Precast Concrete Pavement on I-66 In Virginia

Highway agencies are continuously striving to build or repair in an accelerated manner and are evaluating materials and methods to provide long lasting pavements. To expedite construction and reduce the associated traffic delay and provide longevity, precast concrete slabs have been used for more than 10 years with successive improvements in processes and systems. The Virginia Department of Transportation (VDOT) has recently tried two precast systems along with conventional cast-in-place repairs on I-66 near Washington, D.C. The existing pavement was jointed reinforced concrete pavement. One precast system used reinforced slabs with doweled joints and was called Precast Concrete Pavement (PCP). The other system used transversely prestressed slabs, post-tensioned in the longitudinal direction, and was called Prestressed Precast Concrete Pavement (PPCP). Both the PCP and PPCP systems are performing satisfactorily after one year of traffic and the contractor was also satisfied with the constructability. One of the major concerns is the potential for wide expansion joints in the PPCP and eventual loss of support there. There were very few cracks in the PPCP section, mainly originating from grouting holes, cracks in the block- out patches, cracks and loss of epoxy at lifting hook holes, and corner breaks. PCP slabs showed some mid-slab cracks immediately after opening to traffic but they are still tight and stable after 1.5 years of traffic.