What in your bookcase? I posed this question to over 40 professionals in the asphalt industry. Their expertise spanned the full spectrum from liquid manufacturers, pavement engineers, equipment manufacturers, lab technicians, contractors, consultants and maintenance professionals from industry, agencies and academia.

The responses indicate that you do not have to spend a king ransom to equip yourself to handle the majority of the issues you will face as a practitioner, regardless of your particular focus area. What was also interesting is that the references may not just reside on your bookshelf ut today are as likely to be in your computer or on the web. Take a look at some of the most cited responses.

Your College Textbooks Have a Role
At the college level, most civil engineers receive only a modest exposure to asphalt materials and pavement design methods, yet additional exposure and experience is readily found in graduate work at select universities. So, it is helpful for practitioners to build a reference library.

Not surprising, college textbooks often remain on our shelves for years and can provide quick answers to common questions. E.J. Yoder and M.W. Witczak抯 Principles of Pavement Design, while out of print, is one such textbook you will find on many bookshelves of seasoned practitioners. It was often mentioned in our survey.

A useful educational website reference is Pavement Interactive, available online at http://pavementinteractive.org. Yet another reference is the Virtual Superpave Laboratory used for training engineering students, developed by the University of Washington for the National Asphalt Pavement Association (NAPA).

Materials and Standards
The Aggregate Handbook, published by the National Stone, Sand and Gravel Association provides a useful reference for designers and contractors alike. This book was cited by many in our survey. The Asphalt Institute and the Asphalt Emulsion Manufacturers Association teamed up to write The Basic Asphalt Emulsion Manual, available from either association. It is an essential reference for those working with emulsions. You have to include two more essentials: the Institute抯 MS-5, Introduction to Asphalt and MS-6, Asphalt Pocketbook of Useful Information. Now you have a solid background of reference materials covering all the basics of materials.

No collection of references could be considered complete without the design standards themselves and there are several sources to consult in this department. Start with the ASTM and AASHTO Standards and Test Methods. These are updated frequently, and can be expensive, so you will often only find a single set in your office. You will want to ensure you have the most recent version because they do change.

Pavement Thickness and Mix Design
Software tools are a tremendous help in this area and several experts referenced the Asphalt Institute抯 SW-1 and SW-2 for both thickness design and mix design capability respectively. Additionally, the Asphalt Pavement Alliance distributes the recently updated PerRoad, free software which enables designers to design a Perpetual Pavement. This software bases its design methodology on limiting strain criteria in the bottom layer of the pavement structure. 

Maintenance Mainstays
Likewise, the Asphalt Recycling and Reclaiming Association publishes the Basic Asphalt Recycling Manual, known as the BARM in the industry. It is packed with useful information.

The International Slurry Seal Association produces a number of bulletins on slurry sealing and microsurfacing which you will find very helpful with pavement maintenance.

Speaking of pavement maintenance梐nd this segment of the industry has received renewed attention lately梑e sure to investigate the pavement preservation materials available through the Federal Highway Administration. You can find these references via the FHWA website, www.fhwa.dot.gov/preservation/. In particular, the compendium document was often cited by our panel of experts.

Starting in the late 1980s, the largest Federal effort in our history concerning pavement performance began. Over its 20 year life, data was collected on pavements throughout the United States and 15 other countries. That data, representing a wide variety of pavement conditions, climate, traffic volume and loads, was collected to enable engineers to design better, longer-lasting pavement structures.

As part of the Strategic Highway Research Program, this particular effort was titled the Long-Term Pavement Performance (LTPP) program. An essential reference from the study is the LTPP Distress Identification Manual for the Long-Term Pavement Performance Program (Fourth Revised Edition) and is officially numbered FHWA-RD-03-031.

In that same vein, there are several helpful references published by the National Cooperative Highway Research Program. A great place to start is their website, www.trb.org/crp/nchrp/nchrp.asp.

Is Construction or QA/QC Your Game?

If your focus is on construction of asphalt pavements, then the Asphalt Institute抯 MS-22, Construction of Hot Mix Asphalt Pavements is a handy reference. It is also available in a Spanish text version. The National Center for Asphalt Technology (NCAT) textbook entitled Hot Mix Asphalt Materials, Mixture Design and Construction was mentioned by several of our survey respondents. Additionally, there are a variety of technical papers available from Astec Industries and others, which offer practical guides for all facets of plant operations and pavement construction. Go to their websites to obtain those documents.

Transportation Research Board (TRB) publishes their Hot-Mix Asphalt Paving Handbook and it is a useful reference. Others mentioned TRB publication entitled Effects of Subsurface Drainage on Performance of Asphalt and Concrete Pavements. TRB also publishes Research Records any of which cover the asphalt industry in some form. And, if you have not been to TRB annual meeting held in Washington, DC, in January of each year, add this to your professional development ust do?list.

Do not forget safety. A few years ago, with the assistance of its member companies, the Asphalt Institute produced an essential safety video and workbook (VA-26)梐 must for everyone working with hot asphalt. This video is a great training aid for new workers or as a seasonal et your head in the game?update.

A Historical Perspective
After you have accumulated a list of essential references, your attention should turn to historical perspectives. You cannot go wrong by having an entire collection of the Association of Asphalt Paving Technologist (AAPT) Journals. Volume 76 was published this year and many back issues are available on CD media from AAPT. If you ask around a little, you can often find a retiring practitioner who will give their set to you.

Another historical reference is Herbert Abraham publication, Asphalt and Allied Substances. While out of print, it is a useful and historical reference. Other historical publications focusing on the paving industry can be found in the NAPA bookstore.

MS-4, The Asphalt Handbook
Many cited the Asphalt Institute publications and software in their top picks. While the Institute publishes over 100 titles, those mentioned most often are listed in the sidebar to this article. Topping the list is AI venerable MS-4, The Asphalt Handbook,. Now undergoing a major revision, it is scheduled for release in the fall of 2007.

For anyone desiring a leading reference that covers a multitude of subjects from design to construction, pavement management and maintenance, MS-4 is the book for you. It is truly a desktop reference for the industry.

Interestingly, we know of several individuals who have collected every version of MS-4 since it was first published over 70 years ago ut that is another story.

And You?
What about you? Now that your bookshelf is set up, you have to improve your bandwidth and depth of knowledge. Professional associations are a great place to start. Those groups include AAPT, the Canadian Technical Asphalt Association, which like AAPT publishes its own papers in its annual Proceedings, and the newly formed European Asphalt Technology Association, which provides a similar venue in Europe. (See below for more information on these and other professional groups.)

There more! (Lots more!)
We have amassed a great deal of input from our survey of industry professionals ay too much to include here. Continue to watch www.asphaltmagazine.com as we explore this interesting topic further, and visit the site anytime to see the latest news in our industry.

In our industry, you need to build a reference library for your own use and get involved in some way in a professional or trade association to build on what you have already learned. Our industry is undergoing remarkable change. Materials are changing, design procedures are changing, and construction techniques are changing, all adding better performance and value to the finished product. Learning is truly a life-long process.

Get started!

Peter T. Grass, P.E., is president of the Asphalt Institute headquartered in Lexington, Kentucky. Now in its 88th year, the Asphalt Institute serves the needs of asphalt manufacturers and suppliers worldwide.

In addition to the various trade associations for companies, there are several individual based technical organizations which you should seriously consider joining as part of your professional journey.

Association of Asphalt Paving Technologists (AAPT)
Formed in 1924, AAPT has an annual meeting held in the Spring of each year for its approximately 800 members. Its first Journal was published in 1928. Their next meeting is scheduled for April 27-30, 2008 in Philadelphia, Pennsylvania.
Contact: Executive Secretary Eileen Soler at aapt@qwest.net or
phone (651) 293-9188
www.asphalttechnology.org

Canadian Technical Asphalt Association (CTAA)
Organized in 1955, CTAA has an annual conference with approximately 350 attendees at the four-day event. CTAA next meeting is in Niagara Falls, Canada; November 18-21, 2007.
Contact: admin@ctaa.ca or
phone (250) 361-9187
www.ctaa.ca

European Asphalt Technology Association (EATA)
EATA was established in 2004 by the Nottingham Centre for Pavement Engineering as part of its 50th anniversary. Its next meeting will be in 2008-2009 in France.
Contact: Sheila Provost at Sheila.provost@nottingham.ac.uk
phone (0115 846 6046)
A provisional web site (www.nottingham.ac.uk/eata) provides information as it becomes available.

International Society for Asphalt Pavements (ISAP)
ISAP grew from a series of widely acclaimed technical conferences which began at the University of Michigan, Ann Arbor, in 1962. ISAP was formally established in 1987. Their next symposium is planned for Zurich, Switzerland, in 2008.
Contact: Membership Secretary Eileen Soler at (651) 293-9188 or
Secretary@asphalt.org
www.asphalt.org

Essential Asphalt Institute Publications
There are a lot of reference materials out there. Sort the wheat from the chaff and start here ith these engineer bookshelf essentials from the Asphalt Institute. They are all available today at the Asphalt Institute online store.

MS-1 Thickness Design ?Asphalt Pavements for Highways and Streets
MS-2 Mix Design Methods for Asphalt Concrete and Other Hot Mix Types
MS-4 The Asphalt Handbook
MS-16 Asphalt in Pavement Maintenance
MS-17 Asphalt Overlays for Highway and Street Rehabilitation
MS-19 The Basic Asphalt Emulsion Manual
MS-22 Construction of Hot Mix Asphalt Pavements
SW-1 Asphalt Pavement Thickness Design Software CD
SP-1 Superpave Performance Graded Asphalt Binder Specification and Testing
SP-2 Superpave Mix Design