THICKNESS DESIGN OF CONCRETE RESURFACING

Abstract

Many miles of the nation's highway system have reached or exceeded their design lives in terms of traffic loading. A large portion of the highway system is being revitalized as part of the federal government's 4R program. The 4R program consists of rehabilitation, restoration, resurfacing, and reconstruction. Because of its cost-effectiveness and functional benefits, resurfacing is and will continue to be an important part of the 4R program. Portland cement concrete has been used to resurface pavements for over fifty years. Concrete resurfacing provides a relatively low maintenance service life. There are basically four types of concrete resurfacing. These are bonded, directly placed, unbonded, and concrete resurfacing over an existing asphalt pavement. concrete resurfacings have been designed in the past by experience or engineering judgment. Recognizing the inherent weaknesses in the existing design procedures, an investigation was sponsored by the Portland cement Association to develop more rational concrete resurfacing design procedures. This paper presents new thickness design procedures for unbonded and bonded resurfacings. The procedures involve a pavement condition survey, non­ destructive load testing at the pavement surface, evaluation of in-situ material properties of the existing pavement, and use of design charts to compute required resurfacing thickness. The unbonded and bonded concrete resurfacing procedures are based on providing a resurfaced pavement that is structurally equivalent to a full depth concrete pavement designed for anticipated future traffic.