Asphalt mixture testing device



Invention description

SHEAR1 is a significantly smaller and cheaper alternative for testing asphalt samples with similar performance as Superpave Shear Tester. It is used in combination with Universal Testing Machines (UTM) or Nottingham Asphalt Tester (NAT).

Developed SHEAR1 is capable of measuring the shear properties of asphalt mixtures, and thus the SHEAR1 may be utilized to determine asphalt mixture resistance to permanent deformations, calculate pavement rutting, create mix design and perform pavement material quality checks.

Furthermore, unlike other solutions on the market, it can be used to check the quality of asphalt mixtures from cores taken directly from pavement structures.

Invented at University of California, Berkeley and Czech Technical University in Prague, Product Design by Jakub Stedina



  • Low initial costs
  • Considerably lower operational costs compared to using Hamburg-Wheel Tracking Device or Superpave Shear Tester
  • Only standard laboratory equipment is needed (UTM, NAT, Gyrator)


Can be used for testing laboratory samples or samples taken directly from roads.

Suitable for:
  • Asphalt mixture design
  • Pavement maintenance and quality checks
  • Asphalt mixture component optimization
  • Assessment of asphalt mixture resistance to permanent deformations


  • Shear stress is applied in direction corresponding to the stress created from traffic load in pavement
  • Testing shear properties of asphalt mixtures is therefore closer to real conditions
  • The performance of SHEAR1 has been tested and compared to Superpave Shear Tester. It has shown highly correlated results as published by the inventor


Patent applications

  • Czech Patent granted
  • US Patent granted
  • European Patent granted
  • Australian Patent granted
  • Chinese Patent granted
  • Canadian Patent pending

Successful cases

  • Used in designing a new asphalt mixture ResiSkan by SKANSKA. ResiSkan was designed to ensure resistance to heavy traffic loads and formation of cracks at low temperatures. Link
  • Licence granted in Canada
  • Licence granted in South Africa
  • Distributorship agreement signed with a Chinese distributor with exclusive distribution rights in China

Scientific articles


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