(July 17, 2015) – The new travel lane on US 29 in Columbia will have “green” asphalt pavement but drivers will not be able to see a difference.  The Maryland Department of Transportation’s State Highway Administration (SHA) is using 2,600 tons (5.2 million pounds) of recycled material on its $32.7 million widening project on northbound US 29 between Seneca Drive and MD 175 in Columbia, Howard County.

The recycled material is called Foamed Asphalt, which is comprised of reclaimed asphalt pavement and cement. In general, foamed asphalt production involves injecting water and into a special chamber that contains millings from other resurfacing projects which causes the asphalt to foam and bind together. This produces a useable material that is 10 to 15 times the original volume of the millings. Crews then mix the material with Portland cement to create foamed asphalt.  The recycled material will be used as a base course and will be the proper load-bearing strength after compaction.

“Using recycled materials in road building and maintenance supports practical design principles,” said SHA Acting Administrator Douglas Simmons.  “The amount of material in this case is about half the volume of water in an Olympic-sized swimming pool.  Using less new asphalt and wasting less from other projects is an environmental benefit.”

 

 

 

This weekend, crews will apply the foamed asphalt base on northbound US 29. Single lane closures are likely Friday and Saturday between 8 p.m. until 5 a.m. each subsequent morning, weather permitting.

The widening of northbound US 29 between Seneca Drive and MD 175 is nearly 40 percent complete. SHA’s contractor is Allen Myers of Fallston. Click here for more information about the US 29 project.