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

Abstract

<jats:p> 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 SEM and its functional groups were measured with 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 BBR tests were conducted to evaluate their macroscopic performance. The results indicated that emulsion residue was relative 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. </jats:p>

Assessment of Interaction Behaviors of Cement-Emulsified Asphalt Based on Micro-Morphological and Macro-Rheological Approaches

“…Besides, the absorption peaks of Si–O bond and C=O double bond in CO 3 2− of cement powder are also observed in the similar position. It is worth mentioning that the absorption peaks at 1111 cm −1 and 1026 cm −1 in CEACB denote the ettringite (AFt) and the calcium silicate hydrate (C–S–H), respectively, which mainly derive from the new groups of SiO 3 2− generated by the hydration of cement [ 40 ]. The above observations are consistent with the references [ 41 , 42 ].…”

“…Tian et al [ 39 ] adopted the elastic modulus to estimate the influence of A/C ratio on the formation of complicated microstructure of cement asphalt emulsion generated by both cement hydrates and asphalt agglomerates. Tian et al [ 40 ] analyzed the strength development of cement hydration products during the process of asphalt emulsion demulsification by utilizing the complex modulus of CEACB. Ding et al [ 14 ] applied the creep curves and the storage modulus mater curves to distinguish the mechanical properties of CEACB under the condition of different A/C ratios, determining it as viscoelastic solid material or viscoelastic fluid material.…”