Correction Curves to Modify Algebraically Aggregated Deductions for Jointed Concrete Pavements in Virginia

Abstract

Developing a distress-condition index representative of the roadway has always been a challenge. The development process requires in-depth understanding of the behavior of the pavement system under load and distress, thorough familiarity with the distresses, computational and analytical skill, and, above all, a very comprehensive validation process. When the Virginia Department of Transportation (VDOT) initiated its formal pavement-management operation, VDOT tried the procedure developed and outlined by the U.S. Army Corps of Engineers. Soon VDOT pavement-management personnel felt the need to have Virginiaspecific indexes and undertook an extensive effort to develop its own indexes tailored to distresses prevalent on Virginia roads and to VDOT's business objectives. The index is obtained by algebraically aggregating deductions for all the distresses in the section and subtracting that from a perfect score of 100. In 2001, VDOT completed its first-ever comprehensive condition survey on its concrete-pavement primary routes. The initial analysis revealed that the index equations were not producing representative indexes for jointed concrete pavements. Investigation revealed that the calculated condition indexes for jointed concrete were consistently lower than the expected values. It appeared that algebraically aggregated deductions need to be lowered to offset overcounting the common effects of the various distresses present. VDOT developed a relatively simple analytical approach to address this problem and came up with a technique that reduces the algebraically aggregated deductions to reasonable values. The principles and steps behind this technique are outlined and explained.