EN ISO 16383-1:2025 PDF

Overview

EN ISO 16383-1:2025 - "Geotechnical investigation and testing - Laboratory testing of rock - Part 1: Determination of water content" specifies the laboratory oven‑drying method for determining the water content of rock specimens. The standard defines the practical procedure: measure mass loss when a rock specimen is dried to a constant mass in a controlled drying oven and report water content as the ratio of free water mass to the remaining dry mass. This method is the definitive laboratory procedure used in geotechnical investigations.

Key topics and technical requirements

• Scope: Laboratory determination of rock water content by oven‑drying for geotechnical investigation.
• Definition of water content (w): Ratio of mass of free water to dry mass of test specimen.
• Constant mass: Less than 0.1% further change in mass over three consecutive measurements taken at least 1 hour apart.
• Equipment requirements:
  • Drying oven: forced‑draft type providing uniform temperature.
  • Thermometers/thermocouples: oven temperature device ≤1 °C error (0.1 °C resolution); ambient thermometer ≤0.5 °C error (0.1 °C resolution).
  • Balance: maximum permissible error 0.01 g or 0.1% of the weighed mass, whichever is greatest.
  • Hygrometer: max permissible error 5%, resolution 1%.
  • Specimen containers: glass, porcelain, or corrosion‑resistant metal that do not change mass with repeated drying cycles; lids recommended to prevent moisture exchange.
  • Desiccator (optional): with dry, self‑indicating desiccant (e.g., silica gel) to avoid moisture uptake prior to weighing.
• Procedure elements: specimen size and preparation, drying to constant mass, weighing protocol (insulation if weighed hot), calculation of mass loss and water content.
• Quality and calibration: Annex A covers calibration, maintenance and checks for equipment to ensure accurate results.

Practical applications

• Provides an authoritative method for determining rock water content used as input to:
  • Foundation and geotechnical design (EN 1997‑2 compliant testing)
  • Rock mass and slope stability assessments
  • Tunnel, underground works and excavation planning
  • Laboratory characterization in mining and civil engineering projects
  • Quality control of rock samples prior to other laboratory tests
• Useful for producing reliable, comparable water content data used in classification, modelling and safety assessments.

Who should use this standard

• Geotechnical engineers and consultants
• Rock mechanics and laboratory technicians
• Construction and tunnelling project teams
• Accreditation bodies and testing laboratories
• Standards committees and educators in geotechnical engineering

Related standards

• ISO 16383 series (other parts covering laboratory testing of rock)
• ISO 14689 - Identification, description and classification of rock
• EN 1997‑2 - Geotechnical investigation and testing (reference for geotechnical practice)

Keywords: EN ISO 16383-1:2025, water content of rock, rock water content determination, geotechnical investigation, laboratory testing of rock, oven-drying method, drying oven, constant mass, specimen preparation.