الملخص الإنجليزي
Pavement temperature is an important input for proper selection and testing of the pavement materials, as well as the evaluation and monitoring of pavement performance. The Strategic Highway Research Program (SHRP) introduced a new specification by which asphalt binders are selected; namely the Superpave binder specification. This is a performance-based specification that links the performance of an asphalt binder to the environment in which it is expected to serve as well as vehicular loading. Superpave binders are selected based primarily on the lowest and highest pavement temperatures expected at a project. These are derived from an extensive database of climatic data from about 7500 sites in the US and Canada.
Most of the developed models, testing and performance criteria for asphalt pavements were developed in the US and adopted in many countries. These criteria are not necessarily valid for all countries, taking into consideration the difference in climatic conditions. Therefore, there is a need to investigate pavement temperature conditions as well as to establish a reliable database for the pavement temperatures in various regions of Oman. This database will be the major source of information for verifying the material selection and testing parameters. Moreover, it will be a major input for investigations of pavement performance due to traffic loading and/or environmental effects.
The objective of this study is to investigate the relation between air and pavement temperatures in Oman through the set-up of a pavement temperature monitoring station. The monitoring station will collect air and pavement temperature at various depths as well as solar radiation. The study further entails the collection and statistical analysis of climatic data from weather stations around Oman to develop a comprehensive climatic database. This database may, subsequently, be used to provide the necessary information that will enable the selection of appropriate Performance Grades (PG) for various Regions in the country.
High and low pavement temperature prediction models for Oman were developed, using regression analysis, based on collected field data of air and pavement temperatures at various depths and solar radiation. These models achieved a high goodness-of-fit and were found to be a better representation of collected field data in Oman than the Strategic Highway Research Program (SHRP) and Long Term Pavement Performance Program (LTPP) models. Furthermore, a historical climatic database was developed for ten locations around Oman. This data was used to identify highest and lowest air temperatures with various reliability levels. Corresponding highest and lowest pavement design temperatures were obtained using SHRP, LTPP and the developed SQU models. This information was used to establish appropriate PG for each location using each set of models. The SQU models are continuously being refined as more data becomes available.
