Specifications for paving bitumens, in addition to tests to indicate contamination, should control deformation response over the whole temperature and rate of loading ranges encountered by the material in use, and also indicate its tendency to harden or otherwise deteriorate during handling and service. Deformation response from the highest handling temperature to the maximum pavement temperature is predominantly viscous and specification of viscosity limits at 70 and 130 deg C gives control of response in this temperature range. The simple assessment and specification of deformation response in the lower part of the service temperature range remains a problem but the effect of temperature can be assessed by a 'consistency' measurement in the lower part of this range. This could either be an 'apparent' viscosity measured on the sliding plate viscometer at 25 deg C, a penetration test at 15 deg C or the Frass brittle test. The California Rolling Film Oven test is preferred as a means of assessing hardening and deterioration in handling. Increase in viscosity at 60 or 70 deg C gives a measure of hardening and a low ductility after treatment gives an indication of either breakdown in the structure of the bitumen or of one with an unacceptably high temperature susceptibility in the service temperature range.
- Conference on the Efficient Use of Bitumens, Asphalts and Tars as Paving and Construction Materials, Sydney, Australia, 2-3 December 1974; Session 2.
University of New South WalesSchool of Civil Engineering, Anzac Parade
Kensington, New South Wales Australia 2033
- Dickinson, E J
- Publication Date: 1974-12
- Features: Appendices; Figures; References;
- Pagination: 17 p.
- TRT Terms: Asphalt; Bituminous materials; Bituminous pavements; Building materials; Concrete hardening; Consistency; Deformation; Deterioration; Hardness; Level of service; Loads; Materials management; Specifications; Tar; Temperature; Testing; Viscosity
- Uncontrolled Terms: Loading rate; Service
- Subject Areas: Highways; Materials;
- Accession Number: 00095558
- Record Type: Publication
- Files: TRIS
- Created Date: May 29 1975 12:00AM