2008 Survey of European Composite Pavements (2010)

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4 C H A P T E R 1 IntroductionCongress created the second Strategic Highway Research Pro- gram (SHRP 2) to address the challenges of moving people and goods efficiently and safely on the nation’s highways. One focus of SHRP 2 is the rapid renewal of highways, which led to the development of SHRP 2 Renewal Project R21: Compos- ite Pavement Systems. The project objectives include develop- ing construction specifications, guidelines, and procedures; design guidelines; and training materials for composite pave- ment systems. One early task in the research is to develop a database of full-scale applications of composite pavement systems, including data on performance to date, material properties, construction details, and design considerations. In later project phases, test sections may be constructed for validation purposes. Two strategies that show great promise for providing strong, durable, safe, smooth, and quiet pavements needing minimal maintenance are 1. Surfacing of new portland cement concrete (PCC) layers with high-quality asphalt concrete (AC) layers; and 2. Placement of a two-layer wet-on-wet PCC pavement with a relatively thin, high-quality PCC surface atop a thicker, less expensive PCC layer. However, neither the structural performance nor the func- tional performance of these two types of composite pavements is well understood or documented. In addition, specifications and construction techniques for these composite pavements, especially PCC-over-PCC, have not been studied closely in the United States, thus hindering their adoption. Members of the R21 research team previously had observed both of these composite pavement systems and had discussed them with engineers in several countries, because these pave- ments have been constructed successfully in Europe for many years. On the basis of this knowledge, the research team pro- posed a brief survey of these two composite pavements inthree European countries; this was accomplished in May 2008. The performance and construction techniques were assessed, and several sections were surveyed to include in the R21 data- base. The delegation consisted of R21 project investigator Dr. Michael I. Darter of Applied Research Associates, Inc. (ARA); project co-investigator Prof. Lev Khazanovich of the University of Minnesota; and Mr. Derek Tompkins, graduate student at the University of Minnesota. The R21 delegation was hosted in the Netherlands, Germany, and Austria by colleagues from the international pavement research community: • Mr. Adrian van Leest of CROW Technology Platform in Ede, Netherlands, first hosted the R21 delegation on May 6–10, 2008, to review several sections of PCC/PCC and, along with Mr. George Jurriaans of ECCRA, a large AC/continuously reinforced concrete pavement (CRCP) construction project on the A73 motorway. • R21 project consultant Dr. Walter Fleischer of Heilit+ Woerner GmbH in Munich, Germany, hosted the delegation on May 11–14, 2008, to review German research, German specifications, in-field PCC/PCC sections along the A93 motorway, and construction techniques for PCC/PCC pave- ments on 21 km of the A6 motorway. • Dr. Hermann Sommer, formerly of VOZfi (Association of the Austrian Cement Industry Research Institute) in Vienna, Austria, and Stefan Krispel of VOZfi hosted the R21 dele- gates on May 15–16, 2008, to review PCC/PCC research and techniques and to visit PCC/PCC pavement sections along more than 100 km of the A1 motorway. Great appreciation is expressed to all of these individuals for hosting the R21 team in their countries. It required signif- icant time and resources to plan and accompany the team, as well as to assist with the collection of data for the projects included in the R21 database. Without their assistance, this

5 trip and the valuable information gained from it would not have been possible. This report documents information gained from a brief survey of composite pavement systems in three European countries. Chapter 2 describes each of the projects examined during the field survey. Chapter 3 documents the two-layerexposed aggregate concrete (EAC) composite pavements, and Chapter 4 documents the two-layer thin asphalt surfacing over concrete composite pavements. Chapter 5 sets out criti- cal observations drawn from the survey on both types of pavements for construction of test sections under SHRP 2 Renewal Project R21.