Cost-Effectiveness and Performance of Overlay Systems in Illinois Volume 2: Guidelines for Interlayer System Selection Decision When Used in HMA Overlays

摘要

In an effort to control reflective cracking in hot-mix asphalt (HMA) overlays placed over Portland CementConcrete (PCC) pavements, several reflective crack control (RCC) systems, including interlayer systems,have been used. However, the cost-effectiveness of interlayer systems is still in doubt due their performanceand additional costs. In this project, a decision making procedure to aid in the selection of cost-effectiveinterlayer systems was developed. As a core step in evaluating the benefit-cost ratio (B/C) of interlayersystems, a user-friendly life-cycle cost analysis (LCCA) program, CIND (Cost-effective INterlayer systemDecision program) was developed. Based on sensitivity analysis, a B/C prediction model was proposed, whichtakes into account a performance benefit ratio (PBR) parameter, a material cost ratio (MCR), and aconstruction time ratio (CTR). Using the B/C model, a table was developed which allows the user todetermine the most cost-effective interlayer system in a rehabilitation project for a given equivalent single-axleload (ESAL) level, representative low temperature (TL), and existing concrete pavement joint spacing (JS).Finally, a decision making tree was constructed to simplify the process of determining the most cost-effectiveand compatible interlayer system for a given project. Depending on project significance and/or informationavailability, pavement engineers can select from one of three newly developed B/C evaluation tools (in orderof sophistication): application tables, B/C prediction model, and the CIND computer program. Using thesetools, it was found that B/C increases as PBR increases or MCR and CTR decrease. In general, System D iscost-effective in a wide range of ESALs and TL values; especially in a cold region with lower traffic volume.The application range is reduced with the increase of JS, however. System E is relatively cost-effective only inwarm regions having higher traffic volume.