Laboratory characterisation of the fatigue behaviour of a glass fibre grid-reinforced asphalt concrete using 4PB tests

This paper presents a complete experimental study of the fatigue behaviour of a glass-fibre-reinforced asphalt concrete, respecting EN 12697-24:2012, Annex D. The study is based on 38 four point bending tests, performed on 18 non-reinforced asphalt specimens and 20 geogrid-reinforced asphalt specimens. Both non-reinforced and reinforced asphalt specimens are tri-layered beams. The reinforced specimens contain two glass fibre grids, each one placed at the interface between two asphalt concrete layers. The objectives of the study were: (1) to characterise the fatigue behaviour of reinforced asphalt concrete, and to determine fatigue parameters, which can be used for pavement design, following the French pavement design method, (2) to show that glass fibre grid delays fatigue crack propagation and (3) to estimate the gain in fatigue due to the geogrid. The comparison of the fatigue curves of non-reinforced and reinforced asphalt concrete indicates that the geogrid increases fatigue life for the testing conditions, which were: fully reverse loading, displacement control, sinusoidal waveform, T = 10°C and f = 25 Hz.