A construction specification is just like a recipe: It spells out the types and quantities of ingredients and the steps that should be followed to make a great product every time.
Asphalt pavements are made by measuring and combining a precise formulation of aggregates, binder, and additives to suit the road’s anticipated traffic volume and other considerations. This mixture is then placed on the roadway and methodically compacted with heavy equipment to smooth the surface and squeeze out the right amount of air.
In 2016, an Iowa DOT research project investigating the necessary amount of compaction led to several changes to Iowa’s asphalt pavement specifications. The next phase of that project, which concluded in 2021, sought to verify that the updated specifications do indeed result in better-performing pavements. Evaluating three types of asphalt specimens that were made using the old specifications and comparing them with samples made with the new specifications, researchers found that the new specimens were more resistant to rutting, fatigue cracking, and low-temperature cracking.
When built with the new specifications, Iowa’s roads will likely need less maintenance and repair – a win for taxpayers and all road users alike.
Learn more about the project in Iowa DOT’s new research brief.
Delivering targeted solutions for Iowa's transportation future.
Powered by Qmarkets
Supported browsers are Google Chrome, Mozilla Firefox, Microsoft Edge, IE 11+, Opera, and Safari.