ISO 1920-12-2015 PDF

Full title and description

Testing of concrete — Part 12: Determination of the carbonation resistance of concrete — Accelerated carbonation method. This International Standard specifies an accelerated laboratory procedure to evaluate and compare the resistance of concrete to carbonation by exposing specimens to a controlled, elevated carbon dioxide atmosphere and measuring carbonation depth.

Abstract

This standard defines a reproducible accelerated carbonation test: after preconditioning and sealing of non-exposed faces, concrete specimens are stored in a chamber with elevated CO2 concentration under controlled temperature and relative humidity for a defined period; carbonation depth is measured (phenolphthalein indicator) and used to compare carbonation resistance between concretes of similar strength and exposure class. The method is intended for comparative evaluation rather than for setting absolute performance requirements.

General information

• Status: Published (International Standard; under routine systematic review by ISO).
• Publication date: May 2015 (first edition, 2015).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 91.100.30 (Concrete and concrete products / Testing of concrete).
• Edition / version: 1st edition (ISO 1920-12:2015).
• Number of pages: 12 (main published document).

Scope

ISO 1920-12:2015 specifies an accelerated laboratory method to determine the carbonation resistance of hardened concrete. The test covers specimen conditioning and sealing, exposure of vertical faces to an elevated CO2 atmosphere in a controlled chamber, periodic removal of slices and measurement of carbonation depth (using phenolphthalein), and reporting of results for comparative assessment. The method gives comparative rather than prescriptive performance results and allows for limited national variations in preconditioning and curing provided they are recorded.

Key topics and requirements

• Specimen preparation and preconditioning (prisms or other shaped specimens; sealing non-exposed faces with paraffin or equivalent before exposure).
• Controlled exposure conditions: typical test uses CO2 concentration (3.0 ± 0.5) % by volume, temperature about (22 ± 2) °C and relative humidity (55 ± 5) % (alternative higher temperature/humidity ranges noted for hot climates).
• Recommended overall exposure/test period (example protocol uses about 70 days) with periodic slicing and measurement of carbonation depth.
• Measurement method: apply phenolphthalein indicator to freshly broken faces and measure carbonation depth perpendicular to exposed surface (precision guidance and recommended number of measurement points).
• Apparatus requirements: a storage/exposure chamber with active control of CO2, temperature and relative humidity; magnifier/gauge for depth measurement; paraffin or equivalent for sealing.
• Results interpretation: method intended for comparative ranking of concretes (same strength class/environment) rather than setting absolute acceptance criteria.

Typical use and users

Used by concrete testing laboratories, research institutions, materials and admixture manufacturers, infrastructure owners, and consulting engineers to compare the carbonation resistance of concrete mixes, evaluate the effect of supplementary cementitious materials or curing regimes, and support durability assessments in design and research contexts. The method is commonly applied where accelerated comparative data are needed for mix development, QA/R and D, or comparative durability studies.

Related standards

ISO 1920-12 is part of the ISO 1920 series (Testing of concrete). Other related parts in the series address chloride resistance, sampling and core testing, nondestructive testing and other test methods for concrete. European standards (for example EN 13295 and national adoptions) define comparable accelerated or natural carbonation test procedures and are commonly referenced in parallel with ISO methods for regional regulatory or product-assessment work.

Keywords

carbonation, carbonation resistance, accelerated carbonation, concrete testing, durability, phenolphthalein, CO2 exposure, storage chamber, ISO 1920 series, accelerated testing.

FAQ

Q: What is this standard?

A: ISO 1920-12:2015 is an International Standard that specifies an accelerated laboratory method for determining and comparing the carbonation resistance of hardened concrete by exposing specimens to a controlled elevated carbon dioxide atmosphere and measuring carbonation depth.

Q: What does it cover?

A: It covers specimen conditioning and sealing, exposure in a CO2-controlled chamber (typical CO2 ~3.0 %), environmental control (temperature and relative humidity), periodic slicing and measurement using phenolphthalein, apparatus and reporting requirements, and guidance on interpretation for comparative purposes.

Q: Who typically uses it?

A: Accredited concrete testing laboratories, university and industry researchers, concrete producers and admixture manufacturers, quality assurance teams and engineers focused on concrete durability and mix design.

Q: Is it current or superseded?

A: ISO 1920-12:2015 is a published international standard (first edition 2015). As of the current ISO listing it remains published and is subject to ISO's regular review cycle for standards (the document is under routine systematic review). Users should check the issuing body for any amendments or newer editions before formal application.

Q: Is it part of a series?

A: Yes — it is Part 12 of the ISO 1920 series (Testing of concrete). Other parts in the series address related test methods (e.g., chloride resistance, core testing, nondestructive tests and properties of fresh concrete).

Q: What are the key keywords?

A: Carbonation, carbonation resistance, accelerated carbonation, concrete testing, phenolphthalein, CO2 chamber, durability, ISO 1920.