AASHTO Executive Director John Horsley joined Senate Environment and Public Works Committee Chairwoman Barbara Boxer, D-CA, in a conference call with reporters last Wednesday to stress the importance of the Senate passing a job-creation bill this month that contains an extension of surface transportation authorization through Dec. 31 and a deposit of about $20 billion into the Highway Trust Fund to keep it solvent.

During the call Horsley said "If an extension is not passed by Feb. 28, the federal highway program would be cut by $12 billion for the balance of this fiscal year.  If an extension is passed, the baseline for the program will be restored from $30 billion back up to $42 billion."

Horsley added that extending transportation authorization, currently set to expire Feb. 28, for 10 more months would ensure the preservation of thousands of jobs in the construction sector.  State transportation departments have been operating under three short-term extensions of their federal funding since Sept. 30 of last year, when the 2005 transportation authorization law known as "SAFETEA-LU" expired.

"Managing programs month to month doesn't work for states," Horsley said. "To build what the country needs, we need certainty so we can issue long-term contracts."

Boxer cautioned that the Highway Trust Fund will again run short of money this summer if action is not taken to deposit General Fund revenue owed to the trust fund for interest accrued since 1998.

"If we don't have that transfer, and that's why this bill is so crucial, then starting in June -- and certainly by August -- the Highway Trust Fund will be out of funds," Boxer said. "This extension provides states with the certainty they need to make decisions and carry out their plans."

The Senate is expected to hold a cloture vote Monday evening on an amendment to HR 2847, the Jobs for Main Street Act, which the House of Representatives approved in December.  The amendment, offered by Senate Majority Leader Harry Reid, D-NV, is dubbed "HIRE" for the Hiring Incentives to Restore Employment Act.  It would extend authorization through Dec. 31 and provide for more issuance of Build America Bonds by states and localities.  The bond program was created by last year's American Recovery and Reinvestment Act and and thus far has been used to subsidize issuance of $65 billion in infrastructure bonds, $17 billion of which have gone toward transportation projects.

During Wednesday's conference call, Boxer told reporters that Senate leaders will act on more job-creation measures later this year, including additional infrastructure funding. She said Reid's amendment to be voted on Monday is the first of several slimmed-down job-creation packages designed to attract bipartisan support. However, Capitol Hill media reported this week that Republicans are raising concerns that depositing about $20 billion into the Highway Trust Fund will increase the nation's budget deficit and that other tax provisions were not included in the amendment.

On Friday, the APA of California joined NAPA and other transportation sector associations and their members in a significant Grassroots effort to support the Reid Amendment which could be voted on by the Senate this Wednesday, February 24.  The measure needs to pass the anticipated cloture vote on Monday before it can be considered on Wednesday.  Everyone is being encouraged to contact their Senators to encourage them to support the measure.

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CARB Symposium

Estimating Premature Deaths from Long-term Exposure to PM2.5

 

The California Air Resources Board (CARB) will host a symposium on the science behind the methodology used to estimate PM-related premature deaths in California.  CARB has invited scientists from academic institutions and government agencies to discuss the scientific findings regarding the association between PM2.5 exposure and premature death.  The morning session will consist of short presentations, and in the afternoon, the format will be a round table discussion among scientists on a number of specific issues, including criteria for selecting a concentration-response function for making estimates of PM2.5-related deaths in California, how uncertainties should be addressed, and whether we can differentiate the effects of PM2.5 from specific sources.  At the end of the morning and afternoon sessions there will be an opportunity for the public to ask questions about the scientific evidence discussed.

Additional information about the CARB symposium to examine the relationship between premature deaths and long-term exposure to PM2.5 is now available and can be found here.

Date:         February 26, 2010 (See CARB link above for webcast information)Time:        9:00 a.m. to 5:00 p.m.

Location:  Cal/EPA Headquarters Building

                Klamath Training Room

                1001 I Street - 2nd Floor

                Sacramento, CA

Agenda:   Click here for a copy of the Preliminary Agenda

If you have technical questions, please contact Dr. Linda Smith, Research Division, Air Resources Board, P.O. Box 2815, Sacramento, CA 95812-2815 (lsmith@arb.ca.gov), (916) 327-8225.  Updates on the symposium and the revised methodology will also be sent out via our electronic list serve. To subscribe, please enroll at http://www.arb.ca.gov/listserv/listserv_ind.php?listname=pm-mort.

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  APA Celebrates 10 Year Anniversary and New Campaign

Last week at the World of Asphalt, the Asphalt Pavement Alliance (APA) announced a new campaign in support of asphalt pavements.  The APA is a coalition of the National Asphalt Pavement Association (NAPA), the Asphalt Institute (AI) and the State Asphalt Pavement Associations (SAPA) which was formed in 2000 and celebrates its 10 year anniversary this year.

As a part of its announcement, the APA unveiled its new campaign which include a new website, a new tagline, new imagery, a comprehensive technical document and a policy white paper.  The new website (found at www.asphaltroads.org) will continue to be populated with new, up-to-date articles and publications on the benefits of using asphalt pavements..

The new tag line “America Rides on Us. Asphalt.” Has the perfect double meaning: Asphalt is the pavement material that carries most of the traffic in the U.S., plus it’s a material that Americans can rely on.  The new website will include new technical documents on a monthly basis, new advertising materials  and a variety of other informational and promotional materials that can be used to promote asphalt pavements.

To access the new policy statement, the Perpetual Pavement Synthesis and see the new look for the APA, go to the website by clicking here.                              (Return to Top) 

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Technical Corner

by Rita Leahy, APACA Technical Director

 

Warm Mix Asphalt ? Why?

 

The production and placement of HMA pavements has evolved over the last 130 years from hand mixing and manual placement with rakes and shovels to computerized plants feeding automated remixing, placement, and compaction equipment that track location and material quality.  During this period, we’ve learned that temperature control is crucial to aggregate coating, mix stability during production and transport, ease of placement, compaction, and ultimately the performance of the pavement.  During construction, the temperature must be high enough to ensure the workability of the mix and yet below the temperature at which drain-down and excessive binder hardening occur.

 

New Materials and More Stringent Specifications

 

Today’s performance requirements often dictate the use of polymer-modified binders, more angular aggregate and higher levels of in-place density.  Mixes made with polymer-modified binders are sometimes more difficult “to work” than mixes made with unmodified asphalts.  Not surprisingly, a common cure for this lack of workability is to raise production and placement temperatures.

For high-volume surface course mixes, greater aggregate angularity is often specified.  The use of angular aggregate increases the internal friction of the material, which in turn increases the force, required to mix and place it, especially in coarse gradations.  Again, the answer to overcome this reduced workability is often increased temperature in an attempt to reduce the viscosity of the binder and improve the “flow” of the mix.

Along with material requirements that reduce the workability of HMA are higher in-place density specifications.  Density is used not only for acceptance and pay purposes, but also as a measure of pavement quality for dense- and gap-graded HMA.  Higher levels of density are associated with lower permeability to air and water, improving performance of these mixes.  If a mix shows resistance to compaction the normal response is to raise the mix temperature to more easily compress it during construction.

Increasing production temperature to address these concerns is often times expedient but not effective.  For little or no improvement in workability, increasing the mix temperature often results in increased plant emissions and fumes at the paving site.

  

Environmental Factors

 

Current and impending regulations regarding emissions are making it more attractive to consider greater reductions in HMA production temperature.  While stack emissions have decreased significantly over the last 35 years due to improved pollution control features, further reductions in the emission of greenhouse gasses will likely be required in the future.  In addition, current state and local regulations are such that in some ozone non-attainment areas, hot-mix plants are sometimes required to curtail operations in daylight hours during certain times of the year when ozone formation is problematic.  

Working conditions in the production and placement of HMA are also important to the industry as improvements lead to an enhanced work environment, higher-quality work, and better employee retention.  Significant HMA temperature reduction would have two benefits for the workforce:  it would further reduce fumes in the vicinity of all paving workers and it would make for a cooler work environment.

Complaints of odor sometimes occur in plants located near residential areas.  While there is no scientific evidence that odors pose a threat to the surrounding community, such perceived annoyances can create community relations problems.  However, if production temperatures were drastically reduced, the production of odors sometimes associated with plant and paving operations could drop to an inconsequential level.

  

Next Week

 

Temperature reduction in the manufacture of asphalt mixes is highly desirable from a number of aspects.  Reduced fumes, emissions and energy consumption are important environmental reasons to continue pursuing the goal of temperature reduction.  There are important construction and performance advantages as well:  improved workability results in better compaction; lower production and placement temperatures may improve prospects for cold weather and nighttime paving; and lower temperatures will result in less binder aging and possibly better cracking resistance.  

According to the FHWA’s Matt Corrigan, there are 15 to 20 WMA technologies used in the US.  Next week we’ll discuss the general categories of WMA technologies:  organic additives or wax; chemical modifiers or surfactants; and foaming.

 

References:

 - NAPA, Quality Improvement Series 125, Warm-Mix Asphalt:  Best Practices, B Prowell and G Hurley

 - NAPA, An Introduction to Warm Mix Asphalt, D Newcomb

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February Meetings for Your Calendar

  

Section 39 Task Group (Industry Only) - This meeting will take place on February 24th beginning at 9:00 am and end at 12:00 noon.  The meeting will take place at the Skanska USA Civil West Training Center on Agua Mansa in Riverside, CA.  This group will be discussing Caltrans Setion 39 issues and proposed changes that may be necessary.

 

HMATG - This Joint Industry / Caltrans Task Group will be meeting on February 24th between 1:00 pm and 4:00 pm.  The meeting will take place at the Skanska USA Civil West Training Center on Agua Mansa in Riverside, CA.  This group will be preparing for the Rock Products Committee Meeing on Feb 25th and addressing issues of concern for the HMA idustry in California.

 

Rock Products Committee (Industry Only) - This meeting will take place on February 25 between 9:00 am and 12:00 noon.  The meeting will take place at the Skanska USA Civil West Training Center on Agua Mansa in Riverside, CA.

 

Rock Products Committee - This Joint Caltrans / Industry Committee will be meeting on Thursday, Feb 25th between 1:00 am and 4:00 pm.  The meeting will take place at the Skanska USA Civil West Training Center on Agua Mansa in Riverside, CA.

 

For questions, copies of tentative agenda's or other information, please contact the APA of California office at 949-855-6489.                                                     (Return to Top)

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Training Opportunities