Progress Of Superpave Superior Performing Asphalt Pavement

A major result of the research conducted under the Strategic Highway Research Program from 1987 to 1993 was the development of the Superpave (Superior Performing Asphalt Pavement) system for the comprehensive design of asphalt pavements. These 14 contributions describe the experience to date in the

The Strategic Highway Research Program (SHRP) was a highly focused, ambitious research effort that targeted four specific areas for intense study over the time frame from 1987 to 1993. Asphalt was one of the four study areas. This report describes the Superpave system, the final product of the asphalt research program; and the various parts that comprise its operational characteristics. In all, the final report of the SHRP Asphalt Research Program consists of five parts, the contents of which are briefly described in this report. Reference is made within this report to specific details within the other four parts for readers who want a more detailed description of the methodology, test methods, and theory behind Superpave.

The primary objective of this full-scale accelerated pavement testing was to evaluate the performance of unmodified and polymer modified asphalt binders and to recommend improved specification tests over existing SUperior PERforming Asphalt PAVEment (Superpave) binder performance grading methodologies. Candidate replacement tests were evaluated via their ability to discern fatigue cracking resistance and rutting. Two fatigue cracking specification tests were identified as more capable in capturing performance than others: binder yield energy and critical tip opening displacement. Two rutting specification tests that quantify irrecoverable deformations exhibited the best strength to capture rutting: multiple stress creep and recovery and oscillatory-based nonrecoverable stiffness. Based on the full-scale performance and laboratory tests, crumb rubber (recycled tires) modified asphalt (Arizona wet process) was shown to significantly slow or stop the growth of fatigue cracks in a composite asphalt pavement structure. A hybrid technique to modify asphalt with a combination of crumb rubber and conventional polymers (terminally blended) exhibited good fatigue cracking resistance relative to the control binder. Also, a simple addition of polyester fibers to asphalt mix was shown to have high resistance to fatigue cracking without the use of polymer modification. The research study also quantified the capabilities of the National Cooperative Highway Research Program's mechanistic-empirical pavement design and analysis methodologies to predict rutting and fatigue cracking of modified asphalts that were not captured in the calibration data from the Long-Term Pavement Performance program. Falling weight deflectometer, multidepth deflectometer, and strain gauge instrumentation were used to measure pavement response. The results illustrated that the nationally calibrated mechanistic-empirical performance models could differentiate between structural asphalt thickness but had difficulty differentiating modified from unmodified asphalt binder performance. Nonetheless, the mechanistic-empirical performance ranking and predictions were enhanced and improved using mixture-specific performance tests currently being implemented using the asphalt mixture performance tester.

Highway engineers are facing the challenge not only to design and construct sustainable and safe pavements properly and economically. This implies a thorough understanding of materials behaviour, their appropriate use in the continuously changing environment, and implementation of constantly improved technologies and methodologies. Bituminous Mixtures and Pavements VII contains more than 100 contributions that were presented at the 7th International Conference ‘Bituminous Mixtures and Pavements’ (7ICONFBMP, Thessaloniki, Greece 12-14 June 2019). The papers cover a wide range of topics: - Bituminous binders - Aggregates, unbound layers and subgrade - Bituminous mixtures (Hot, Warm and Cold) - Pavements (Design, Construction, Maintenance, Sustainability, Energy and environment consideration) - Pavement management - Pavement recycling - Geosynthetics - Pavement assessment, surface characteristics and safety - Posters Bituminous Mixtures and Pavements VII reflects recent advances in highway materials technology and pavement engineering, and will be of interest to academics and professionals interested or involved in these areas.

This book presents selected articles from the 5th International Conference on Geotechnics, Civil Engineering Works and Structures, held in Ha Noi, focusing on the theme “Innovation for Sustainable Infrastructure”, aiming to not only raise awareness of the vital importance of sustainability in infrastructure development but to also highlight the essential roles of innovation and technology in planning and building sustainable infrastructure. It provides an international platform for researchers, practitioners, policymakers and entrepreneurs to present their recent advances and to exchange knowledge and experience on various topics related to the theme of “Innovation for Sustainable Infrastructure”.