Blackpole Business Centre, Worcester WR3 8SQ

Asphix™ antistripping agents

High performance, heat stable additives formulated to significantly enhance the adhesion between a wide range of bitumen and aggregate combinations. 

Adhesion promotion between bitumen and the aggregates used in asphalts is essential in producing durable materials that perform as expected. It is well known that the bitumen bond to certain aggregates can be quite poor which could potentially lead to early material failure. It is therefore important that an anti-stripping agent like Asphix™ is used in order to improve the aggregate to bitumen bond and the materials overall performance. Asphix™ has been shown to work in practice with a variety of aggregate types and improve durability for a variety of mixtures.

The EN12697-11(C) Boiling Water Stripping Test is an aggressive, objective adhesion test with good precision that can be used across a variety of aggregate types. This test was chosen to show the improvement that Asphix™ makes to an aggregate that is exhibiting considerable stripping during this procedure. These results show that Asphix™ offers at least five times improvement over an untreated sample.

Applications for Asphix™

  • Hot Mix Asphalt (HMA)
  • Warm Mix Asphalt (WMA)
  • Cold Mix Asphalt 
  • Can be used with a variety of WMA systems (such as foam and additives) to enhance bitumen-aggregate adhesion at temperatures between (90-140ºC).
  • Co-Emulsifier for Bitumen Emulsions 
  • Used to improve stability and storage at higher temperatures, and also provide a more consistent and uniform spray during application of surface dressing binders.

Benefits of Asphix™

Asphix™ can be

  • Added to hot bitumen in storage
  • Dosed into the bitumen weigh kettle
  • Added directly into the mixer
  • Dosed into the bitumen feed line of continuous plants.

Effective when used with Foam-mix systems to extend foam life and improve Reclaimed Asphalt Pavement (RAP) to bitumen adhesion.

Promotes adhesion between bitumen and aggregates at typical HMA temperatures (140-180ºC). Heat stable in hot bitumen. Can be stored at high temperatures and not lose activity.

Features of Asphix™

Dosage of both Asphix™ and Asphix™ L is 0.1–1.25% (weight of bitumen) depending upon the application.

Asphix™ offers at least five times improvement over an untreated sample.


  • Asphix™ is a dark paste that needs heating to 50-70ºC in order to pump it
  • Asphix™ L is a liquid that can be pumped down to approximately -10ºC
  • Asphix™ and Asphix™ L should be dosed into bitumen between 100-190ºC