Investigations into the cohesive properties and oxidation resistance of an acid cured, epoxy modified open-graded porous asphalt (OGPA) were undertaken and an associated accelerated loading test carried out at Transit New Zealand’s CAPTIF facility. Results from the Cantabro test (a test of mixture cohesion relating to the resistance of OGPA to surface abrasion losses) indicated that the early life cohesive properties of cured epoxy OGPA should be comparable to that of standard OGPA at 25°C and markedly superior at 10°C. The modulus of the cured epoxy mixture was much higher than that of the standard OGPA but this is probably of little benefit given that failure through rutting and deformation is uncommon for properly designed OGPA.
The superior oxidation resistance of the epoxy material was clearly evident in Cantabro tests conducted at both 25°C and 10°C. The CAPTIF trial demonstrated that full-scale manufacture and surfacing construction with epoxy OGPA could be easily undertaken without any significant modification to plant or the necessary operating procedures. Trafficking of the test sections resulted in early signs of surface abrasion in the control section but not in the epoxy. Early life rutting of epoxy mixtures is not likely to be greater than that of equivalent standard materials.