A study was conducted on the survival of asphalt concrete (ac) overlays on the illinois interstate highway system. Data were obtained from the illinois pavement feedback system (ipfs) data base for 410 ac overlay construction sections placed on jointed reinforced and continuously reinforced concrete pavement (jrcp and crcp) between 1964 and 1989. The overlays ranged in thickness from 1.5 To 6.0 In. Both in-service life and 18-kip equivalent single-axle loads (esals) carried to rehabilitation of the overlay were analyzed through the use of survival curves. The survival of the 213 ac overlays of jrcp sections is reported. The mean age and accumulated esals at the time of overlay rehabilitation were estimated for categories of overlay thickness (thin and thick) and portland cement concrete durability (with and without d cracking). The analysis indicated that each of the factors considered, along with traffic level, had a significant effect on the life of the overlays. Thick overlays lasted substantially longer and carried substantially more traffic than thin overlays on both d-cracked and non-d-cracked pavement. Both thin and thick overlays performed much better on pavements without d cracking than on pavements with d cracking. This paper appears in transportation research record no. 1307, Pavement analysis, design, rehabilitation, and environmental factors 1991.
Abstract