Overview
ISO 16836:2019 - "Non-destructive testing - Acoustic emission testing - Measurement method for acoustic emission signals in concrete" defines a standardized measurement method for detecting and recording acoustic emission (AE) signals generated by cracking and damage in concrete. The standard supports both laboratory and on-site inspections, prescribing sensor selection, measuring system configuration, signal analysis, calibration and reporting practices to ensure reliable AE-based crack detection and damage evaluation.
Key Topics and Requirements
- Scope: Establishes measurement methods for AE signals in concrete (laboratory and field).
- Detection and Sensors:
- AE sensors convert elastic waves on a concrete surface into electrical signals.
- Choice between resonant and broadband sensors; sensors must be robust to temperature, moisture and vibration.
- Annex A recommends sensor types (e.g., 150 kHz resonant sensors for small specimens).
- Measuring system:
- Typical chain: sensor → pre-amplifier (close to sensor) → main amplifier → band-pass filter → signal processor.
- Amplifier internal noise requirement: inherently low, less than 20 µV (26 dB for 0 dB = 1 µV).
- Recommended band-pass filtering: several kHz to several 100 kHz to reduce noise in concrete applications.
- Calibration and inspection:
- Sensor sensitivity calibration using standard sources (e.g., pencil-lead break as in ASTM E976) and methods in ISO 12713 / ISO 12714; absolute calibration per ISO/TR 13115.
- Routine system inspection; channel variation should be within ±3 dB.
- Signal analysis & parameters:
- AE parameters to be recorded: peak amplitude, AE energy, rise time, duration, arrival times across sensor arrays, and relevant external parameters (load, strain).
- Counting methods: ring-down counts, hit, event; multi-channel event location.
- Data and reporting:
- Adequate data storage (preferably digital) and test report elements (date, test personnel, devices, measurement locations, pre/post-inspection results).
Applications and Users
ISO 16836:2019 is used for:
- Structural health monitoring (SHM) and non-destructive testing of concrete bridges, buildings, tunnels and other civil infrastructure.
- Crack detection and damage evaluation before retrofit or rehabilitation.
- Laboratory research on concrete fracture mechanics and AE characterization.
Primary users include:
- NDT technicians and AE specialists
- Structural and civil engineers
- Infrastructure owners, asset managers and researchers
Related Standards
- ISO 12713 - Primary calibration of AE transducers
- ISO 12714 - Secondary calibration of AE sensors
- ISO 12716 - AE vocabulary
- ISO/TR 13115 - Absolute calibration by reciprocity
- ASTM E976 - Pencil-lead break (standard AE source)
Keywords: ISO 16836:2019, acoustic emission testing, non-destructive testing, AE signals in concrete, AE sensors, crack detection, structural health monitoring.