District Department of Transportation (DDOT) retained Fort Myer Construction to replace the 27th Street, NW, Bridge over Broad Branch stream, directly adjacent to Rock Creek Park. As a result, 27th Street, NW, between Broad Branch Road and Military Road in Ward 4 was closed to vehicular, bicycle, and pedestrian traffic from late July until September 2015.
 
This project included replacement of the existing bridge with precast prestressed concrete adjacent double tee beam superstructure with an asphalt overlay, concrete sidewalk, and metal bridge railing supported by Geosynthetic Reinforced Soil-Integrated Bridge System (GRS-IBS) abutments, and stream bank stabilization. Our team also constructed and installed a vegetated geolift wall for stream bank stabilization and landscaping.

(Click to View Timelapse Video of Project from August to November 2015)

 

Project Significance

This project changed the 27th Street Bridge from a one lane bridge to a two lane bridge. Asphalt waterproofing mix (Rosphalt LT 50) was used, which is an unusual material in this area. This mix is a super concentrated thermoplastic, lower temperature, polymeric plant mix dry additive, that when combined in a Hot-Mix Asphalt (HMA) Plant with an HMA or Superpave mix design, creates a waterproofing/wearing course, which is resistant to rutting and shoving.

Benefits of Rosphalt include:

• Easy to install
• Quick return to service (as fast as 1 hour)
• Lower life cycle costs (3 ½ times longer than HMA)
• 1-step process
• Dry mix
• Proven long term durability and track record