Project Level Pavement Evaluation Using FWD, GPR, and Video Logging and Its Application in Pavement Rehabilitation in Indiana

: Pavement rehabilitation is a major activity for all highway agencies. Accurate and efficient measurement of the rehabilitated pavement performances becomes more and more important in this procedure. In the last 10 years, significant improvements have been made in pavement nondestructive evaluation. NDT (non-destructive testing) has gained popularity because of its advantage in comparison to laboratory testing. Some of these advantages include minimal or no damage to structure, in-situ full-scale testing, relatively low operational cost, and short test duration. The INDOT (Indiana Department of Transportation) has a project level pavement evaluation program that began several years ago. This project level evaluation program employs FWD (falling weight deflectometer), GPR (ground penetration radar) and video logging. The program provides valuable information about pavement performance characteristics and offers useful tools for developing pavement rehabilitation strategies, specifically overlays and pavement underseals. On the other hand, the state of Indiana had rehabilitated its flexible, rigid or composite pavement almost exclusively with asphalt. This AC (asphalt concrete) overlay can improve the condition of existing pavement and extend the service life of the existing pavement structure. This paper thus describes the experiences of pavement overlay with AC thickness design for the INDOT (Indiana State Department of Transportation) using the AASHTO (American Association of State Highway and Transportation Officials) 1993 Guide, the MEPDG (Mechanistic-Empirical Pavement Design Guide). In order to do that, backcalculation program was compared and evaluated to obtain subgrade resilient modulus and k value for pavement rehabilitation using FWD data. Video logging provides IRI (international roughness index) and rut depth for existing pavement condition and GPR provides thickness or pavement bonding conditions in pavement. Emphasis is placed on observations and issues encountered using the current AASHTO 1993 Guide and the MEPDG.