The usage of fiberglass grids in asphalt layers helps to restrain the crack propagation and thus can significantly improve pavement life time. The grids can be used in both new road constructions with decreased asphalt layer thickness and in road rehabilitations, respectively. Further, it can be used to decrease the road failure caused by settling of pavement construction in outer vehicle path of
strengthened and widened old secondary road, which is a frequent type
of pavement failure in the Czech Republic. However, the testing methods
for evaluating grid effect and its bond condition to the surrounding asphalt layers differ. This paper presents the specimen preparation, specimen quality test and results of the four-point bending creep test performed on reinforced asphalt beams. The results are then compared with specimens without a fiberglass grid. The possible modes of failure are described and discussed. The test arrangement and loading procedure was adopted from the American standard ASTM D7460, where the specimens are loaded by a constant force and mildly oscillated. However, the four-point bending test cannot properly describe the real behaviour of fiberglass grid and asphalt in real road construction. The paper therefore mentions also an alternative test arrangement for better modelling and understanding of the grid contribution to the pavement.

asphalt, bending test, glass grid, reinforcement, pavement