Masonry units, segmental pavers and flags-Methods of test: Method 17: Determining initial rate of absorption (suction)

AS/NZS 4456.17:2003: Masonry units, segmental pavers and flags-Methods of test: Method 17: Determining initial rate of absorption (suction)

Understanding the fundamental properties of masonry units is essential for ensuring the long-term performance and durability of any construction project. AS/NZS 4456.17:2003 provides engineers and specifiers with an authoritative method to quantify a critical characteristic: the initial rate of absorption, commonly known as suction. This proven test method is a cornerstone for quality control in the manufacturing of masonry units and for predicting their behaviour in typical construction scenarios.

What is AS/NZS 4456.17:2003?

AS/NZS 4456.17:2003 is an Australian/New Zealand Standard detailing a standardized method for determining the initial rate of absorption (IRA), or suction, of masonry units. Developed by Standards Australia/Standards New Zealand, its primary purpose is to provide a consistent and reliable procedure for measuring how quickly a masonry unit absorbs water when placed in contact with a wet mortar bed. This measure is vital for ensuring proper bond development between units and mortar.

Scope & Purpose

This industry-leading standard governs the testing procedure for determining the initial rate of absorption of masonry units, including segmental pavers and flags. It specifically outlines the apparatus, specimen preparation, procedure, calculations, and recording requirements for this essential material property test. The standard is intended for use by manufacturers and testing laboratories to assess product quality and consistency. It does not cover the long-term water absorption properties or freeze-thaw resistance of masonry units.

Who Must Comply?

• • Primary audience: Materials Engineers, Quality Control Technicians, Building Inspectors, Civil Engineers, Construction Managers, and specifiers involved in masonry construction.
• • Industries affected: Construction, Civil Engineering, Building Materials Manufacturing, Architecture, and Building Surveying.
• • Compliance nature: While not always legally mandatory, compliance is highly recommended for quality assurance, product certification, and to meet contract specifications. It is often a condition for product acceptance by regulatory bodies and specifiers.
• • Enforcement: Compliance is typically checked by quality control departments within manufacturing facilities, independent testing laboratories, and building inspectors during construction.

Key Requirements Overview

The standard requires professionals to:

• • Prepare specimens: Accurately dry masonry units to a constant mass and cool them to room temperature before testing.
• • Conduct controlled immersion: Immerse the bed face of the unit in water for precisely 60 seconds, maintaining a consistent water level.
• • Measure water uptake: Accurately weigh the specimen immediately after immersion to determine the mass increase due to water absorption.
• • Calculate IRA: Apply specific formulas to calculate the initial rate of absorption in kilograms per square metre per minute, differentiating between solid/cored and hollow units.
• • Maintain detailed records: Document all test parameters, specimen details, and calculated results for traceability and reporting.

Related Standards & References

AS/NZS 4456.17:2003 is part of the comprehensive AS/NZS 4456 series, which covers various testing methods for masonry units, segmental pavers, and flags.