Finally, the main challenges for the development of a European pavement design method are presented as well as the recent research developments that can be used for that method. To design a pavement by the AASHTO method, a number of design parameters must be determined or assumed. The asphalt mix design and modeling in Europe are presented with their inclusion in the pavement design methods. The optimum terminal serviceability index value replaces the general AASHTO design index recommendations of 2.0 and 2.5 for minor and major roads, respectively. The AASHO road test (completed in the 1950s) and subsequent AASHTO Guide for the Design of Pavement Structures (AASHTO Design Guide) provide the basis for current pavement design practices. A flexible pavement is to be designed using the AASHTO design procedure. Afterwards, French, UK and Shell methods currently in use in Europe will be presented, underlining their main components in terms of methodology, traffic, climatic conditions and subgrade. Thus, this paper firstly presents a brief historical overview of pavement design methods, highlighting early limitations of old empirical methods. 4.2.2.1 Results Figure 4-18 shows the total asphalt layer. The purpose of this section is to compare the MEPDG and AASHTO 1993 new flexible pavement designs based on the asphalt concrete layer thicknesses required to satisfy their respective design criteria. Recent researches related to the characteristics of materials and associated behavior models both for materials and pavement, made it appropriate to consider updating current pavement design methods, and especially in the USA this has already been in process while in Europe uses of the methods developed in the early 1970s. 4.2.2 Comparison of MEPDG and AASHTO 1993 New Flexible Pavement Design Thickness. The purpose of this course is to describe, in detail, each AASHTO 1993 design input parameter for both flexible (i.e. Pavement and mix design represent one of the key components within the life cycle of a road infrastructure, with links to political, economic, technical, societal and environmental issues. N 1.5 can be estimated using the AASHTO pavement design nomograph shown in Figure 2.5 (AASHTO, 1996) and using a terminal PSI of 1.5 and a reliability of 50.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |