Abstract: Through testing the hardness, tensile property and adhesive tensile property of PTN bitumen polyurethane joint materials with three different mix ratios at temperature from 20℃ to -100℃, we studied cryogenic performance of PTN material (consisting of component A and component B) under ultra-low temperature. Images magnified 5000 times were observed and analyzed by using scanning electron microscope (SEM). On the basis of this, the relationship between hardness and tensile performance was established to predict tensile performance of PTN material by non-destructive inspection method. Test results show that: 1) as component B increases, the hardness and the tensile strength decreases, whereas the elongation at break increases; 2)under given mix proportion, hardness and tensile strength increase with the decrease of temperature, but the elongation at break decreases; 3)at temperature below -60 ℃, hardness, tensile strength and elongation at break no longer vary with temperature, in other words, stagnation appears; 4)tensile bonding strength increases first and then decreases when temperature reduces, whereas adhesive tensile elongation at break decreases with the decrease of temperature until zero value occurrs at ultra-low temperature.

Key words: PTN bitumen polyurethane joint materials, cryogenic performance, SEM(scanning electron microscope), strength prediction model, elongation at break, tensile strength