This synthesis is concerned with the resurfacing of existing portland cement concrete (rigid) and bituminous cement concrete (flexible) pavements with portland cement concrete (hereinafter referred to as "" concrete""). Concrete resurfacings have been used for one or more of the following purposes: (a) to restore the rideability of the existing pavement, (b) to provide an appropriate surface texture to the existing pavement, or (c) to restore or increase the load-carrying capacity of life or both of the existing pavement. The term ""resurfacing"" is considered inclusive of all these purposes and is used throughout this synthesis instead of the frequently used term ""overlay."" This report deals primarily with highway experience, but city street, county road, and airfield experience have been included where it has been considered to be appropriate.   The report for this topic can be purchased at https://www.trb.org/news/blurb_detail.asp?id=3458