Asphalt mixture testing device



Invention description

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

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

Furthermore, SHEAR1 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.
Czech invest

This project was realized with the financial support of the Technology Incubation Programme



  • 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

References & Scientific Publications

Patents Granted in:

  • United States of America
  • European Union
  • United Kingdom
  • Australia
  • Canada
  • China

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