MEDRAD Drive and Parking Lots
MEDRAD, Inc. Headquarters along Route 910, Indiana Township, Allegheny County
Earth, Inc. performed a geotechnical investigation for the rehabilitation of the bituminous-surfaced pavement structures at MEDRAD, Inc. Headquarters along Route 910 in Indianola, Indiana Township, Allegheny County, PA. These pavements totaled 6 acres in area including MEDRAD Drive, the Blue (Parking) Lot, and the Yellow (Parking) Lot . At an average age of 15 years after their initial construction, the MEDRAD bituminous pavements were in a severely-deteriorated condition with excessive cracking and an irregular, uneven, and locally-crumpled pavement surface. Contributing to the overall poor condition of the pavements was locally-high groundwater as well as surface water infiltrating through numerous cracks in the pavements which permaturely developed as a result of their generally-ineffective subsurface drainage systems. Merely attempting to resurface these pavements would not necessarily be the best course of action for pavement rehabilitation in the long term.
The design approach for rehabilitation included controlling subsurface water beneath the pavements and restoring strength to the existing pavement structures. The re-use of existing pavement components resulted in significant cost savings when compared to totally removing such materials and hauling in new materials.
Geotechnical recommendations were developed to allow for re-establishing strength within the existing pavement structure through Full Depth (Base) Reclamation which basically involves the grinding up of the pavement structure and mixing it with a binding-type additive. This would include both the upper bituminous concrete (asphalt) and lower granular subbase portions of the pavement as well as a portion of the underlying subgrade – which would be mixed with a minimum percentage of cement additive. This stabilized material would then serve as the base course for the application of new bituminous binder and wearing courses expected to provide a useful life of at least 20 years with minimal maintenance efforts.