01697360

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Crack sealant is an effective, simple and extensive maintenance approach for repairing cracks all over the world. However, extended exposure of sealants to complex ambient conditions have shown to negative impact on sealants properties, causing gradual degradation of sealant performance even seriously premature failure during their service. According to fracture modes of the failure interface, it is found that the weak boundary layer indeed exists and results in adhesive failure of the crack sealant. This paper presented three harmful environmental factors, namely temperature, water and impurity, to investigate the effect of hostile ambient exposure on different crack sealants commonly used in hot and moderate climates. Tensile test was the main evaluation method and the Weak Boundary Layer (WBL) theory was introduced to illustrate the adhesion failure between sealant and crack wall. The analysis of the experimental results showed that the lower temperature, the longer soaking time and the impurities would precipitate the occurrence of weak boundary layer. Among which, sealant was in the glassy state and likely to arise brittle fracture at the interface at -30 °C. When soaking for a long time, sealant would become harden gradually, and water could penetrate into the pores on the adhesive surface of the crack wall. Impurities at the interface would hinder the adhesive and reduce the contact area between sealant and crack wall. So that the adhesion property between the interfaces would drop sharply and thus caused adhesion failure.

This paper was sponsored by TRB committee AHD25 Standing Committee on Sealants and Fillers for Joints and Cracks.

19-02052

English

9p

2019

Transportation Research Board 98th Annual Meeting

Digital/other

Figures; Photos; References; Tables

Adhesive strength; Boundary layer; Cracking; Sealing compounds; Tensile strength

Highways; Materials; Pavements

Transportation Research Board Annual Meeting 2019 Paper #19-02052

TRIS, TRB, ATRI

Dec 7 2018 9:25AM