Newsletter

(Courtesy of AASHTO)

California Proposition 23

As previously reported, California Proposition 23 suspends State laws requiring reduced greenhouse gas emissions that cause global warming, until California's unemployment rate drops to 5.5 percent or less for four consecutive quarters. Further, it requires the State to abandon implementation of comprehensive greenhouse-gas-reduction programs that include increased renewable energy and cleaner fuel requirements, and mandatory emission reporting and fee requirements until the suspension is lifted.

As written, Assembly Bill 32, "The Global Warming Solutions Act of 2006," was intended to protect California from human caused global warming. Many feel that whether global warming is in fact caused by humans or by natural processes, AB 32 is ineffective and counterproductive, massively costly to businesses and families, and will increase our state deficit and/or cut services including those related to public health and environmental protection.

Economists estimate if nothing is done AB 32 will:

Cost California up to 1.1 million jobs
Cost the average family $3,857 a year in greatly increased expenses for housing, transportation, food and energy
Cost $49,691 per small business
Result in a total loss of output of $182.649 billion
Devastate budgets of California social services agencies through massive losses in tax revenue

After a recent California Air Resources Board (CARB) meeting to hear testimony concerning the economic impact of implemting AB 32, Board Member Ron Roberts (San Diego County Supervisor) states that the economic impact of implemetation would be very significant and cost California jobs. To see Supervisor Roberts comments please click here.

If you would like to join in the efforts to support Proposition 23 and suspend the implementation of AB 32 please click here.

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Asphalt Pavement - The Green Pavement Alternative

Asphalt is the sustainable material for constructing pavements. From the production of the paving material, to the placement of the pavement on the road, to rehabilitation, through recycling, asphalt pavements minimize impact on the environment. Low consumption of energy for production and construction, low emission of greenhouse gases, and conservation of natural resources help to make asphalt the environmental pavement of choice.

Energy and Recycling

1. Less energy consumed in building pavements
Asphalt pavements require about 20 percent less energy to produce and construct than other pavements.¹

2. Less energy consumed by the traveling public
Congestion leads to unnecessary consumption of fuel and production of emissions. Reducing congestion by constructing asphalt pavements just makes sense. Asphalt pavements are faster to construct and rehabilitate. And, a new or newly rehabilitated asphalt pavement can be opened to traffic as soon as it has been compacted and cooled. There is no question of waiting for days or weeks for the material to cure.

3. America’s leading recycler
The asphalt industry reclaims about 100 million tons of its own product every year, and reuses or recycles about 95 million tons. This makes it America’s number one recycler.

Other materials are routinely recycled into asphalt pavements. Some of the most common are rubber from used tires, glass, blast furnace slag, and asphalt roofing shingles.

For more information on the sustainability of asphalt pavement and the reason it should be your first choice for your pavement decisions, visit the Asphalt Pavement alliance website @ www.asphaltroads.org or click here.

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Technical Corner

by Rita B Leahy, APACA Technical Director

The Last Bowl of Alphabet Soup: NDT for QA of HMA

Recall from the past two weeks we’ve been reviewing the background information on non-destructive testing (NDT) technologies and field studies undertaken in the National Cooperative Highway Research Program (NCHRP) Project 10-65, the purpose of which was to identify NDT technologies ready and appropriate for implementation in routine, practical QC/QA operations.

The NDT technologies included in the field study for HMA included the following:

- Deflection Based Technologies

FWD (falling weight deflectometer)

WD (light weight deflectometer)

- Ground Penetrating Radar (GPR)

- Seismic Pavement Analyzer(SPA)

- Non-Nuclear Electric Gauges

PQI (pavement quality indicator)

PaveTracker

So, let’s fast-forward to the conclusions and recommendations.

Conclusions

The PSPA (portable seismic pavement analyzer) is a self-contained NDT device that can be readily incorporated into a QA program for both control and acceptance testing of HMA. An advantage of this technology is that the device can be calibrated to the specific materials being tested during the mix design stage. This calibration procedure allows the PSPA to be used to detect volumetric, as well as physical changes in the materials during construction. In short, the PSPA can be used in day-to-day operations to assist contractor and agency personnel in judging construction and materials quality by itself or in tandem with other geophysical and/or ground truth sampling programs.

However, the PSPA does have some limitations regarding full-scale use in QA programs. Use of the PSPA should be delayed after rolling to allow the mix to cool. The researchers recommended a 24-hour delay in testing. Obviously, this time restriction is considered a disadvantage for use in QA programs.

A measure of the HMA density or air voids is also required in judging the acceptability of the modulus value or durability of the mix. The two devices that deserve further evaluation include the GPR and non-nuclear density gauges (PQI and PaveTracker). The GPR provides full coverage in a short period of time.

The non-nuclear density gauges are also well suited for QA because they can be readily incorporated into control programs. Some contractors are already using the non-nuclear density gauges in controlling the compaction operation. This technology was also used to identify non-uniformity at a reasonable rate and can be used to identify tender mixes and the effects of rolling in the temperature sensitive zone.

Variations in water have a definite effect on the HMA density measured with the PQI. The manufacturer’s recommendation is to measure the density immediately after compaction, prior to allowing any traffic on the HMA surface. This type of time restriction is considered a disadvantage to the use of the PQI in a day-to-day practical QA program. The other non-nuclear density gauges (PaveTracker) was not sensitivity to moisture in the HMA.

Use of the single-antenna GPR technology, even with mix-specific calibration, requires assumptions of volumetric properties that may vary along a project. Use of the multi-antenna method is expected to improve on the measurement of the volumetric properties and identification of areas of non-uniformity or areas with deficiencies. Thus, the GPR is suggested for continued evaluation, especially with the multiple antenna system, which is a proprietary analysis system. The proprietary system needs additional validation prior to full-scale implementation into a QA program.

The FWD is not suggested for use in QA programs for two reasons: 1) because of the variability in back-calculated modulus values generated from the field data; and 2) because the field deflection measurements are influenced by the thickness and strength of the underlying materials.

Recommendations

The research team’s recommendations are based on the evaluation of NDT devices for immediate and practical use in QA programs.

The PSPA is the device suitable for use with HMA. The PaveTracker can be used in establishing and confirming the rolling pattern for HMA. Other NDT devices may provide useful data for pavement and materials testing purposes. Each has its own benefits and advantages for evaluating and designing pavements.

The IC (intelligent compaction) or instrumented rollers can be valuable to a contractor in terms of controlling the compaction operation. The rollers that operated without problems were used on too few projects to suggest their immediate inclusion in QA programs. Nonetheless, they can assist the contractor in optimizing the compaction of the material. The disadvantage for HMA is related to the mat temperature: decreases in temperature will cause the stiffness of the mat to increase. Thus, other devices still need to be used with the IC rollers for control. The use of IC rollers for acceptance is not suggested at this time.

Research with the multi-antenna GPR device and proprietary data interpretation system should be validated in future studies. This system definitely shows promise in providing the volumetric properties for HMA. The data can be collected at highway speeds, and the proprietary data interpretation system can provide results on a real-time basis. The disadvantage of this system is that it also needs field cores to calibrate the method to project specific conditions.

References:

H Von Quintus, C Rao, R Minchin, S Nazarian, K Maser and B Prowell, NCHRP Report 626, NDT Technology for Quality Assurance of HMA Pavement Construction, Transportation Research Board, Washington, DC, 2009.

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Tell Your Member of Congress to Make Highway Bill a Priority!

10 months have passed since the expiration of SAFETEA-LU and it appears Congress will not take action on a multi-year reauthorization bill before the mid-term elections in November. As state and local governments slash highway spending, and the private markets remain soft, unemployment in the transportation construction industry hovers at 20%. Stimulus funding will begin to wane in the fourth quarter of 2010 casting an air of uncertainty over the 2011 highway market.

Without predictable, multi-year highway funding at the federal level, state transportation departments will not start new projects and contractors will not be able to plan beyond the short-term extensions. The program is currently funded by a short-term extension lasting through December 2010. Over the past two years, the Highway Trust Fund has had to “borrow” $36 billion from general fund revenues, undermining the user-fee principle and the public’s trust. Without additional revenues, we are facing a 30-50% cut in the federal program as early as 2012.

The APA of California is cooperating with the National Asphalt Pavement Association (NAPA) in a "Grass Roots" effort to meet with our California Legislators while they are in California on vacation from their Washington DC offices. We will be attempting to create an “outside-the-beltway” movement to make the Highway Bill a priority in Washington. We will be working with members of the Transportation Construction Coalition and the Americans for Transportation Mobility Coalition to launch this campaign. It is important that you meet with your representatives - Congress will not act on a reauthorization bill unless they hear from you.

The following information will assist you in setting up the meetings:

- To identify and contact your Member of Congress, click here.

- Information about the pending highway funding crisis, click here.

- Talking points on why Congress needs to take action on highway legislation

- Instructions on how to arrange meetings and questions to ask

- Congressional meeting feedback form.

- TRIP state-by-state fact sheets.

- Impacts of recurring delays and extensions

- Highway Construction Materials Group White Paper.

- Report on jobs in the Asphalt Pavement Industry

We are encouraging everyone to contact their representatives and let them know just how important the passage of significant, well funded, multi-year highway funding bill is to you and your business!

If you have any questions, please contact the APA of California office at 949-855-6489.

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Training Opportunities

Webinar: New Non-Destructive Testing Technologies for HMA Quality Assurance

Date: Thursday August 5, 2010

Time: 12:30pm - to 2:00pm EASTERN Daylight Time

Non-destructive testing (NDT) methods have shown potential for use in the quality control and acceptance of flexible pavement construction. This webinar will explore the application of nondestructive testing (NDT) technologies in the quality assurance of hot-mix asphalt (HMA) pavement construction.

Fee:

No fee for current Chairs of TRB Standing Committees, Sections or Groups, employees of TRB Sponsors. All others $99.

Registration: https://www1.gotomeeting.com/register/487926817