Impact of Joint Spacing on Bonded Concrete Overlay of Existing Asphalt Pavement in the AASHTOWare Pavement ME Design Software

Abstract

This paper describes the impact of joint spacing or panel size on the performance and relative cost of short jointed bonded concrete overlay of asphalt (SJPCP) pavement using the AASHTO Pavement ME Design procedure. Joint spacing, or panel dimension, is a critical design issue that greatly affects both performance and cost of the SJPCP as well as conventional jointed plain concrete pavement (JPCP) overlays. In fact, pavement performance is more dictated by the panel size than thickness. Three factors that greatly affect the performance of SJPCP include (1) traffic (truck) volume, (2) wheel load placement and panel size, and (3) layer bonding of portland cement concrete (PCC) to asphalt concrete (AC). This paper focuses on the second point, wheel placement or panel size, which defines the location of critical stresses, location of fatigue damage along the transverse joint, and initiation of corner, longitudinal, and transverse fatigue cracking. Portions of the bonded concrete overlay of asphalt-mechanistic empirical (BCOA-ME) procedure developed by the University of Pittsburgh were implemented into the AASHTOWare Pavement ME Design (Pavement ME) software (version 2.3, July 2016) for joint spacing ranging from 1.5 to 2.4 m (5 to 8 ft) and appropriate thicknesses. This range of joint spacing was implemented based on the impact of joint spacing on BCOA fatigue cracking as described in this paper.