Evaluation of fatigue performance at different temperatures

• Main Author: Minhoto, Manuel
• Publication Date: 2009
• Other Authors: Pais, Jorge, Pereira, Paulo
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: http://hdl.handle.net/10198/1512
• topic: Asphalt mixtures; Fatigue resistance; Temperature; Four point bending tests; Flexible pavements

The fatigue performance of asphalt mixtures is used to predict pavement life to control the cracking in the asphalt layers. The design of an asphalt pavement is usually made for a specific temperature, what is intended to represent the pavement behaviour throughout a whole year. For damage analysis during a year, along which the pavement temperature constantly varies, it is necessary to calculate the fatigue performance of pavements at a wide range of temperatures. Thus, this paper presents the evaluation of the fatigue response of two asphalt mixtures, a conventional and an asphalt rubber mixture. Frequency sweep tests were also performed to evaluate the stiffness modulus. The fatigue test results showed that the fatigue life decreases when the test temperature decreases up to a certain value. After that value, the fatigue life increases when the test temperature decreases. To explain this phenomenon, this paper presents the preliminary tests carried out to measure the temperature inside the testing specimens to verify possible discrepancies between the climatic chamber temperature and the specimen temperature.