|FHWA > Engineering > Pavement > Asphalt > Hot Mix Asphalt for the Undergraduate|
In the United States in 1988 there were approximately 4 million miles of roads of which 2.3 million were surfaced with asphalt or concrete. The balance of the roads were surfaced with either gravel, stone, or soil (1.3 million miles), or they were non-surfaced (0.4 million miles). Of the hard surfaced roads, approximately 96 percent of the 2 trillion annual vehicle miles of travel occurred on these hard surfaced roads.
In 1998, expenditures for highways were over $68 billion at all levels of government. Since 1981, these expenditures have grown at an annual rate of over $3.5 billion. The $68 billion spent in 1988 included $32 billion for capital outlays and $20 billion on maintenance activities.
During 1988, the amount of HMA produced and placed in the U. S. was estimated to be 500 million tonnes valued at some $10.5 billion. The HMA industry directly employs some 300,000 people and indirectly accounts for an additional 600,000 jobs. When combined with the state and federal employees associated with the construction and maintenance of asphalt surfaced roads, the industry today has a significant impact on the economic vitality of the nation.
Additionally, many engineers and technicians from all sectors of the asphalt business who entered the work force during the early days of the construction of the interstate system are reaching the end of their careers. These people must be replaced by engineers and technicians who are knowledgeable of asphalt materials and their proper use to successfully rebuild the highway sector of the transportation infrastructure.
A major concern of Governmental and Industry representatives throughout the country involves extending training efforts to a wider universe of asphalt pavement technologists. To address these concerns, Colleges and Universities with civil engineering programs have been identified as key components in the overall implementation efforts due to their role in developing the workforce force the next generation. The Federal Highway Administration through a contract with the National Center for Asphalt Technology, developed course curriculum information intended to introduce the Superpave mix design system as will as a basic understanding of asphalt technology to sophomore and juniors in civil engineering programs. The course materials are intended to be used as a supplement to the basic materials contained in existing asphalt undergraduate courses in materials or pavements. The materials can also be used as stand alone segments in course curriculums. The development of a senior level undergraduate curriculum has not begun at this time but may be available at a later date.
A textbook has been prepared to help those individuals teaching asphalt materials to ensure that future engineers and technicians do a better job. Students should recognize that the contents of this book cannot be their permanent technical library and to use it as they experience new challenges and face new obstacles that must be overcome in the practice of their chosen profession. That textbook is Hot Mix Asphalt Materials, Mixture Design and Construction, second edition by Freddy L. Roberts, Prithvi S. Kandhal, E. Ray Brown, Dah-Yinn Lee, and Thomas W. Kennedy. It is available from the National Asphalt Pavement Association, 5100 Forbes Blvd., Lanham, Maryland (1-888-468-6499). This textbook was used as the basis for this course and it is suggested that it be utilized for any course curricula.