New Guide for Standard Practice for Internal Swelling Reaction(s) Examination using the Damage Rating Index
1. Scope
1.1 This practice outlines procedures for the examination of samples of deteriorated hardened concrete. The samples examined may be taken from concrete constructions, they may be concrete products or portions thereof, or they may be concrete specimens that have been exposed in natural environments, or to simulated service conditions, or subjected to laboratory tests. The phrase “concrete constructions” is intended to include all sorts of objects, units, or structures that have been built of hydraulic cement concrete.
1.2 The procedures outlined herein are applicable to the examination of samples of hardened concrete affected by alkali-aggregate reaction, delayed ettringite formation, and/or freezing and thawing. Other types of hardened concrete deterioration may be examined.
1.3 This practice estimates the level of deterioration given a type of deterioration and does not replace diagnostic testing.
1.4 The purposes of and procedures for internal swelling reaction(s) examination of hardened concrete are given in the following sections:
Section
Qualifications of Operators and use of Technicians/Technologists 6
Purpose of examination 7
Apparatus 8
Samples 9
Specimen Preparation 10
Procedures 11
Calculation 12
Report 13
1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
Internal swelling reactions are among the most damaging deterioration mechanisms affecting concrete infrastructure globally. While conventional microscopy techniques—such as optical and scanning electron microscopy—are widely used to identify the causes of damage, they are not effective in quantifying its extent. This limitation hinders the ability to assess severity, compare cases, and prioritize interventions.
The Damage Rating Index (DRI) addresses this gap by providing a standardized, reproducible method to evaluate the degree of damage in concrete affected by swelling reactions. By translating visual observations into quantifiable metrics, the DRI enables more consistent assessments across projects and regions.
This standard will be used by petrographers, civil engineers, materials scientists, infrastructure managers, and regulatory agencies to guide maintenance strategies, support rehabilitation planning, and improve long-term durability assessments. It will also facilitate clearer communication among stakeholders and contribute to more data-driven decision-making in concrete infrastructure management.
