In-situ lifetime extension treatment of porous asphalt: Mechanical and rheological evaluation

ABSTRACTIn this research, mechanical and rheological investigations were undertaken to assess the effect of in-situ treatment with lifetime-extension agents on porous asphalt mixtures. Field cores were extracted from five motorway sections before and after treatment with four different lifetime-extension agents, to analyze their impact on durability and ravelling resistance. Next to that, binders were extracted and recovered from the top part of the field cores to gain further understanding on the way the various lifetime-extension agents affect the field-aged binder, from a rheological point of view. The rotating surface abrasion test (RSAT) demonstrated that the treated sections exhibited 30 to 87% less aggregate loss (ravelling) compared to the untreated ones, which is attributed to the effect of the applied lifetime-extension agents. The rheological evaluation, by means of dynamic shear rheometer (DSR), revealed that most of the studied lifetime-extension agents lead to the softening and therefore the (partial) restoration of the properties of the field-aged binders, whereas one of them only aims to the sealing/strengthening of the asphaltic mortar. Irrespective of the working principle of the lifetime-extension agent, all studied agents showed a positive effect on the ravelling resistance of the porous asphalt mixtures. The results highlight that in-situ treatment with lifetime-extension agents is a promising approach for sustainable pavement maintenance. In-situ treatment is already an established pavement preservation method in the Netherlands, and its potential makes it a promising sustainable practice for broader global adoption.