端部效应对沥青混合料粘弹力学特性测试结果的影响

Effects of End Friction on Asphalt Mixture Viscoelastic Mechanical Properties Testing

端部效应会影响沥青混合料粘弹力学特性测试的结果.开展了聚四氟乙烯膜、橡胶膜涂硅油、双层PP膜夹滑石粉层共3种端部效应消减措施下动态模量试验和重复剪切流动试验,分析不同消减措施对动态模量和流动剪切速率数据影响;使用0.25,0.5,1.5mm共3种厚度聚四氟乙烯膜进行动态模量测试,分析聚四氟乙烯膜厚度对动态模量的影响.结论显示,消减措施的施加会在总体上减小动态模量测试值,且频率越小,减幅越高;聚四氟乙烯膜厚度越大,动态模量试验结果变异系数越小.采用端部效应消减措施,会使试件剪切流动速率变大.

Asphalt mixture viscoelastic mechanical properties testing results depend on the effects of end friction.Dynamic modulus tests and repeated shearing flow tests are conducted for three types of end friction reducers that are Teflon,latex membranes pasted by silicone oil and PP membranes pasted by tale powder.The effects of different reducers on dynamic modulus tests and repeated shearing flow tests are analyzed.The effects of Teflon thickness on dynamic modulus are investigated for three thicknesses：0.25 mm,0.5mm and 1.5mm.Results show that the application of reducer reduces the dynamic modulus testing results and this effect enhances as loading frequencies become lower.In addition,lower coefficient of variation（COV）results can be achieved for thicker Teflon.Besides,the application of end friction reducer could increase the shearing flow slope.