EN 13398:2017

Overview

EN 13398:2017 is a European Standard developed by CEN that defines a precise method for determining the elastic recovery of bitumen and bituminous binders. This standard is particularly designed for modified bitumen, especially those enhanced with thermoplastic elastomers, but also applicable to other bituminous binders exhibiting minimal recovery. The test is performed using a ductilometer at controlled temperatures, typically 25°C or 10°C, but alternative temperatures can be utilized depending on binder characteristics. The method involves stretching a bitumen specimen to evaluate its ability to recover elastically after being deformed.

Key Topics

• Elastic Recovery Measurement: The standard specifies how to measure the elastic recovery (RE) of molded bitumen specimens stretched to 200 mm elongation in a ductilometer and then cut to monitor recovery after 30 minutes.
• Test Conditions: Temperature control is critical, with ±0.5°C accuracy in a water bath to maintain the bitumen at the required testing temperature.
• Specimen Preparation: Preparation of samples follows strict guidelines, including moulding procedures, temperature conditioning, and use of release agents to ensure consistent test conditions.
• Apparatus Specifications: Details about the mould dimensions, traction device speed control (50 mm/min ±2.5), and temperature-controlled water bath are specified to ensure repeatability.
• Calculation Method: Elastic recovery is calculated as a percentage of the shortening of half-threads relative to the original elongation, with clear guidance on handling premature breaks.
• Precision and Repeatability: The standard includes repeatability and reproducibility data based on interlaboratory round-robin tests, confirming the method’s reliability within 4% and 7% tolerances respectively.

Applications

EN 13398:2017 is essential for:

• Quality Control of Modified Bitumen: Ensures bituminous binders modified for enhanced elasticity meet performance criteria, crucial for road construction and waterproofing materials.
• Performance Evaluation: Helps assess materials used in flexible pavements where elastic recovery affects durability and crack resistance.
• Material Development: Facilitates research and development of new modified bitumen formulations by providing a standardized metric for elasticity.
• Compliance and Certification: Supports manufacturers and testing laboratories in complying with European regulations and ensures consistent characterization across different labs and production batches.

Related Standards

• EN 58 – Sampling procedures for bituminous binders, ensuring representative sample collection for testing elastic recovery.
• EN 1427 – Determination of softening point by ring and ball method, critical for conditioning tests in EN 13398.
• EN 12594 – Guides the preparation of bitumen test samples, ensuring uniform specimen quality.
• EN 1431 – Measures residual binder and oil content in bitumen emulsions, complementary for quality assessments.
• EN 12607-1 and EN 12607-2 – Methods for determining heat and air hardening resistance of bituminous binders, often used alongside elastic recovery testing to fully characterize binder performance.

Keywords: EN 13398:2017, bitumen elastic recovery, modified bituminous binders, ductilometer test, thermoplastic elastomers, bitumen testing standards, elastic recovery method, flexible pavement materials, bitumen quality control, CEN bitumen standards, bituminous binder properties.