基于宏观性能与微观性状确定SBR胶乳在SBR改性乳化沥青中的最佳添加量

为确定路用拌和型SBR改性乳化沥青中SBR胶乳的合理添加量,对不同SBR胶乳添加量改性乳化沥青进行了基本性能指标测试与对比。实验结果表明,随着SBR胶乳含量的增加,SBR改性乳化沥青粘度增加、与集料的粘附性提高,但储存5天后的稳定性下降。对不同胶乳含量的SBR改性乳化沥青进行电镜扫描发现,SBR胶乳含量为3%时,胶乳以小而密的颗粒存在于乳化沥青中,与乳化沥青接触面积最大,溶解度最大。分析不同胶乳含量SBR改性乳化沥青DSC曲线发现:胶乳含量在3~3.5%之间时,SBR改性乳化沥青内能较小,组分更宜稳定,不易发生离析现象。考虑以上实验结果并结合不同胶乳含量SBR改性乳化沥青蒸发残留物的三大指标和实验结果,同时考虑技术和经济因素,认为SBR改性剂添加量在3~3.5%之间时,生产的改性乳化沥青既经济又具有较好的性能指标。

Determination of Optimum SBR Latex Content in SBR Modified Asphalt Emulsion Based on Macro and Micro Characters

There exists an optimum SBR latex content in SBR modified asphalt emulsion as far as the emulsion property is concerned.Through a comparison of performance among SBR modified asphalt emulsions with different SBR latex contents,a more reasonable latex content range was recommended.In addition to penetration,softening point and ductility of the emulsion evaporated residue other properties as viscosity,5d storage stability and micro characteristics of the emulsion were investigated.Viscosity tests showed that the viscosity of SBR modified asphalt emulsions increased with the increase in SBR latex content,w hile the 5d storage stability of that decreased with the content.Electron microscopic scanning shows that SBR latex dispersed densely in asphalt emulsion as small droplets at a latex content of 3%,indicating the largest contact area and solubility.DSC curve show s that SBR modified asphalt emulsion had the minimum internal energy and thus a more stable composition when the latex content ranged between 3%-3.5%.Combining softening point, penetration and ductility test results of the emulsion evaporated residue,an optimum latex content of 3%-3.5%was recommended when considering both technique properties and cost.The research provides a method better determining SBR latex content in SBR modified asphalt emulsion.