冬季由于低温路面经常会被冰雪覆盖，融雪盐是对路面进行融雪化冰的主要方式之一。为了研究盐冻循环前后的基质沥青、SBS(苯乙烯-丁二烯-苯乙烯嵌段共聚物)改性沥青和胶粉改性沥青的细观结构和低温流变性能变化，利用 SEM 和弯曲梁流变仪(BBR)对其测试。结果表明：改性剂以特定的结构形态存在于沥青中，二者具有良好的相容性，这种形态可以更好地吸附沥青，提高沥青的低温弹性或韧性，进而改善了沥青的低温性能。盐冻循环破坏了沥青的结构，影响了沥青的低温抗裂性能。经历盐冻循环后沥青的蠕变劲度模量增大、蠕变速率减小，低温抗裂和应力松弛能力降低，但改性沥青低温性能总体上优于基质沥青。因此建议北方等寒冷地区尽量选用改性沥青作为路面材料。
In winter road pavements are frequently covered by ice and snow because of the low temperature.Dei-cing salt is one way to deal with the icing coverage and clean the pavements.The SEM and bending beam rheometer (BBR)were used to study microstructure and rheological properties at low temperature of three kinds of asphalts (matrix asphalt,SBS(polystyrene-polybutadiene-polystyrene)modified asphalt and rubber powder modified asphalt) before and after the salt freezing cycle.The results show that the modified agent exists in asphalt with specific struc-ture,and the two have good compatibility,which can adsorb asphalt better,so that the low temperature elasticity or viscosity of asphalt has been increased and then the low temperature performance of asphalt can been improved.Af-ter salt freezing cycle,the structure of asphalt has been damaged,which could affect the low temperature crack re-sistance of asphalt.The creep stiffness modulus of asphalt has been enlarged,and the creep strain rate of asphalt has been decreased after salt freezing cycle.As a result,the low temperature crack resistance and the stress relaxation a-bility have been reduced.However,the low temperature performance of modified asphalt is better than that of ma-trix asphalt.It is recommended that the north cold areas as far as possible choose modified asphalt as the pavement material.
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