Longitudinal joints – bad, ugly and how to make them good

By Bob Humer, P.E.

The longitudinal joints are often the weakest link in an otherwise good performing asphalt pavement. 

Unless creating a hot-joint by paving in echelon, the typical cold joint will have less density than the center of the paving lane. This occurs for dense-graded mixes, and to a lesser extent for SMA mixes and asphalt-rubber mixes. The deterioration of the joint area is caused by it being permeable. The permeability leads to water and air intrusion, resulting in binder oxidation and a scouring of the mix matrix caused by the combination of traffic and water intrusion. This leads roads to early maintenance/repairs of the joint area, and on airports to earlier-than-anticipated overlays to avoid the risk of Foreign Object Damage (FOD) from dislodged mix. These are the costly results of failing joints and the associated reduction in service life. 

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What is jet fuel resistant asphalt?

Should you consider specifying it?

By Wayne Jones, P.E.

Before we delve into jet fuel resistant (JFR) asphalt pavements, perhaps a bit of review is in order.

According to the Asphalt Institute’s “MS-25 Asphalt Binder Testing” manual, asphalt cement “is the dark brown to black cementation material in which the predominant constituents are components that occur in nature or obtained in petroleum processing.”

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