Aggregate and disaggregate statistical evaluation of the performance-based effectiveness of long-term pavement performance specific pavement study-5 (LTPP SPS-5) flexible pavement rehabilitation treatments

Engineers continually seek effective techniques for preserving highway infrastructure. Using data from the specific pavement study#5 of the long-term pavement performance (LTPP) programme's western region, this article evaluated the performance of eight flexible pavement rehabilitation treatments. Aggregate and disaggregate post-treatment performance models were developed for each treatment. Effectiveness was measured in the short term (roughness reduction) and long term (estimated treatment service life and area bounded by the performance curve (ABP)). The results showed that compared to 2-inch treatments, 5-inch treatments were on average more effective in terms of the following measures: 47% (estimated service life) and 35% (ABP) depending on the level of surface preparation, mix type and initial pavement condition. Also, relative to minimal surface preparation, intensive surface preparation generally yielded greater effectiveness: 25% (estimated service life) and 49% (ABP) depending on added thickness, mix type and initial pavement condition. Compared to recycled mix treatments, virgin mix was marginally more effective. Finally, compared to pavements treated in poor condition, those treated in good condition were significantly more effective. Treatment effectiveness models were developed for predicting the expected effectiveness of future treatments on the basis of attributes such as treatment type, added layer thickness, level of surface preparation and mix type.