Pavement Preservation Journal - Fall 2015 - (Page 27) LTPP Studies WMA Thin Overlays By Thomas Burchett, Tahmidur Rahman and James Sassin T he Federal Highway Administration initiated a new Specific Pavement Study (SPS) for monitoring the performance of warm mix technology under the Long Term Pavement Performance (LTPP) Program. The SPS-10 experiment, Warm Mix Asphalt Overlay of Asphalt Pavement Study, aims to compare the performance of warm mix asphalt (WMA) to that of hot mix asphalt (HMA), both in the short and long term. The study expects to reduce the current knowledge gap between the performance of WMA and HMA, which is partially attributable to the lack of documentation of long term performance. Most of the industry is adopting WMA technology, but there is no real grasp of its long-term impact. This study will aid in determining that impact and how WMA can be used to save money and improve road life and performance. Today, WMA has numerous benefits, including increased haul distances, and time to work the mix, compared to conventional HMA. WMA can also be used as a compaction aid, and in regard to emissions, is more environmentally friendly than HMA. RESEARCHING PAVEMENT PERFORMANCE The SPS-10 experiment is designed to explore how a set of primary factors affect pavement performance. These factors include: the type of WMA technology used, the climatic elements of temperature and moisture, and the traffic loading. A minimum of 16 projects will be required in the SPS-10 experiment in order to construct two projects in locations which exhibit each combination of temperature (freeze and no-freeze), moisture (wet and dry), and traffic (high and low). SPS-10 projects overlay existing asphalt pavement and consist of 500-ft. test sections with different overlay properties. Each project is required to have three core sections: HMA control, WMA produced using foaming process, and WMA created using a chemical additive. For the purpose of these studies, WMA is defined as asphalt pavement produced at 30 deg F below standard HMA production temperatures, or below 275 deg F. In addition to the core sections, the corresponding state departments of transportation (DOTs) and Canadian provinces may choose to include supplemental core sections in order to perform additional research relative to their own network. Fugro Roadware's Thomas Burchett records laydown temperatures during WMA construction Fall 2015 pavement preservation journal 27 Table of Contents for the Digital Edition of Pavement Preservation Journal - Fall 2015 President’s Message Revived Expert Task Group Will Build on Successes Next Year, Make it Nashville in October for National Conference D.C. Update: ‘DRIVE’ to Long-Term Program PPRA 2015 Fall Meeting Features International Focus NCAT: 2015 Research Cycle Under Way NCHRP: Consider Preservation in ME Pavement Design LTPP Studies WMA Thin Overlays Establish a Three-Dimensional Road Maintenance Policy MnDOT taps ‘Buried Treasure’ Beneath Busy Urban Expressway Index of Advertisers Pavement Preservation Journal - Fall 2015 http://www.nxtbook.com/naylor/FPPQ/FPPQ0118 http://www.nxtbook.com/naylor/FPPQ/FPPQ0417 http://www.nxtbook.com/naylor/FPPQ/FPPQ0317 http://www.nxtbook.com/naylor/FPPQ/FPPQ0217 http://www.nxtbook.com/naylor/FPPQ/FPPQ0117 http://www.nxtbook.com/naylor/FPPQ/FPPQ0416 http://www.nxtbook.com/naylor/FPPQ/FPPQ0316 http://www.nxtbook.com/naylor/FPPQ/FPPQ0216 http://www.nxtbook.com/naylor/FPPQ/FPPQ0116 http://www.nxtbook.com/naylor/FPPQ/FPPQ0415 http://www.nxtbook.com/naylor/FPPQ/FPPQ0315 http://www.nxtbook.com/naylor/FPPQ/FPPQ0215 http://www.nxtbook.com/naylor/FPPQ/FPPQ0115 http://www.nxtbook.com/naylor/FPPQ/FPPQ0414 http://www.nxtbook.com/naylor/FPPQ/FPPQ0314 http://www.nxtbook.com/naylor/FPPQ/FPPQ0214 http://www.nxtbook.com/naylor/FPPQ/FPPQ0114 http://www.nxtbook.com/naylor/FPPQ/FPPQ0413 http://www.nxtbook.com/naylor/FPPQ/FPPQ0313 http://www.nxtbook.com/naylor/FPPQ/FPPQ0213 http://www.nxtbook.com/naylor/FPPQ/FPPQ0113 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0412 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0312 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0212 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0112 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0411 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0311 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0211 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0111 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0410 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0310 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0210 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0110 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0409 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0309 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0209 http://www.nxtbook.com/nxtbooks/naylor/FPPQ0109 http://www.nxtbookMEDIA.com