01557059

Component

Even though sealants are commonly used to insulate crack and joints preventing water from entering the underlying structure, extended exposure of sealants to water has shown to negatively impact sealants properties causing gradual degradation of its performance. However, sealants show different degradation rates when exposed to water depending on their chemical composition and environmental conditions. While there have been many studies on characterizing sealant performance in dry conditions, there has been no comprehensive experimental test to evaluate crack sealants' water susceptibility based on a fundamental material property. As such this paper investigates the effect of water exposure on three different crack sealants commonly used in cold, moderate and hot climates. It is hypothesized that water penetrates into the interface between crack sealant and substrates causing progressive adhesion failure and that the rate of failure varies depending on the sealant’s surface chemistry as related to its interaction with water molecules in different environmental conditions. Accordingly, this paper measures the change in a sealant’s adhesion strength and surface energy before and after water conditioning. To study adhesion strength and its change due to water conditioning, three different types of sealant were tested using Direct Adhesion Tester (DAT). It was found that the adhesion strength of all three crack sealants reduces due to water exposure. In addition, to evaluate the surface properties and water phobicity of each sealant, the contact angle between a droplet of water and sealant surface was measured before and after conditioning at different temperatures. The objective of the latter experiment was to determine whether sealants' susceptibility to water would vary with pavement surface temperature. To do so, a sessile drop method utilizing FTA-1000 was used to determine the contact angle for each of the aforementioned water-sealant pairs at different temperatures. The results obtained were further used to calculate the work of adhesion at each scenario to be correlated to mechanical adhesion strength measured with DAT.

This paper was sponsored by TRB committee AHD25 Sealants and Fillers for Joints and Cracks. Alternate title: Investigating Effects of Water Conditioning on the Adhesion Properties of Crack Sealant.

01550057

15-5935

English

15p

2015

Transportation Research Board 94th Annual Meeting

Digital/other

Figures; Photos; References; Tables

Adhesion; Adhesive strength; Pavement cracking; Pavement joints; Sealing compounds; Surface energy; Surface temperature

Moisture susceptibility

Highways; Materials; Pavements; I35: Miscellaneous Materials

Transportation Research Board Annual Meeting 2015 Paper #15-5935

TRIS, TRB, ATRI

Dec 30 2014 1:59PM