Enhancement of curing properties of cold in-place recycling asphalt mixtures by induction heating

In this study, samples of cold in-place recycling mix (CIR) with steel fibres were manufactured and heated by electromagnetic induction. Heating was conducted to accelerate the curing process and make the CIR mixtures more competitive against other less-sustainable road materials. Heating can also be applied after years of service life to reduce the viscosity of the binder and make it flow through cracks, healing damage. Cylindrical Marshall samples were heated by induction for different durations immediately after production and their mechanical performance was assessed over different curing periods. In addition, 3-point bending healing tests were carried out on cured semicircular samples. The results showed that the remaining water content in samples heated for 180 s was lower than in control samples (not heated) after 21 days. The Marshall stability and flow after compaction increased by 147% and 144%, respectively, when heating was applied for 240 s. Healing tests produced encouraging results with strength recoveries higher than 50%.

Automated summary

In this study, cold in-place recycling mix with steel fibers was heated by electromagnetic induction to accelerate curing process and improve competitiveness. The results showed significant improvements in Marshall stability, flow after compaction, and strength recovery rate in healing tests after heating.