Study on Low-Temperature Cracking Resistance of Carbon Fibre Geogrid Reinforced Asphalt Mixtures Based on Statistical Methods

In order to investigate the effects of surface combined body (SCB) type and geosynthetic type on the low-temperature cracking resistance of reinforced asphalt mixtures, low-temperature bending damage tests were conducted on both unreinforced and reinforced double-layer beam specimens, respectively. At the same time, the load-deflection curve during loading was corrected using the linear fitting difference method to determine the mid-span deflection. Then, the low-temperature cracking resistance of the reinforced asphalt mixtures was comparatively analyzed by calculating the maximum flexural tensile strain (<i>ɛ</i>_B). Finally, the extent to which the geosynthetic type and the SCB type affect the low-temperature cracking resistance of the reinforced asphalt mixtures was investigated by means of a two-way analysis of variance (ANOVA). The results showed that the greater the tensile strength of the geosynthetics, the greater the mid-span deflection and <i>ɛ</i>_B of the reinforced double-layer beam specimens. The order is carbon fibre geogrid (CCF) > glass/carbon fibre composite qualified geogrid (GCF) > fibreglass-polyester paving mat (FPM) > unreinforced (UN). In the case of reinforcement, the <i>ɛ</i>_B of the AC-13/AC-20 combination is lower than that of the AC-20/AC-25 combination, with a significant difference, especially in the case of geogrid reinforcement. Analysis by a two-way ANOVA shows that the order of influence on <i>ɛ</i>_B ranks as geosynthetic type > SCB type. This study provides a scientific basis for the rational selection of carbon fibre geogrid-reinforced asphalt pavement structures.