Staged Survival Models for Predicting Duration of Asphalt Concrete Overlays (05-1169)
Yuhong Wang, University of Kentucky

A large portion of expenditures on pavements is spent on preventative and rehabilitative maintenance programs instead of new construction. In Kentucky, the primary maintenance program on the Interstates and Parkways includes asphalt concrete (AC) overlays over AC pavements and AC overlays over fractured Portland cement concrete (PCC) pavements. Prediction models are required to estimate the performance of the two types of overlays for Kentucky’s pavement management system (PMS). The distress development patterns of the two types of overlays were analyzed based on all the historical data in Kentucky’s PMS. The patterns show that in general the distress developments can be divided into three stages: slow increase, moderate increase, and rapid increase. Based on the distress development patterns, two stage survival models were proposed to predict the resurfacing cycles. The first stage of the survival model can be used to predict the duration of an overlay before a new resurfacing is required, while the second stage of the survival model can be used to predict the time window during which another overlay must be applied to avoid the condition deteriorating to the third stage.