通过对PTN石油沥青聚氨酯接缝材料从20℃至-100℃的硬度、拉伸性能、拉伸粘结性能的测试,研究PTN材料在超低温下的性能,用扫描电镜(SEM)观察到样品放大5 000倍的样貌,对材料微观形貌上进行分析,建立硬度与拉伸性能的相关关系式,可用于以无损检测方法预测PTN材料拉伸性能。试验结果表明:PTN材料的硬度、拉伸强度随着乙组分含量增加而降低,断裂伸长率则增大。在同样配比下,硬度、拉伸强度随着温度降低而增大,断裂伸长率减小,在超低温-60 ℃以下,硬度、拉伸强度和断裂伸长率不再随温度变化,出现“停滞”现象。拉伸粘结的强度随着温度先增加后减少,拉伸粘结的断裂伸长率一直减少,至超低温下出现“0值”现象。

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.