Search Results (2)

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 (ɛ_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 ɛ_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 ɛ_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 ɛ_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. Full article

Geosynthetic materials (i.e., geogrids, geotextiles and other geocomposites) act as an interlayer system and are widely used in construction applications. In pavement structures, geosynthetic layers provide potential benefits such as reinforcement, reflective cracking mitigation, increased fatigue life, and improved drainage and filtering. However, few studies have addressed the installation and construction practices of geosynthetics in pavements. Furthermore, the study of geosynthetics and their contribution during construction are limited. In this paper, a full-scale field study was conducted and three trial sections were constructed; two types of geosynthetics, a fibreglass geogrid and a geogrid composite, were installed in the asphalt binder course and at the interface between the subgrade and base layer, respectively, to be compared with a control section without geosynthetic reinforcement. Trial sections were instrumented to monitor the pressure applied on the subgrade, the strain in the base lift of the asphalt binder course, the temperature, and the moisture within the pavement structure during construction. In addition, post-construction field testing was performed to measure the stiffness of the pavements after construction. The results indicated that geosynthetic-reinforced pavements can maintain pavement resilience during construction and significantly mitigate the disturbances caused by construction activities. The geogrid embedded in the asphalt layer was demonstrated to reduce the pressure at the subgrade caused by paving equipment by 70% compared with the control section, while simultaneously reducing the longitudinal and transverse strain at the bottom of the asphalt layer by 54% and 99%. Observations from the geogrid composite test section also demonstrate the potential to minimize the impacts of future freeze–thaw at the subgrade due to the improved drainage and indirect insulation effect. Full article