Volume 42, Number 6
October 6, 2006
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Special Edition Issue... The Environment

California Brings Environmental Issues to Forefront
Device Streamlines Accelerated Load Testing, Saves State Money
Community Lightens Up, Cools Off with Concrete Pavement
Report Focuses on Incorporating Environment into Transportation Planning

In this issue ...

 Tech Corner

Next issue ...
Paving Costs--The Inside Story

 

California Brings Environmental Issues to Forefront
New Legislation Will Limit Cement, Asphalt Plant Operations
 
California Governor Arnold Schwarzenegger last week signed legislation aimed at reducing greenhouse gases.

Known as Assembly Bill (AB) 32, the legislation commits the state to reduce the emissions of carbon dioxide and other greenhouse gases by 25% by 2020.

The legislation authorizes the California Air Resources Board and other agencies to begin measuring greenhouse emissions from electric power plants, oil refineries, cement manufacturing plants, and others.

The initiative will employ market mechanisms-including emissions trading-to find the economically most-efficient ways to reduce global warming. Beginning in 2012, emitters will be assigned firm limits on the amounts of carbon dioxide they can release into the atmosphere.		  
 
Those caps will be gradually lowered to meet the 2020 target.

How This Affects the Concrete Pavement Industry		   California Governor Arnold Schwarzenegger this week signed legislation aimed at reducing greenhouse gases.  


Although the move has been hailed by some, there is strong concern about the negative effects of this bill, which may well prove to be a harbinger of bad news for the state.

In a letter to Governor Schwarzenegger, Jim Repman, President and CEO of the California Portland Cement Co., says, "AB 32 will hurt California's efforts to rebuild its crumbling infrastructure." He adds that AB 32 recognizes that regulatory obstacles may impede greenhouse gas (GHG) reductions, but fails to address any of these problems.

He also cautions, "California's population is forecast to grow by at least 21% between now and 2020, which will require more electricity and transportation. We must find a way to meet these needs."

He continues, "Corporate executives will have tough decisions when answering to their Boards of Directors about the viability and prudence of making significant new investments in California in many industries including cement manufacturing.

"What is equally as troubling is that the State's own Department of Transportation (Caltrans) is fighting the adoption of the ASTM standard for cement that was revised nationally in 2004. This change would allow us to increase cement production by 5% to meet demand with no increase in GHG.


"On one hand [with AB 32], we are being mandated to reduce GHG's and yet those mandating the same say but don't change what you are doing."

ACPA President and CEO Jerry Voigt, P.E., also commented on the legislation, saying, "Although we recognize the need for states to address environmental concerns, we are concerned anytime legislation works against business and industry.

"Our chief concern about this initiative is that it hampers members of our industry, as well as other suppliers to the transportation community," he said.

The long-range impact of AB-32 may be uncertain, but one thing is for sure: This legislation proves that environmental issues have the attention of a growing number of policymakers. This underscores the need for trade associations and members to work together to find a balanced approach to addressing environmental needs.

High Profile Event

Considered by some to be a model for legislation in other states, the signing ceremony also was notable because of the scale, as well as the surrounding pomp and circumstance. According to the SAN FRANCISCO CHRONICLE, the signing ceremony also "gave Schwarzenegger a platform to display his environmental credentials weeks before voters decide whether to give him another term."

The ceremony included a live satellite video message of congratulations from British Prime Minister Tony Blair, as well a message read on behalf of Japan's outgoing Prime Minister Junichiro Koizumi. Also joining Schwarzenegger onstage were New York Gov. George Pataki (R), San Francisco Mayor Gavin Newsom (D), as well as the bill's cosponsors, California Assembly Speaker Fabian Nunez
(D-Los Angeles) and Assemblywoman Fran Pavley (D-Agoura Hills). (Sources: KXTV (ABC), San Francisco; San Francisco Chronicle; and reports by ACPA's CONCRETE PAVEMENT PROGRESS staff.)


NEWS and VIEWS
What is your opinion of AB-32?

The editors of CONCRETE PAVEMENT PROGRESS are interested in your views and opinions about current topics of importance to the transportation community.

Please click here to take a brief, five-question survey on California's Assembly Bill-32. (See related story above.)

Thank you for taking the time to participate in this brief questionnaire. Your responses, whether anonymous or not, will be published in a future issue of ACPA's CONCRETE PAVEMENT PROGRESS.

Be sure to include your contact information to be eligible for a free prize drawing. Note that we will only publish your name and other information if you consent to it.

Questions? Contact Erin McKnight at 847-966-2272.

 

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Device Streamlines
Accelerated Load Testing, Saves State Money
by Mark B. Snyder, PhD, P.E.

Adjustments to a load-testing device have made building and testing new and experimental highway pavement designs and materials cheaper and faster in Minnesota.

In 1993, the Minnesota Department of Transportation (MnDOT) commissioned the University of Minnesota to construct a laboratory-based accelerated load test facility for pavements. This facility, dubbed "Minnesota Accelerated Loading Facility" or "Minne-ALF," was designed to be useful for a wide variety of structural and environmental response studies for both asphalt and concrete pavements.
The original Minne-ALF was reconfigured into the above testing facility, Minne-ALF 2, to simulate wheel loads moving at 40 mph or higher without mobilizing a heavy mass.
It safely simulates the linear passage of wheel loads moving at speeds of 40 mph or more without mobilizing a heavy mass.


MnDOT has used the results of Minne-ALF tests to approve alternate dowel materials for high-performance concrete pavements and for evaluating different retrofit dowel construction parameters.

This device is now available for contract research studies. The Minne-ALF can be configured in many different ways to address various test parameters. Load, deflection and other instrumentation data are collected automatically at user-specified intervals.

The Minne-ALF is currently being reconfigured to provide direct control over joint widths for tests of joints with misaligned dowels.

It can also be used to investigate a wide range of other pavement design, rehabilitation and behavior issues for both concrete and asphalt pavements, including:

• Curl and warp studies;
• Effects of increased load limits and modified truck gear configurations;
• "Optimization" of dowel load transfer systems (i.e., material selection, dowel size, shape and location);
• Foundation pumping and drainage studies;
• Asphalt mix stability and deformation studies;and
• Load equivalency studies.

Some of these applications would require further test stand modifications. The Minne-ALF is now available for contract research activities. Inquiries should be directed to Dr. Lev Khazanovich, Associate Professor-Civil Engineering, University of Minnesota.

More complete descriptions of the test stand and results to date are available online by clicking here.

 
Mark Snyder is an independent engineering consultant in the Pittsburgh, PA area. A former college professor, Snyder has been involved in concrete pavement-related research for more than 25 years. He also served as Executive Director of the Concrete Paving Association of Minnesota for four years. He is currently working as an independent engineering consultant in the Pittsburgh, PA area and is a registered professional engineer in Illinois, Minnesota and Pennsylvania. Snyder can be reached by e-mail or at 412-979-8332.

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Community Lightens Up, Cools off with Concrete Pavement

When residents of the Rio Verde Community Association (RVCA) needed to repave their parking lot, they turned to a clean, bright concrete pavement to solve the problems of distressed asphalt.

Rio Verde is a beautiful golf course community located 30 miles northeast of Phoenix with spectacular views. But, residents complained about the heat generated from asphalt streets. Residents typically would walk on the concrete golf-cart paths, observing that it was much cooler than asphalt.
 

 

Before and After... These photos show the heat levels generated by an asphalt pavement (left) versus the cooler effects of the concrete overlay placed over it (right).
 

In fact, concrete can be up to 8 to 15°F cooler than asphalt in hot weather, according to Larry Scofield, P.E., Director of Environmental Technology for the American Concrete Pavement Association.

Aesthetically, the community center's parking lot was old, cracked, and was showing signs of its age and poor condition. Because of the pavement condition, water was ponding in some areas of the parking lot. Also, some residents complained about tracking black asphalt oil from the parking lot and streets into their driveways, garages, and homes. Asphalt oil is used to seal fresh asphalt pavement, and then again repeatedly to maintain and repair cracks and other distresses that occur over time.

With the challenges presented by asphalt, it was time for change.

A local engineer conducted a 30-year life cycle cost comparison and concluded that the community could save $80,000 by resurfacing the distressed asphalt with long-lasting concrete pavement.

"The life of the asphalt in our parking lot was past its prime, and we needed to remove and replace it," said Doris Findling, Executive Director, RVCA. "Normally we would have repaved with asphalt, but the Board of Directors was shown how an ultrathin concrete pavement could provide additional benefits. The board voted unanimously on the concrete option."

A 3-in. overlay (sometimes called ultra-thin whitetopping) was placed over the distressed asphalt. This tried and tested technology dates to early 1988, when thin sections of concrete were placed over distressed asphalt in experimental projects in Kentucky, Iowa, Tennessee, and many other states. Since these early test sections were placed, more than 1 million square yards of ultra-thin whitetopping have been placed nationally. These pavements are estimated to provide two to three times the life of similar asphalt overlays.

One of the secrets to the durability of thin concrete overlays is close "joint spacings." Technicians cut the placed concrete into small panels - in this case, 3 ft. by 3 ft. sections - to control cracking that would otherwise weaken concrete.

Typically, in projects of this nature, a like amount of the underlying asphalt would be milled off prior to the placement of the concrete. In this case, however, the concrete was placed directly over the top of the old pavement. Remarkably, concrete has a strong affinity for distressed asphalt, which forms a tenacious bond to the concrete and thereby stabilizes the entire substrate. Another key to success was the skills and cooperation among the various team members.

"One of the major problems with the existing parking lot was standing water in the southeast corner after rainstorms," said Paul Ochs, Co-Owner of RGG United Constructors Inc., Glendale, Ariz. "Working to ensure correct drainage made this project challenging."

"Survey shots were taken on 15-ft intervals and grade adjustments were made to ensure correct flow," Ochs said. "However, working together with the various stakeholders in a partnering relationship produced a successful project that has met all of its intended purposes."

The addition of alkali-resistant glass fibers acted as a bonding agent to the cement paste to absorb the stresses until the concrete has gained sufficient strength, according to James Patterson, National Sales Manager, Saint-Gobain Specialty Reinforcements Group, Peoria, Ariz.

"The new pavement looks great," added Findling. "Residents have commented on the pleasing aesthetics of it and the lack of tracking. We're looking forward to the potential for no maintenance costs in the near future."

When the parking lot was completed, the Rio Verde Community Association's board of directors voted to extend the contract to pave a short city street, cul de sac, and curb section with concrete. A number of homeowners in the community also have replaced their asphalt driveways with concrete, in large part because of the aesthetically pleasing and durable parking lot.

Beyond the Rio Verde project, the concrete overlay provides an environmentally-friendly, cooler surface for streets and highways.

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Report Focuses on Incorporating
Environment into Transportation Planning

A recent report released by the Transportation Research Board presents eight technologies for agencies to consider environmental concerns when making transportation decisions.

Research Results Digest 304 presents the results of work conducted in the second and final phase of the National Cooperative Highway Research Program (NCHRP) Project 25-22, "Technologies to Improve Consideration of Environmental Concerns in Transportation Decisions. The report identifies, critiques, and showcases the current and emerging technologies that support the integration of environmental considerations in transportation planning, design, construction, maintenance and operations.

State DOT's can then take the technologies to reduce project development time, reduce costs, and enhance environmental quality.

After considering 70 applications, the research team used accompanying documentation and the help of expert panels to determine the top eight technologies:

• Interactive Regional Scenario Analysis
• Integrated Aerial Data Collection
• Road and Rail Alignment Optimization
• Web-Based Environmental Screening		 ...... • NEPA Document Preparation and Review Expert System
• Restricted Activity Zone Mapping
• Electronic Asset Management System
• Life Cycle E-Engineering

Click here to read the report, including full descriptions of the technologies.


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Frequency Content Important to Consider
in Tire/Pavement Noise Analysis

While all regulations and most discussions involve only the overall noise levels, frequency content is a very important consideration in regards to tire-pavement noise annoyance.

From the worst-case random transverse tined surface to the ground section in testing in Arizona, the difference is almost 9 dBa.

The one-third octave band spectra for the four surfaces show that most of the difference between the tined and ground surfaces occurs at frequencies below about 1,600 Hertz.

 This represents the range of overall A-weighted noise levels for selected Arizona textures. From the worst-case random transverse tined surface to the ground section, the reduction is almost 9 dB.


Another example of the importance of frequency in regards to noise annoyance can be found in a California example on a freeway segment in Santa Clara County (SCL 85).

The newly opened freeway had been constructed using Caltrans standard longitudinal tining. However, motivated by public outcry regarding pavement noise upon opening of the freeway, the local transportation commission funded a short, experimental grooving and grinding test section.

The test section, located in the city of Saratoga, was constructed to determine if modifying the pavement surface could lower overall traffic noise levels. Initial reaction from the community was quite favorable after the grinding and texturing was complete.

To quantify this effect, sound intensity measurements were made comparing the ground pavement to that of the original tining. The results produced two observations.

First, although the overall average difference between the two surface types was only slightly more than 2 dBa, the grinding produced more uniform noise levels with variations of 1 dBa or less for different ground sections. The original tined surface had variations ranging from 1 to more than 2 dBa. As a result, the worst to best reduction was more than 4 dB with a number of individual sections producing reductions on the order of 3 dBA.

The second observation was that the largest reductions on a one-third octave band basis were found in bands around 1,600 Hz. These frequencies are thought to be responsible for a higher frequency "presence," or sizzle sound, which can be noticeable in the community. So although there was not a dramatic difference in overall loudness (e.g. 2 dBA) the community considered it a positive improvement.

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ACPA Concrete Pavement Progress is published 12 times per year and covers current practices and case histories in the concrete pavement industry. ACPA Concrete Pavement Progress is distributed free of charge to public officials, ACPA members, executive committee, board of directors, and affiliated chapter/state paving associations.

All rights reserved. Copyright 2006 by the American Concrete Pavement Association. No portion of this publication may be reproduced mechanically or electronically without the expressed written permission of the American Concrete Pavement Association.
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Visit our website at http://www.pavement.com/		  
2006 Chairman, ACPA Board of Directors
Peter Deem, Holcim (US) Inc.
2005 Vice-Chairman, ACPA Board of Directors
Pat Nolan, Interstate Highway Const., Inc. (IHC)

ACPA President/CEO - Gerald F. Voigt, P.E.
Editor - Bill Davenport
Managing Editor - Erin McKnight