Numerical analysis of mechanical properties at the internal interface of SFP material using a digital image algorithm

Semi-flexible pavements (SFP) are extensively used in high-traffic zones owing to their outstanding resistance against rutting. Nonetheless, interface cracking persists as a prominent issue within SFP composites. This study establishes a finite element model of SFP using a computer vision algorithm to analyze its mechanical properties at the internal interface. Two interface components, namely the aggregate-asphalt and asphalt-grout interfaces, were developed to simulate stress distribution, crack initiation, and extension within the multiphase composite of SFP. The examination of transition zone properties within the asphalt-grout interface shed light on damage morphology and mechanical response. The results demonstrate that incorporating the interface layer significantly enhances the accuracy of force behavior analysis in simulating SFP materials. Furthermore, reinforcing the interface transition zone boosts the overall peak compressive strain strength of SFP materials in tandem with increased interface strength. Moreover, the grout joints and asphalt-grout interfaces within SFP act as vulnerable points where cracks propagate swiftly, leading to the detachment of cementitious grout from the base asphalt mixture.