Study on high temperature rheological properties of toughened waterborne epoxy resin-emulsified asphalt for adhesive layer materials in thin layer overlay technology

The purpose of this study is to prepare a waterborne epoxy resin emulsified asphalt with better high temperature rheological properties as a tack coat material for thin-layer overlay technology. Therefore, styrene-butadiene rubber (SBR), styrene-butadiene-styrene (SBS) and polysulfone (PSF) with the content of 2%, 4% and 6% were selected to modify and toughen waterborne epoxy resin emulsified asphalt (EA-WER) with the content of 7.5% of waterborne epoxy resin (WER). The dynamic shear rheological test (including temperature scanning test and frequency scanning test) and fluorescence microscope test were carried out to systematically evaluate its rheological properties. The results show that the addition of three toughening agents improves the high temperature deformation resistance of EA-WER, among which SBS waterborne epoxy resin emulsified asphalt (EA-SBS-WER) is the best, SBR waterborne epoxy resin emulsified asphalt (EA-SBR-WER) is the second, and PSF waterborne epoxy resin emulsified asphalt (EA-PSF-WER) has the smallest relative improvement. The optimum content of SBS is 6%, and the optimum content of SBR and PSF is 4%. The fitted main curve further confirms the optimal dosage.