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

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• Temperature - Although binder hardening occurs at roomtemperature 2, 14 , a higher temperature during contact between thebinder and the solvent results in a greater hardening effect 2, 10, 17 .Extraction method ASTM D2172 (Method B) employs a highertemperature than ASTM D2172 (Method A);• Light - The absence of light during contact between the binder and thesolvent reduces the hardening effect 2, 18 . RILEM Technical CommitteeTC 5611 has recommended that extracted binder solution be kept inthe dark until the recovery is completed;• Oxygen - A lower partial pressure of oxygen during contact betweenthe binder and the solvent reduces the hardening effect 2 ;• Different binder-aggregate types exhibit different extents of binderhardening for the same extraction and recovery conditions 2 .Conclusions regarding the effects of binder hardening imply that• The lowest possible temperature should be employed during theextraction-recovery phase, i.e. the hot extraction method, ASTMD2172 (Method B), and the high temperature Abson recoverydistillation, ASTM D1856, would be disadvantageous from a binderhardening perspective;• The time of contact between solvent and binder should be limited tothe shortest possible time that allows for effective extraction of thebinder from the hot mix asphalt.Incomplete removal of the solvent from the recovered binderResidual solvent remaining in the recovered binder after solventrecovery results in a reduced stiffness for the recovered binder.The presence and concentration of residual solvent in the bindercan be monitored using:• Infrared spectroscopy 9, 19 ;• Gas chromatography 20 ;• High performance liquid chromatography.Some researchers 14, 21 have shown that the Abson distillation(ASTM D1856) results in greater quantities of residual solventpresent in the recovered binder compared to the Rotavapor20
method (ASTM D5404). Other researchers 22 , however, usingdifferent solvent/binder systems, have found no differenceregarding residual solvents between the two methods. The initialperception has resulted in the Rotavapor method becoming themethod of choice since the 1970s, regardless of the fact that thismethod has also been shown to have lower repeatability. (Theease of the method and the lower recovery temperature have alsoplayed a role in the popularity of this method.)Incomplete removal of all the binder from the aggregateA number of researchers 9, 10, 21, 23 have shown that the binder isnever completely removed from the aggregate, regardless of thesolvent used for extraction.The solvent most widely recognised as having the highestsolvency power (especially for aged binder) is pyridine10, which ishighly toxic. An estimate of the binder retained by the aggregateduring extraction by any specific solvent can be ascertained bycomparing the results obtained for that solvent with resultsobtained for pyridine. Incomplete extraction causes the bindercontent of hot mix asphalt to be underestimated by 0,1 to 1,0% 2, 21, 23 .Extraction method ASTM D2172 (Method B) - hot reflux extraction- has been associated with less complete removal of the binderfrom the aggregate compared to ASTM D2172 (Method A) - coldcentrifuge extraction.The binder retained by the aggregate (after extraction) can eitherbe highly oxidised (aged) resulting in the polar fractions beingstrongly associated with the aggregate 10 (adsorbed), or theretained binder can be of low viscosity, having been absorbed by aporous aggregate 23 . Depending on the nature of the retainedbinder, incorporation of this fraction into the recovered binder canhave a significant effect on the recovered binder properties 10, 23 .Itappears that not much work has been done to determine theeffects of adding strongly ad/absorbed material back to therecovered binder. However, there are some 23 who argue that thead/absorbed binder remaining after extraction should not beregarded as part of the binder because of its close association with21
Page 1: Guide to the safe handling ofsolven
Page 4 and 5: Sabita DVD SeriesDVD100DVD200DVD300
Page 6 and 7: CONTENTS1. Introduction2. Solvent s
Page 8 and 9: • The use of High Performance Liq
Page 10 and 11: 2. Solvent specific test methods2.1
Page 12 and 13: • A mass balance requires a tempe
Page 14 and 15: *Jojoba oil (pronounced “ho-HO-ba
Page 16 and 17: properties of the recovered binder.
Page 18 and 19: Table 1. Coefficients of variationM
Page 23 and 24: • Density - In general, a solvent
Page 25 and 26: 2.5. The determination of the softe
Page 27 and 28: 4. Evaluating the cost-effectivenes
Page 29 and 30: 6. Conclusions and recommendationsT
Page 31 and 32: absorptive limestone). In this way
Page 33 and 34: 13. Peterson, GD, Davison, RR, Glov
Page 35 and 36: in a location close to where the pr
Page 37 and 38: product identifier (product name);
Page 39 and 40: eye wash bottles and safety showers
Page 41 and 42: • reaction to naturally-occurring
Page 43 and 44: consulting the MSDS for the product
Page 45 and 46: those which could compromise an ind
Page 47 and 48: • Reactive chemicals May be sensi
Page 49 and 50: The following guidelines should be
Page 51 and 52: mercury air concentrations. If a la
Page 53 and 54: Be prepared to repeat the process i
Page 55 and 56: Leaking regulators, cylinder valves
Page 57 and 58: Peroxide-forming (e.g. ether) and e
Page 59 and 60: • Direct connections: Direct conn
Page 61 and 62: This guide is available on the UK H
Page 63 and 64: Factors that can increase the risk
Page 65 and 66: containers that may be contaminated
Page 67 and 68: Record each run in a logbook: keep
Page 69 and 70: • Gas chromatographs (GC): Gas ch
Page 71 and 72:
Locate and know how to test and ope
Page 73 and 74:
Do not remove a dressing that has b
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As soon as the flames are extinguis
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Appendix B - Recommendations for so
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• All packages in storage should
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Table 2.Examples of incompatible co
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Table 3. Suggested segregation for
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• Keep picric acid solutions wet
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peroxides. The radius shall be meas
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acute health effect - an effect tha
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8 Corrosive; 9 Miscellaneous.ED50 (
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freezing point - the temperature at
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airborne substance, averaged over a
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teratogen - chemical which may caus
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• Many of the occupation exposure
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