Adhesion of Bituminous Crack Sealants to Aggregates Using Surface Energy Theory

Abstract

In the system formed by bituminous crack sealant and the crack wall, the contact area of aggregate and sealant is maximum, and types and properties of aggregate have an obvious influence on the adhesion of the sealant. To quantitatively evaluate the adhesion of sealant to aggregate, based on the surface energy theory, the surface energy and its components of sealant and aggregate were determined and calculated using the sessile drop method. Then, the adhesion work of different types of sealants and aggregates was calculated. The correlation of adhesion work was verified by the improved boiling method test and scanning electron microscope (SEM) test. Results show that surface energy of the aggregate is obviously higher than that of the sealant. The relationship of surface energy of raw materials is granite>diabase>basalt>Sealant A (type JG-10; Beijing Jiageweiye Company) > Sealant C (type II; American Crafco Company) > Sealant B (type JSD; JSD Corporation of Japan). The relationship of adhesion work of different sealants with the same aggregate is Sealant A > Sealant C > Sealant B, indicating that the adhesion of Sealant A to aggregate is better than that of Sealant B and Sealant C. Results of the improved boiling method test show that the coefficient of linear correlation between the mass loss rate of sealant and the adhesion work is as high as 0.9308, indicating that there is a good linear relationship between them. The SEM results show that the adhesion work is consistent with the actual adhesion state of the interface, which shows that the adhesion work index can be used to characterize the adhesion of sealant to aggregate.