Impact of freeze-thaw environment on concrete materials in two-lift concrete pavement

Abstract

The freeze-thaw (FT) damage is a potential severe distress on concrete pavements in seasonal frozen regions. This study focuses on the FT resistance of a two-lift concrete (2LC) pavement, including a polypropylene fiber reinforced concrete (PFRC) top lift and a conventional portland cement concrete (PCC) bottom lift. The rapid FT test was conducted on PCC, PFRC, and 2LC specimens and the relative dynamic modulus and mass loss were measured. The mechanical properties of concrete materials were investigated in laboratory, including compressive, tensile, flexural strengths, and flexural modulus. In the end, the influence of FT damages of concrete materials on pavement responses was evaluated. It is found that with the addition of the PF, the PFRC and the 2LC exhibited better mechanical properties and less mass loss than the PCC after FT cycles. The PFRC and the 2LC behaved better FT resistance than the PCC. The Voigt model can predict mechanical properties of 2LC in freeze-thaw process. Through pavement response analysis, the FT damage was found shortening the service life of 2LCP. In summary, the proposed 2LC pavement was justified a better alternate concrete pavement type on resisting the FT environment in seasonal frozen areas.