Assessment of a Sessile Drop Device and a New Testing Approach Measuring Contact Angles on Aggregates and Asphalt Binders: Fid-Bau Portal

Assessment of a Sessile Drop Device and a New Testing Approach Measuring Contact Angles on Aggregates and Asphalt Binders

Koc, Murat / Bulut, Rifat

Abstract

Moisture damage in asphalt pavements can produce rapid failures costing millions of dollars to repair. Surface energy interactions between the asphalt binder and aggregate are known as the fundamental approaches to predicting the mechanisms in the moisture damage process in asphalt mixes. The field of surface energy measurement and its application for moisture damage evaluation is very recent and in the developing stages. The current practice involves two testing equipment for surface energy measurements of asphalt binders and aggregates. The Wilhelmy plate (WP) device is usually employed for surface energy measurements of asphalt binders, and the universal sorption device (USD) is usually used for surface energy measurements of aggregates. This paper presents a sessile drop (SD) device that can be employed for measuring the surface energy components of both binders and aggregates. The SD device has been used for measuring contact angles directly on asphalt binder and aggregate surfaces. The surface energy components of aggregates and binders are calculated using the measured contact angles. The laboratory contact angle measurements on aggregate specimens indicate that while the results from the device are in agreement with the results in the literature, they are not in agreement with the results from the USD. The surface energy components of asphalt binder determined from the measurements of contact angles using the SD device and from the WP measurements are in close agreement.