Guide to the safe handling of solvents in a bituminous ... - Aapaq.org

• Density - In general, a solvent with a higher density would tend toretain more fines, which would contaminate the recovered binder,resulting in stiffer properties being attained;• Boiling point - A solvent with a higher boiling point tends to result inthe less efficient removal of the solvent from the binder during therecovery process, resulting in softer properties being measured.2.1.4 Experimental case studies: Peterson et al 21 studied the effectsof solvent on recovered binder properties using a modified AASHTOT319/Rotavapor (ASTM D5405) as extraction/recovery process. They couldfind no differences between the technical performances for TCE, EnSolvand toluene/ethanol using G*/Sin as the defining parameter. Theintra-laboratory coefficient of variation for G*/Sin was 26%. Such arelatively high value would limit the validity of any conclusions drawn fromthe study.Collins-Garcia et al 8, 24 studied the effects of solvent on recovered binderproperties using a modified Reflux (ASTM D2172 (Method B))/Rotavapor(ASTM D5405) as extraction/recovery process. They could find nodifferences between the technical performances for TCE and EnSolv usingBrookefield viscosity at 60 o C and penetration as the defining parameters.Stroup-Gardiner et al 9 studied the effects of solvent on recovered binderproperties using the centrifuge method (ASTM D2172 (MethodA))/Rotavapor (ASTM D5405) as extraction/recovery process. They usedsix combinations of different grades of binders (including a SBS-modifiedbinder) and aggregates. They could find no differences between thetechnical performances for TCE and four nPBs (Lenium, Leksol,Hypersolve, Ensolv) using G*/Sin and BBR Stiffness as the definingparameters. When the Hypersolve solvent was used, the SBS polymerseparated from the binder in solution. Intra-laboratory coefficient of variationfor G*/Sin varied from 25% to 65%, severely compromising the validity ofconclusions drawn from the study.Van Assen 20 studied the effects of solvent on recovered binder propertiesusing the centrifuge method (ASTM D2172 (Method A))/Abson distillationrecovery (ASTM D1856). Results indicated that for South African bindersand aggregates, good technical performance was obtained when usingbenzene and toluene as solvents. However, results for very aged asphalt23