TECHNOLOGY TRANSFER. A CHANGE FOR THE BETTER

This article reviews several FHWA demonstration projects that relate to rehabilitating Portland cement highway concrete pavements on the existing highway network. In one project involving concrete pavement restoration, various types of equipment, materials, and techniques to rehabilitate Portland cement concrete pavements are demonstrated under actual field conditions. The techniques include partial and full depth slab repairs, restoration of load transfer, resealing joints, slab subsealing, and pavement texturing. New materials include the pozzolans in subsealing operations, silicone and hot-poured elastomeric type sealants, various types of polymer concrete and other fast setting cements, and load transfer devices. Another project promotes pavement recycling. Not only is recycling cost effective, but the crushing of the aggregates into smaller sizes reduces D cracking. Another project involves using prestressing of concrete in concrete pavement overlay rehabilitation. This holds much promise for not only providing a pavement using less materials but one which approaching the concept of a maintenance-free system.