Construction

Before a pavement is placed the surface to be paved must be prepared. Pavements constructed without adequate surface preparation may not meet smoothness specifications, may not bond to the existing pavement (in the case of overlays) or may fail because of inadequate...

HMA is produced in a plant that proportions, blends, and heats aggregate and asphalt to produce an HMA that conforming to JMF  requirements.  There are two basic types of HMA plants commonly in use today: the batch plant, and the drum mix plant.  Batch plants produce...

Mix transport involves everything required to convey HMA from a production facility to a paving site including truck loading, weighing and ticketing, hauling to the paving site, dumping of the mix into the paver or material transfer vehicle hopper, and truck return to...

Mix laydown involves everything used to place the delivered HMA on the desired surface at the desired thickness.  The asphalt paver is the principal machine involved in mix laydown and is assisted by the material transfer vehicle (MTV) or material transfer device...

Quality has become one of the most important consumer decision factors in the selection among competing products and services.  This is true not only for individual consumers but also for large corporations, government organizations and the taxpaying public as a...

Specifications are used (1) to convey information concerning desired products from a buyer to a seller or potential seller, (2) as a basis for competitive bidding for the delivery of products, and (3) to measure compliance to contracts.  Typically, four types of...

Segregation and temperature differentials are construction-related HMA pavement problems that can lead to early pavement failure.  Washington State has been a leader in researching, identifying and combating these problems. Aggregate Segregation Aggregate segregation...

Compaction is the process by which the volume of air in an HMA mixture is reduced by using external forces to reorient the constituent aggregate particles into a more closely spaced arrangement.  This reduction of air volume in a mixture produces a corresponding...