committee held seven

hearings across the state this past summer and fall to publicize the need

for increased transportation infrastructure investment. PAPA provided

testimony at each of these hearings that revolved around the

“Smoothness Matters...A Lot” theme and linked the cost of rough roads

to the motorists (TRIP report). The APA “Smoothness Matters” and “Jobs

in Asphalt” documents were distributed at each hearing.


MEETINGS WITH PENNDOT DISTRICT EXECUTIVES PAPA has met with each of the PennDOT District Executives

and their staffs to discuss performance and environmental benefits of

asphalt pavements. APA documents like “Smoothness Matters”, “Quiet

Pavements”, “Recycling and Energy”, “Perpetual Pavements” and “Speed

of Construction” were very useful in these discussions.

DISCUSSIONS WITH PENNDOT ON ALTERNATE BIDDING PAPA is continuing discussions with the DOT executives and

managers on the Department’s alternate bidding policies. APA

publications “Life Cycle Cost”, “Pavement Type Selection” and “Successful

Alternate Bidding” are being used in these discussions.

These new APA documents have much value and potential for

use with our stakeholders. However, they have to be used to provide

any value. You are strongly encouraged to go to the website, review

and use these documents with your stakeholders as opportunities arise!!!

For more information about the Asphalt Pavement Alliance

Call 1-877-APA-0077 E-mail: [email protected]

www.AsphaltRoads.org

By: Gary L. Hoffman, Executive Director Pennsylvania Asphalt Pavement Association


Fig

ure

1

Ka

rol-

Wa

rne

r p

erm

ea

me

ter

use

d f

or

this

re

sea

rch

By: Mansour Solomanian, Ph.D., P.E., Director Pennsylvania State University NE Center of Excellence for Pavement Technology Larson Transportation Institute

OBJECTIVE In general, it is desirable to limit the permeability of

dense-graded hot-mix asphalt (HMA) pavement to prevent the ingress of

water, which potentially could result in premature

failure of the pavement. A study was sponsored

by PennDOT and conducted by Penn State to

determine the permeability of laboratory-prepared

specimens and field cores and the correlation

between the two. Six mixes were included in the

study. Two of the tested mixes were Superpave

mixes with 12.5-mm nominal maximum aggregate

size (NMAS). The remaining four mixes were

9.5-mm NMAS Superpave mixes.

TESTS The Karol Warner permeameter was

used to determine permeability of HMA specimens

(Figure 1). Briefly, the equipment consists of a

metal cylinder to house the specimen and a

graduated cylinder to provide the falling

headwater to permeate through the specimen. A

rubber membrane inside the metal cylinder is

pressurized to seal the specimen walls and to

prevent water flow around the specimen. In the test procedure, first the

specimen is subject to vacuum saturation. To begin the test, the graduated

cylinder is filled with water to a marked level. The water head drops as

permeation through the specimen takes place. The rate of vertical flow of

water is determined based on the amount of flow within a specific time.

RESULTS In general, results indicate that field cores have a higher permeability

than lab-prepared specimens for a similar range of porosity (Figure 2). Porosity

is defined as the volume of water permeable voids as a percent of the total

volume. Compare this with air voids which is defined as volume of voids

(regardless of whether these voids are water permeable or not) as a percent of

the total volume. The porosities for which values are reported range from

almost 1 percent to as high as 12 percent.

Based on overall analysis of data and criteria used by

some other states, it is recommended that 1.25x10-3 cm/sec and 1.5x10-3 cm/sec

be considered as the upper limits of permeability for SGC specimens and field

cores, respectively.

Results for the six mixes are shown in Figures 3 through

8. All are presented on the same scale (i.e. 0 to 10x10-3 cm/sec). The obvious

conclusion from these measurements was that, in general, permeability increases

0.0

1.3

2.6

3.9

5.2

6.5

7.8

9.1

0

2

4

6

8

10

12

14

K (cm

/sec)

x 1

0-3

Percen

t P

oro

sit

y

Range of Porosities and Permeabilities

Dauphin

12.5mm

Cores SGC

Po

ro

sit

y

Perm

ea

bil

ity

Schyulkill

9.5 mm Mix

Lawrence

9.5 mm Mix

Cores SGC Cores SGC Cores SGC Cores SGC Cores SGC

York

12.5 mm MixBedford

9.5 mm Mix

Somerset

9.5 mm Mix

Po

ro

sit

y

Perm

ea

bil

ity


Figure 2

Range of porosity and permeability for the tested mixes

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0

Perm

eabi

lity,

cm

/sec

(10-3

)

Porosity, %

Dauphin County, SR 0300, 12.5 mm

Field Cores

SGC Specimens

Figure 3

Permeability versus porosity for the 12.5-mm mix of SR 0300

Dauphin County

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

0.0 2.0 4.0 6.0 8.0 10.0

Per

mea

bilit

y, c

m/s

ec (

10-3

)

Porosity, %

Schuylkill County, SR 0081, 9.5 mm

Field Cores

SGC Specimens

Figure 4


Schuylkill County

as the air void or porosity increases. For the Dauphin 12.5-mm mix, a

porosity level of approximately 8 percent for both field cores and

lab-compacted specimens seems to be a threshold value beyond which

permeability begins to increase drastically.

For the 9.5-mm mixes, the cores and lab-compacted specimens

could be considered impervious for porosity lower than 8 percent, as they

yielded permeability levels significantly lower than 1.25x10-3 cm/sec.

It was found that the thickness of lab-prepared specimens had a

major effect on measured permeability at porosity levels higher than

about 8 percent. In most cases, for porosity levels lower than 8 percent,

the permeability was sufficiently low (less than 1X10-3 cm/sec) and was

not highly affected by the thickness of the specimens.

WHAT DOES THIS ALL MEAN TO ME AS A PRACTITIONER? For most practical applications, as long as the in-place air voids

of 9.5-mm and 12.5-mm mixes remains under approximately 7.5 to 8

percent, permeability is not of concern. For cases where air voids exceed

this level, tests may be needed to ensure the compacted mix is

sufficiently impermeable. i.e. permeability does not exceed 1.25x10-3 cm/

sec for SGC specimens and 1.5x10-3 cm/sec for field cores. Specimens at

high air void content are of concern and permeability testing of such

specimens will be required to ensure permeability remains below the

recommended limits mentioned above. Checking permeability may be

especially important regarding mat density at the neighborhood of

longitudinal joint where density cannot be achieved to the same level as

the rest of the mat.

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

0.0 2.0 4.0 6.0 8.0 10.0

Per

mea

bili

ty,

cm/s

ec (

10-3

)

Porosity, %

Lawrence County, SR 0079, 9.5 mm

Field Cores

SGC Specimens

Figure 5


Lawrence County


0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0

Per

mea

bili

ty,

cm/s

ec (

10-3

)

Porosity, %

York County, SR 2007, 12.5 mm

Field Cores

SGC Specimens

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0

Per

mea

bili

ty,

cm/s

ec (

10-3

)

Porosity, %

Bedford County, SR 0026, 9.5 mm

Field Cores

SGC Specimens

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0

Per

mea

bilit

y, c

m/s

ec (

10-3

)

Porosity, %

Somerset County, SR 0281, 9.5 mm

Field Cores

SGC Specimens

Figure 6


York County

Figure 7


Bedford County

Figure 8


Somerset County


The Mid-Atlantic Quality Assurance Workshop is an annual event held each

year since 1967. The Workshop includes five breakout sessions devoted to

the latest information on highway materials in the areas of asphalt,

concrete, metals, maintenance, and soils and aggregates.

The states of Delaware, Maryland, New Jersey, Pennsylvania, Virginia, West

Virginia, and the District of Columbia make up the Mid-Atlantic QAW.

Sponsorship of the Workshop is rotated yearly, with the Pennsylvania

Department of Transportation (PennDOT) hosting the 2011 meeting, which

is to be held February 9-11, 2011. The meeting is open to anyone

interested in highway construction materials including government

transportation employees, contractors, producers and suppliers. Go to

www.midatlanticqaw.com for complete details and registration instructions.

The Mid-Atlantic Quality Assurance Workshop is an annual event held each

year since 1967. The Workshop includes five breakout sessions devoted to

the latest information on highway materials in the areas of asphalt,

concrete, metals, maintenance, and soils and aggregates.

The states of Delaware, Maryland, New Jersey, Pennsylvania, Virginia, West

Virginia, and the District of Columbia make up the Mid-Atlantic QAW.

Sponsorship of the Workshop is rotated yearly, with the Pennsylvania

Department of Transportation (PennDOT) hosting the 2011 meeting, which

is to be held February 9-11, 2011. The meeting is open to anyone

interested in highway construction materials including government

transportation employees, contractors, producers and suppliers. Go to

www.midatlanticqaw.com for complete details and registration instructions.

Consolidated Procedure—Pennsylvania Department of Transportation / Department of General Services

Zone 1

Districts 3-6 & 8 Zone 2

Districts 2 & 9 Zone 3

Districts 1, 10-12

Material Placed In: English Units Metric Units English Units Metric Units English Units Metric Units

December 2010 476.00 525.00 476.00 525.00 476.00 525.00

November 2010 471.00 519.00 478.00 527.00 485.00 535.00

October 2010 471.00 519.00 479.00 528.00 487.00 537.00

September 2010 471.00 519.00 478.00 527.00 485.00 535.00

August 2010 474.00 522.00 470.00 518.00 466.00 514.00

July 2010 481.00 530.00 485.50 535.00 490.00 540.00

June 2010 493.00 543.00 496.50 547.00 500.00 551.00

May 2010 508.00 560.00 510.00 562.00 512.00 564.00

April 2010 506.00 558.00 506.50 558.50 507.00 559.00

March 2010 494.00 545.00 500.50 552.00 507.00 559.00

February 2010 475.00 524.00 487.50 537.50 500.00 551.00

January 2010 455.00 502.00 455.00 502.00 455.00 502.00

Documents

PA’s New Joint Density Incentive/ By: Garth D. Bridenbaugh ... · materials costs. The research conducted during NCHRP Report 452 (McDaniels et al., 2001), and later adopted by