Ultrathin Whitetopping in California and Nevada: A 13-Year Performance Perspective of Performance Based on Joint Spacing, Thickness, and Traffic Loading

Since the first California ultrathin whitetopping (UTW) was constructed at a mortuary, UTW has proven not to be a dead concept but a steadily growing process providing low-maintenance pavements for streets, bus pads, intersections, and parking lots. A Pavement Condition Index (PCI) survey of 18 projects using the Micropaver protocol yielded ratings of excellent to very good for 2- to 13-year old pavements located from coastal southern California to Reno, Nevada. A constant in considering UTW for pavement rehabilitation has been the cost of saw-cutting joints at the close spacings recommended by the American Concrete Pavement Association (ACPA). Based on the finding that 90% of projects constructed with joint spacings larger than those recommended by ACPA have PCIs > 85 (excellent), UTW subjected to car-only traffic can have larger spacings.