Innovative solutions to buried Portland concrete cement roadways : construction report.

PDFTech Report99-11Portland cement concreteBituminous pavementsConcrete pavementsRigid pavementsSettlement (Structures)Longitudinal crackingHot mix paving mixturesInnovationConstructionMaineMaine. Dept. of TransportationMarquis, BrianMaine. Dept. of Transportation. Transportation Research DivisionUS Transportation CollectionMaine has hundreds of miles of highway that were constructed of Portland Concrete Cement(PCC) roughly 6 to 6.1 meters (18 to 20 feet) wide forty or more years ago. Since that time thesesame highways have been paved and widened to 6.7 or 7 meters (22 or 24 feet) with hotbituminous pavements to accommodate increased traffic volumes. Bituminous materials wereused instead of concrete due to the ease of placement and price of material.Concrete is a rigid pavement capable of supporting weight with little deflection. Bituminous is aflexible pavement that will bend to distribute weight across the roadway. When the highway isexpanded beyond the concrete slab there is a sharp decrease of support for this bituminouspavement resulting in settlement over prolonged use. This settlement may also be compoundedby poor drainage capabilities of the underlying soils causing the unsupported pavement to droplower than the existing height of the concrete supported pavement. This creates a longitudinalcrack aligning with the concrete slab edge about 0.3 to 1 meter (1 to 3 feet) from the right edgeof pavement. Pavement to the right of this crack deteriorates to the point where maintenancecrews attempt to smooth it out with cold patch year after year. Paving over the entire roadway isan option but, due to reflective cracking, the edge of pavement begins to deteriorate within 2 or 3years