Influence of aromatic polyamide fibre on the early-age strength development of cold mix asphalt during curing

Cold Mix Asphalt (CMA) is widely used for pavement maintenance because of its ease of application, low energy consumption, and ability to be produced at ambient temperatures. However, its relatively slow curing process delays strength development and limits the timely reopening of repaired pavement sections to traffic. This study investigates the influence of Aromatic Polyamide Fibre (APF) on the early-age strength development of CMA during curing. Laboratory evaluations were conducted on unmodified CMA and CMA modified with 0.05% APF using workability, volumetric properties, and Marshall Stability tests after curing periods of 24, 48, 72, and 96 hours. Exploratory linear regression was performed to examine the relationship between curing duration and Marshall Stability. The results show that the APF-modified mixture had a lower measured air-void content (7.08%) than the control mixture (8.42%). The APF-modified mixture exhibited approximately 35% and 18% higher mean Marshall Stability than the control at 24 and 48 hours, respectively, while both mixtures achieved the required Marshall Stability after 72 hours. Exploratory regression indicated an overall curing-time trend but was not statistically significant and therefore interpreted descriptively rather than as a predictive model. Overall, the findings indicate that APF can improve the early-age mechanical performance of CMA, particularly within the first 48 hours of curing, highlighting its potential as a fibre reinforcement for pavement maintenance applications