沥青材料粘弹性对地板隔震系统固有频率的影响

Influence of viscoelasticity of asphalt on the natural frequency of floor shock isolation systems

研制地下工事沥青隔震垫的关键问题是配制出具有一定粘弹性质的沥青材料，因此，研究沥青改性方法、沥青粘弹性质与沥青隔震垫地板隔震系统固有频率的关系具有重要意义。本文提出了采用沥青材料动弹模量计算地板隔震系统固有频率的方法。采用该方法可方便地求得地板隔震系统固有频率，计算结果接近实测值。研究了热塑性嵌段共聚物、增塑剂、丁苯橡胶、树脂和交联剂等对沥青材料动弹模量的影响，结果表明：增塑剂和热塑性嵌段共聚物可大幅度降低沥青材料的动弹模量及其频率敏感性，从而降低系统的固有频率。

The preparation of an asphalt material with certain viscoelasticity is a key point in the development of the asphalt shock isolation layer used in underground works. Therefore, it is very important to explore the relationship between the asphalt modification, the visco-elastic property of asphalt and the natural frequency of the floor shock isolation system. A method is proposed in this paper, which can calculate the natural frequency of the floor shock isolation system easily by means of the dynamic elastic modulus of the asphalt, and which yields results close to the actual measurements. The influence of plastieizers, thermoplastic block copolymer, styrene-butadience rubber, resin and cross linkers on the dynamic elastic modulus of the asphalt is also researched. The results show that the plasticizers and thermoplastic block copolymer can reduce the dynamic elastic modulus of the asphalt and its sensibility to different frequencies to a great extent. As a result, the natural frequency of the floor shock isolation system can be decreased.