ISO 16837:2019

Non-destructive testing - Acoustic emission testing - Test method for damage qualification of reinforced concrete beams

This document specifies a test for damage qualification of reinforced concrete beams in services as bridges, docks and buildings.

Essais non destructifs — Contrôle par émission acoustique — Méthode d'essai pour la qualification des dommages des faisceaux de béton armé

General Information

• Status: Published
• Publication Date: 23-Jan-2019
• ICS: 19.100 - Non-destructive testing
• ICS: 91.080.40 - Concrete structures
• Technical Committee: ISO/TC 135/SC 9 - Acoustic emission testing
• Drafting Committee: ISO/TC 135/SC 9 - Acoustic emission testing
• Current Stage: 9093 - International Standard confirmed
• Start Date: 03-Dec-2024
• Completion Date: 13-Dec-2025

Overview

ISO 16837:2019 specifies an acoustic emission (AE) test method for damage qualification of reinforced concrete beams used in bridges, docks and buildings. The standard provides a practical framework for applying AE monitoring to assess fatigue, track damage accumulation and support maintenance decisions. It builds on AE principles such as the Kaiser effect and defines measurable ratios to quantify structural deterioration.

Keywords: acoustic emission, AE testing, reinforced concrete beams, damage qualification, Kaiser effect, load ratio, calm ratio, fatigue assessment.

Key Topics

• Measurement system requirements

  • AE sensors must be sensitive to signals generated in concrete, robust against temperature, moisture and vibration, and positioned to cover the target area.
  • Amplifier internal noise should be low (system guidance indicates a low microvolt range) and the frequency range selected considering sensor performance and concrete attenuation (typical AE components are suggested between ~10 kHz and 100 kHz).
  • Systems should capture AE counts/hits with time stamps and, where possible, record external parameters such as load and strain for combined analysis.

• Noise and signal separation

  • Estimate environmental noise before measurement and mitigate sources (wind, traffic, rain, solar effects). Use filtering and frequency selection to separate AE signals from mechanical or electrical noise.

• AE indicators for damage

  • The document emphasizes the Kaiser effect and Felicity ratio as fundamental AE observations.
  • Two new AE parameters are defined: load ratio (ratio of load at AE onset to previous maximum) and calm ratio (ratio of cumulative AE during unloading to total AE in a cycle). These quantify damage accumulation and loss of structural stability.

• Failure mode AE signatures

  • Bending-mode failure: progressive increase in AE counts as tensile cracks nucleate and propagate; crack-mouth opening displacement (CMOD) correlates with Kaiser effect loss.
  • Shear-mode failure: sudden diagonal cracking producing rapid AE count increases with fewer precursors.

Applications

• In-situ qualification of reinforced concrete beams under incremental, cyclic and fatigue loading.
• Quantitative assessment for asset management of bridges, docks and buildings, enabling targeted inspections and maintenance planning.
• Use of load and calm ratios to classify damage levels (minor, intermediate, heavy) after establishing threshold values from site or laboratory data.

Related Standards

• ISO 12716 - AE inspection vocabulary and terms used in AE testing
• ISO/TR 13115 - calibration methods for AE transducers
• Referenced guidance: EN 13554 (general AE principles) and several ASTM/JSNDI documents for sensor mounting, instrumentation and calibration.

Practical notes

• Prior to testing, perform system inspection, attenuation estimation and channel sensitivity checks.
• Report essentials include date, test personnel, devices, sensor locations and pre/post setup system checks and analytical results.

Applying ISO 16837:2019 supports objective, repeatable AE-based evaluation of reinforced concrete beam integrity and helps translate AE activity into actionable maintenance decisions.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 16837
First edition
2019-01
Non-destructive testing — Acoustic
emission testing — Test method for
damage qualification of reinforced
concrete beams
Essais non destructifs — Contrôle par émission acoustique —
Méthode d'essai pour la qualification des dommages des faisceaux de
béton armé
Reference number
©
ISO 2019
© ISO 2019
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ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative reference . 1
3 Terms and definitions . 1
4 Requirement for the measuring system. 1
5 Environmental noises. 2
6 Test procedure . 2
6.1 Basics . 2
6.2 Failure modes of reinforced concrete beams and AE activity . 2
6.3 Load ratio and calm ratio . 3
7 Test report . 4
Bibliography . 5
Foreword
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iv © ISO 2019 – All rights reserved

Introduction
Acoustic emission (AE) techniques are extensively developed in concrete engineering. Concrete
structures have long been referred to as maintenance-free. Recently, however, it is realized that the
concrete structures can deteriorate due to many factors. In particular, heavy traffic loads result in
fatigue of the concrete structures.
In order to assess the fatigue of reinforced concrete beams, one criterion to qualify the damage levels is
proposed on the basis of two ratios associated with the Kaiser effect.
New AE parameters of load ratio and calm ratio are defined for qualification of the damage. It is found
that the damage qualified by the two ratios are in good agreement with actual damage of the beams.
This suggests that the damage of the reinforced concrete structures in service as bridges, docks and
buildings be quantitatively assessed, by simply applying cyclic loading and monitoring AE activity.
INTERNATIONAL STANDARD ISO 16837:2019(E)
Non-destructive testing — Acoustic emission testing
— Test method for damage qualification of reinforced
concrete beams
1 Scope
This document specifies a test for damage qualification of reinforced concrete beams in services as
bridges, docks and buildings.
2 Normative reference
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 12716, Non-destructive testing — Acoustic emission inspection — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12716 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
AE activity
occurrence of AE hits or counts under stressed conditions in concrete
3.2
Kaiser effect
little AE activity (3.1) observed until the maximum load of the previous stage is surpassed when
stresses are applied, removed and then reapplied to a material or a structure
3.3
Felicity ratio
ratio of the load at which emissions start to the previous maximum load when stresses are applied,
removed and then reapplied to a material or a structure
Note 1 to entry: This shows the ratio of the degree of conformity of the Kaiser effect (3.2).
4 Requirement for the measuring system
For detection of AE signals, AE sensors shall be sensitive enough to detect AE signals g
...