浇注式沥青混凝土介电特性研究

Research on Dielectric Characteristic of Guss Asphalt Concrete

对铺筑于钢桥的浇注式沥青混凝土(Guss)进行钻芯试验,将会造成钢桥桥面损坏及留下侵害的弱面,须以无损检测方法,进行路面质量控制。以电磁波原理应用于无损检测过程中,介电常数为影响电磁波行为的重要参数,研究使用网络分析仪搭配终端开路同轴探棒,量测Guss胶浆,粒料,和Guss试件的介电常数,以2.55GHz频率的介电常数数值探讨孔隙率,密度,以及温度变化对于介电常数的影响。另发展Guss沥青混凝土介电混合模型与介电常数预测密度模型,并且使用无核密度仪Pave Tracker量测Guss沥青混凝土密度,并以校正后的Pave Tracker数值与实验室密度加以比较。试验结果显示孔隙率和密度与介电常数呈线性关系,R2约为0.6。在温度量测范围90℃至60℃的降温过程当中,Guss试件介电常数随温度下降而减少。另由本研究所发展的Guss试件介电混合模型,以胶浆,粒料,石粉和空气的介电常数及所占的体积百分比,可推测Guss试件的介电常数。并且由所建立的密度预测模型,以Guss试件介电常数预测密度,密度预测值与实验室密度的相关性R2为0.78。最后以校正无核密度仪Pave Tracker读数,校正后Pave Tracker读数与实验室密度的相关系数R2为0.89。

Pouring type of paving Gangqiao（Guss）asphalt concrete core experiment was carried out,will cause damage of steel bridge deck and left of the weak side,NDT methods,should be related to quality control in pavement.To the electromagnetic principle applied to nondestructive testing process,dielectric constant as the important parameters influencing the electromagnetic wave behavior,this study using network analyzer with terminal open coaxial rod,measuring Guss mucilage,aggregate,and Guss specimen of dielectric constant,dielectric constant of 2.55 GHz numerical study porosity,density,and the effects of temperature on dielectric constant.Another development of Guss asphalt concrete density of dielectric constant and dielectric mixture model prediction model,and using the magnetic density meter PaveTracker density measurement of Guss asphalt concrete,and adjusted the PaveTracker numerical density compared with laboratory.Experimental results show that the porosity and density and dielectric constant linear relationship,R2 is about 0.6.In the temperature measurement range of 90 ℃ and 60 ℃ and cooling process of Guss specimen dielectric constants decrease with temperature drop.The other by our institute＇s development of Guss specimen dielectric hybrid model,mucilage,aggregate,powder and percentage of dielectric constant and the volume of the air,can be speculated that Guss dielectric constant of the specimens.And established by the density of the forecasting model,to predict the density Guss specimen dielectric constant and density of the correlation of predicted values and the density of laboratory R^2 of 0.78.Finally by magnetic density correction instrument PaveTracker readings,adjusted PaveTracker readings with lab density correlation coefficient R^2 is 0.89.