Testing for Performance Specification of Asphalt Binders (M1-A)

IPL has worked with NZTA, suppliers and customers to gain a good understanding of this new specification and have expanded their Bitumen testing capabilities to meet the suppliers and customers M1-A testing requirements.

The M1-A specification sets out the performance characteristics to be met by the binders used for asphalt manufacture. It supersedes the previous M1 specification which was based around the measurement of penetration and basic viscosity. Premature shoving and rutting of our roads has shown that these measures are insufficient to ensure asphalt performance in heavy traffic and high temperature conditions hence the decision to adopt the performance based M1-A specifications.

The M1-A performance specification of asphalt binders sets out four different performance levels which will vary depending on the traffic level and the traffic speed range. The specification addresses the need to predict binder performance in asphalt, therefore lowering the risk of premature ageing of our roads.

IPL attended rheology training and planning to allow for the development of bitumen testing to M1-A specifications. The Northland lab was also refurbished to convert existing lab space to house the equipment, HSNO and testing requirements set out by the test methods. Analysis to M1-A testing requirements began on the 1st of July 2018. The testing provided by IPL is part of our customers’ Quality Assurance plan to ensure that the bitumen manufactured or imported into NZ complies with the M1-A specs. The testing developed includes:

- ASTM D2872 - Rolling Thin Film Over Test

- AASHTO T315 - Rheology of Asphalt and Bitumen by DSR

- AASHTO T350 - Dynamic Shear Rheometer