Member input shaping revisions to PMB standard
Member input was used by our Technical Committee, TF Specifications and TF Data Collection, which all carefully reviewed the draft and together developed Eurobitume positions (summarised below) on key aspects of the revised draft standard.
- Softening Point Ring and Ball (SP RaB): maintain SP RaB for PMB for the time being and introduce DSR temperature sweep on fresh binders for SP RaB´s replacement at the next revision.
- Needle penetration: retain the penetration ranges for the time being, but check whether overlaps should be maintained before the next revision.
- Elastic Recovery: maintain elastic recovery for the time being and check whether e.g. % Recovery in MSCRT is suitable as a replacement at the next revision.
- MSCRT testing: conduct only on short-term aged binders, and at different, given temperatures (e.g. 45, 60, 75 °C), depending on the PMB and its application.
- BBR testing: address (T (S = 300 MPa) and corresponding m-value) on long-term aged PMBs.
- BBR calculations: use logarithmic interpolation for calculations referring to stiffness, S, and linear interpolation for calculations referring to m-value; for m-value related calculations, extrapolation might be possible.
Equi-stiffness temperature: should be addressed by T (G* = 15 kPa) and respective phase angle. These positions were shared as “suggestions” by Eurobitume members with their National Standardisation Body (NSB) mirror committees and formed part of the final decision-making process.
All NSB input will then be reviewed, discussed and accepted, or not, before a final draft of the standard is submitted for Formal Vote by the CEN members, which is expected to be in late 2021 or early 2022.