A study of the fatigue properties of grouted macadams

Abstract

Grouted macadams can be seen as semi-flexible materials. Their behavior is still not well understood. This paper presents a series of laboratory tests, carried out at the University of Nottingham, with the goal of contributing to a better understanding of the fatigue performance of such materials. Two types of fatigue tests were used in this investigation (2- and 4-point bending tests), and the results obtained for the grouted macadam mixture are compared with those obtained for a conventional asphalt mixture in the United Kingdom. Rest periods between load applications were varied in another series of 4-point bending fatigue tests, with the aim of determining a shift factor for grouted macadam fatigue characteristics, in order to use the laboratory determined results in the design of pavements incorporating grouted macadam mixtures. The analysis of the results obtained during this investigation has shown that the traditional failure criterion used in fatigue tests may not properly represent the fatigue life of grouted macadams.