Microscopic reaction process of cement with asphalt emulsion and its influence on macroscopic properties of binder

Abstract

This research aimed at studying the reaction process between cement and asphalt emulsion from a microscopic view and the variations of macroscopic properties with cured time. The microstructure of cement asphalt emulsion (CAE) with a mass ratio of cement to asphalt (C/A) of 0.6 was scanned with scanning electron microscope (SEM) and its functional groups were measured with Fourier-transform infrared spectrometer (FTIR) after being cured for 7 days. Six CAEs with different C/A ratios were prepared and cured for different days, then DSR tests and beam bend rheometer (BBR) tests were conducted to evaluate their macroscopic performance. The results indicated that emulsion residue was relatively porous. Hydration reaction occurred between cement and water secreted by demulsification of asphalt emulsion, hydrates would gradually fill the voids. Asphalt and hydrates were interrelated into a cross-linking structure. As the rigidity of hydrates increased with cured time, the rutting resistance of CAE was improved, but its low-temperature performance and fatigue resistance were reduced.