NEXCEL Ph.D student ZHANG Junjie & YANG Bin gave presentations on WTC2024

Time: 2024/07/29 Publisher： oiginal Views：

Introduction

On June 26-29, 2024, The World Transportation Convention 2024 (WTC2024), co-hosted by six institutions including the China Highway & Transportation Society, was successfully held in Qingdao, China. Under the theme of “New Transportation in Change”, the WTC2024 attracted thousands of representatives from academia and industry in China and abroad to discuss innovation and development in the field of transportation. Mr. Zhang Junjie from Harbin Institute of Technology and Mr. Yang Bin from the Hong Kong Polytechnic University, Principal Investigators of NEXCEL 2024 PHD projects attended and delivered presentations at the conference.

ZHANG JUNJIE

Zhang Junjie from Harbin Institute of Technology, Principal Investigator of NEXCEL 2024 PHD project ‘Research on the Composite Aging Mechanism and Phase Structure of SBS-Modified Asphalt Multiphase Systems,’ delivered a presentation titled 'Quantitative Characterization of the Blending and Diffusion of Virgin and Reclaimed Asphalt in Recycled Asphalt Mixtures.’ He introduced a new method using wooden cubes and 3D fluorescence imaging technology.

The results showed that this method could achieve three-dimensional characterization of the fusion state of new and old asphalt, providing valuable parameters for distinguishing fusion and diffusion processes. Temperature, rather than curing time, was found to be crucial for fusion, and smaller aggregate sizes improved the activity of recycled asphalt. This research offers theoretical guidance for the design and precise recycling of recycled asphalt mixtures.

Mr. Yang Bin from the Hong Kong Polytechnic University, the Principal Investigator of NEXCEL 2024 PHD project ‘Preventive Maintenance Material Design and Multiscale Characterization of its Working Mechanism for Porous Asphalt Pavement', delivered a presentation titled 'Characterization of Diffusion of Surface Treatment Emulsion in Aged Asphalt Binder of Porous Asphalt Mixture through SEM/EDS Analysis'.

To investigate the potential diffusion phenomenon of surface treatment emulsion residues in old porous asphalt (PA) mixtures, this study used nano titanium dioxide powder as a tracer to mark the new asphalt in the emulsion. The scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) were used to track and investigate the diffusion behavior of emulsion residues in the old asphalt over a long curing period.

This study provided a new perspective for directly observing the potential diffusion behavior between new and old asphalt binders within a mixture. It also revealed the diffusion laws of emulsion residues in old asphalt binders at actual service temperatures, laying a technical foundation for optimizing the design of the preventive maintenance material. This study was also highly recognized by the attendees.