EN 12697-26:2018/prA1

Overview

EN 12697-26:2018/prA1 is a European standard developed by CEN Technical Committee 227 that defines test methods for characterizing the stiffness of bituminous mixtures used in road construction. This amendment update refines procedures related to specimen dimensions and loading types for stiffness measurement. The standard covers a range of controlled tests, including bending, direct, and indirect tensile tests performed on compacted bituminous materials. The stiffness values obtained help assess pavement structural behavior and rank bituminous mixtures based on relative performance criteria.

Key Topics

• Test Methods for Bituminous Mixture Stiffness
  The standard specifies alternative stiffness measurement methods under sinusoidal or other controlled loadings. These tests include:

  • Bending tests
  • Direct tensile tests
  • Indirect tensile tests

• Specimen Types and Dimensions
  Procedures apply to different specimen shapes such as prismatic and trapezoidal, with minimum dimension requirements adjusted according to the aggregate size in the mixture to ensure accuracy and repeatability in testing.

• Loading Types and Conditions
  The amendment clarifies loading type definitions (for example, DT-CY and DT-PR) used during testing to better standardize the application of forces, enhancing consistency and reliability of stiffness data.

• Application in Pavement Engineering
  The stiffness data assists in:

  • Ranking bituminous mixtures by performance
  • Estimating structural behavior for road design
  • Validating compliance with product standards for bituminous mixtures

• Flexibility for Testing Devices
  No specific testing equipment is mandated, allowing flexibility. However, test conditions must align with the operating range of the device and respect applicable product standards.

Applications

EN 12697-26:2018/prA1 serves as a fundamental reference for:

• Road Construction Material Testing Laboratories
  To perform accurate stiffness testing of bituminous mixtures with standardized specimen preparation and loading protocols.

• Pavement Design and Quality Assessment
  Engineers use stiffness values derived from this standard to model pavement structural performance and optimize mixture selection for durable road surfaces.

• Material Certification and Compliance
  Ensures bituminous mixtures meet stiffness requirements specified in broader product standards, supporting quality control in material production.

• Research and Development
  Provides a validated framework for developing new bituminous formulas and evaluating their mechanical properties under controlled testing scenarios.

Related Standards

• EN 12697 Series – A comprehensive suite covering various test methods and specifications for bituminous mixtures, including compaction, fatigue, and strength testing.
• Product Standards for Bituminous Mixtures – These standards specify the performance requirements and testing criteria that complement stiffness testing under EN 12697-26.
• CEN/TC 227 Documents – Technical committee guidelines for road materials including updates and amendments pertaining to road construction materials testing.

Keywords: EN 12697-26, bituminous mixtures, stiffness test, pavement materials, road construction standards, bending test, tensile test, CEN standard, pavement structural behavior, specimen dimensions, asphalt testing methods.