Correlation between monotonic and repetitive test results in bituminous mixtures

Abstract

The pavement response to traffic repetitive loading is represented and evaluated more accurately in laboratory by using repetitive testing. However, the use of monotonic testing is very common to evaluate the behavior of bituminous mixtures and to control their quality when applied in pavements. Thus, the relationship between the results of monotonic and repetitive tests performed in this work is the main base of analysis of the accuracy of monotonic tests to assess the performance of bituminous mixtures in situ. Fatigue cracking and rutting are the main types of distress in flexible pavements in countries with warm temperatures. Initially, the behavior of several dense mixtures is determined by using normalized repetitive testing, namely bending beam tests in four points (fatigue) and repetitive simple shear tests at constant height (rutting). Then, similar mixtures are tested in a monotonic manner by using compression, tensile and shear testing. The monotonic tests are performed at different temperatures and strain rates, so as to reproduce a wide range of in situ conditions. The main conclusions result from the statistical comparison between the repetitive and the monotonic tests. Essentially, this work intends to evaluate the possibility of characterizing the performance of bituminous mixtures in situ by using the specific monotonic tests herein developed.