This paper was presented at the session titled `Innovative pavement design and evaluation techniques'. Since 1989, Alberta Infrastructure has used Hot In-Place Recycling (HIR) technology for the rehabilitation of several Primary Highways. The initial projects used method type specifications and were consisted to be trial projects or investigative in nature. The Department has since developed HIR End Product Specifications (EPS) and has included HIR technology as a rehabilitation option within its Pavement Design Manual. In 1998, the Department undertook a study to review the performance of selected HIR projects constructed to-date. The objective was to determine appropriate service life estimates to be used within Life Cycle Cost (LCC) analysis when comparing various rehabilitation alternatives. A further objective was to identify additional applications where HIR technology could be used. For this study, four projects were selected that were rehabilitated using HIR but were not subsequently overlaid or chip seal coated. Based upon the performance assessment of these pavements, average HIR service life estimates were determined. The performance assessment and resulting service life estimates are summarised in this paper. Also described in this paper are other potential rehabilitation applications using HIR technology including a "decision tree" Project Selection Chart that was developed to assist pavement designers in the selection of appropriate rehabilitation strategies. Several scenarios using LCC analysis to compare various rehabilitation alternatives are presented using the newly determined HIR service life estimates and Project Selection Chart. Included in the LCC analysis is an equity resource conversation fee that was assigned to all alternatives using virgin aggregates and asphalt binder. The inclusion of this fee is meant to recognise the inherent advantage that HIR technology possesses in conserving non-renewable resources. (A)
Abstract