Comparison of the effect of accelerated curing with post-construction induction heating and natural curing on the self-healing index of cold asphalt mixture

Document Type : Research Paper

Authors

1 semnan university

2 Assistant Professor, Civil Engineering Department. Faculty of Engineering, University of Guilan, Rasht, Iran

Abstract

Cold asphalt has drawbacks such as lower shear strength due to poor adhesion between bitumen and aggregate (caused by insufficient heating during production), limiting its use on high-traffic roads. Additionally, the weak bond between bitumen and aggregate leads to faster crack initiation and propagation in these pavements. The primary objective of this research is to compare the self-healing capacity of cold asphalt cured with post-construction electromagnetic induction heating and cold asphalt cured using the conventional method. For the laboratory specimens, siliceous aggregates, 63-micron iron powder (as an induction agent), cationic emulsion bitumen, and rock powder were used. Specimens were prepared using the Marshall method at two curing ages of 7 and 21 days, and by two methods: accelerated curing (with initial induction heating for 240 seconds) and natural curing (without initial induction heating). Subsequently, the specimens were subjected to Indirect Tensile Strength (ITS) tests at temperatures of 0, 15, and 40 degrees Celsius. After failure, both sets of specimens were subjected to restorative induction heating to evaluate their self-healing capacity. The specimens were then retested using the Indirect Tensile Strength (ITS) test at the same temperatures to calculate the self-healing index by comparing the strength of the specimens before and after failure and induction heating. The results show that with increasing age, the self-healing index rate of cold asphalt samples with induction heating during curing decreases. This becomes more pronounced with increasing test temperature. This trend indicates a significant effect of heating during curing and a rapid increase in the tensile strength of the samples at early pavement ages.

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Articles in Press, Accepted Manuscript
Available Online from 08 February 2025
  • Receive Date: 13 September 2024
  • Revise Date: 06 February 2025
  • Accept Date: 08 February 2025