United States Department of Transportation
[PDF-1.26 MB]
Details:
-
Creators:
-
Corporate Creators:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Corporate Publisher:
-
Abstract:Forty or more years ago hundreds of miles of Maine highways were constructed of Portland Cement
Concrete (PCC) to a width of 5.5 to 6.0 m (18 to 20 ft). Since that time these same highways have been
paved and widened to 6.7 or 7.3 m (22 or 24 ft) with hot bituminous pavements to accommodate
increased traffic volumes and enhance roadway safety. Bituminous materials were used in place of
concrete due to the ease of placement and price of material.
PCC is a rigid pavement capable of supporting weight with little deflection. In contrast, hot bituminous
pavement is flexible and will flex to distribute weight across the roadway. When the highway is expanded
beyond the concrete slab, there is a sharp decrease of support for the bituminous pavement resulting in
settlement over prolonged use. This settlement may also be compounded by poor drainage capabilities of
the underlying soils causing the unsupported pavement to drop lower than the existing height of the
concrete supported pavement. This creates a longitudinal crack aligning with the concrete slab edge
roughly 0.3 to 1 m (1 to 3 ft) from the right edge of pavement. Pavement to the right of this crack
deteriorates to the point where maintenance crews attempt to smooth it out with cold patch year after year.
Paving over the entire roadway is an option but, due to reflective cracking, the edge of pavement begins to
deteriorate within 2 or 3 years.
It is the intent of this experimental project to explore various shoulder treatments to increase support of
the extended roadway and hopefully decrease or eliminate deterioration of the shoulder pavement.
-
Format:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
