Influence of ageing and moisture conditions on the ravelling resistance of the micro-surfacing mix

In this study, the durability of the micro-surfacing mix was assessed by investigating the synergistic effect of ageing and moisture conditioning on ravelling. A total of 30 combinations of conditioning protocols were considered. Ageing time and temperature were varied between 85- 105 degrees C and 24- 120 h, whereas moisture conditioning time and temperature were varied between 25-60 degrees C and 24-192 h. The results showed that after the mix was fully cured, increased stiffness led to a substantial decrease in ravelling. Synergistic assessment of ageing and moisture showed that ageing temperature had the highest, whereas moisture conditioning time had the least influence on ravelling. It was noticed that once the specimens were fully cured and subjected to further ageing, the effect of moisture conditioning temperature on ravelling became minimal. Overall, laboratory investigations pointed out that micro-surfacing should be applied during favourable environmental conditions, facilitating faster moisture loss and strength gain to improve durability.