橡胶沥青性能测试技术的应用

Application of rubber asphalt performance test technology

本文通过调查研究国内外评价橡胶沥青的常规技术指标体系,室内采用8种不同基质沥青制备橡胶沥青,基于国内外规范中的针入度、锥入度、延度、软化点、弹性恢复、回弹恢复、Brookfield旋转黏度及剪切流变(DSR)试验等对橡胶沥青性能进行了评价,重点分析基质沥青四组分与各检测指标之间的相关性。研究表明:橡胶粉的溶胀作用不充分会导致针入度和延度的试验结果误差较大,针入度和延度指标评价橡胶沥青缺乏科学性;小锥小皿试验数据稳定性较强,能够有效评价橡胶沥青抗剪切流变性能;回弹恢复能够有效评价橡胶沥青在较小变形范围内的弹性恢复能力;橡胶沥青线弹性范围确定为20%~30%;基于DSR试验进行的应变扫描试验、温度扫描试验、频率扫描试验和滞回环试验等够显著区分橡胶粉与基质沥青的配伍性,由重复蠕变试验测得的零剪切黏度(ZSV)能够合理评价橡胶沥青高温性能;采用多变量回归分析和灰色关联分别评价基质沥青四组分与各项性能指标间的相关性,其中沥青质和饱和分关联程度较高;60℃车辙因子与基质沥青四组分的相关系数达0.900,60℃复数弹性模量和ZSV与基质沥青四组分的相关系数高达0.9999和1.0。

Through investigating and studying the conventional technology index system of the rubber asphalt evaluation at home and abroad,the interior 8 different matrix asphalts were adopted to prepare rubber asphalts.Based on the domestic and foreign penetration,cone into the degree of specification,ductility,softening point,elastic recovery,rebound recovery,Brookfield revolving viscosity and dynamic shear rheological（DSR）test,the rubber asphalt performance was evaluated,focusing on analyzing the correlation between the matrix asphalt four components and the detection index.The study shows that the insufficiency of the rubber powder swelling effect can lead to a large error in the test results of the penetration degree and delay.The small cone test data is very stable and can effectively evaluate the shear rheological properties of rubber asphalt.Rebound recovery can effectively evaluate the elastic recovery ability of rubber asphalt in the lower deformation range.The elastic range of rubber asphalt is deter-mined to be 20%-30%.Based on DSR tests such as strain scan test,temperature scanning test,frequency scanning test and hysteresis loop back test,the rubber powder and asphalt matrix compatibility can be significant enough to distinguish.The zero shear viscosity（ZSV）made by repeated creep test can reasonably evaluate the high temperature performance of rubber asphalt.Multivariate regression analysis and grey correlation were used to evaluate the correlation between the four components and the performance indexes of the matrix asphalt,with a high degree of asphalt and saturation.The correlation coefficient of 60℃ rut factor and the matrix asphalt four components is0.900.The correlation coefficient of the 60℃ complex elasticity modulus and ZSV and matrix asphalt four components are 0.9999 and 1.0,respectively.