By Ali Ahrabi
The Canadian Standards Association’s (CSA Group’s) CSA A23.3 standard governs the design of concrete buildings in Canada. It is referenced by both the National Building Code (NBC) and provincial or territorial building codes. NBC 2020 refers to the 2019 edition of CSA A23.3 (CSA A23.3-19) for designing concrete structures.
Annex D of CSA A23.3 is dedicated to the design, installation, and quality assurance requirements for cast-in and post-installed mechanical and adhesive anchors in concrete. This annex became “normative” (i.e. mandatory) in the 2019 edition of CSA A23.3, whereas it was “informative” (nonmandatory) in the 2014 edition. As a result, the requirements outlined in Annex D are now enforceable under NBC 2020 and any provincial or territorial codes that have adopted CSA A23.3-19.
This article will focus on the installation and quality assurance requirements of anchors as detailed in Clause D.10 of Annex D. It will explore the provisions outlined in the 2019 edition of CSA A23.3, discuss the updates introduced in the newly published 2024 edition, and highlight key changes between the two editions.
Clause D.10 in CSA A23.3-19
The 2019 edition of CSA A23.3, Clause D.10, is dedicated to anchor installation and inspection. All anchors must be installed by qualified personnel (Clause D.10.1) following the manufacturer’s printed installation instructions (MPII). For adhesive anchors, this requirement further specifies that only personnel trained in adhesive anchor installation could perform this work (Clause D.10.1).
The required level of inspection for both mechanical and adhesive anchors varies depending on the anchor category specified in the manufacturer’s evaluation report. Adhesive anchors are subject to specific inspection requirements, as outlined in Clauses D.10.2.2 to D.10.2.4, which call for periodic or continuous special inspections. In certain cases, such as adhesive anchors being installed horizontally or upwardly inclined to support sustained tension loads, continuous special inspection is mandatory by a special inspector. D.10.2.4 requires that a special inspector provide a report confirming that continuous inspections have been conducted during the installation of adhesive anchors in these orientations. Such reports verify that all anchor work complied with the approved contract documents and the MPII, ensuring proper installation.
| Type | Continuous special inspection and proof loading | Periodic special inspection |
| a) Adhesive anchors and post-installed reinforcing bars installed in horizontally or upwardly inclined orientations to resist sustained tensile loads |
X | – |
| b) Adhesive anchors and post-installed reinforcing bars not defined in a) | – | X |
| c) Mechanical anchors | – | X |
| Note: Descriptions of typical inspection procedures can be found in the explanatory notes of the Cement Association of Canada’s (CAC) “Concrete Design Handbook.” |
Personnel installing adhesive anchors horizontally or upwardly inclined to support sustained tension loads are required to hold a certification from recognized programs in accordance with the American Concrete Institute (ACI) and Concrete Reinforcing Steel Institute (CRSI) Adhesive Anchor Installer Certification Program or an equivalent certification (Clause D.10.2.3).
The 2019 edition of CSA A23.3 references ACI 355.4 for proof loading requirements where specified by contract documents (Clause D.10.2.2) without providing further clarity for how to accomplish this.
Updates in Clause D.10 of CSA A23.3-24
The 2024 edition to CSA A23.3 introduces several important changes in Clause D.10, broadening its scope and enhancing provisions on quality assurance. The title has been revised to include post-installed reinforcing bars, expanding the range of applications that require inspection.
A significant update is the introduction of D.10.2 Quality Assurance, which provides a structured framework for special inspection requirements. Table D.3 (on page 325 of CSA A23.3-24), a new addition, outlines the minimum levels of special inspection for anchors (adhesive and mechanical) and post-installed reinforcing bars.
The definitions of “special inspection” and its different levels (periodic and continuous) have been added to Clause D.2. Adhesive anchors and post-installed reinforcing bars now have more defined inspection requirements, including clear stipulations for continuous special inspection in cases where they are installed horizontally or upwardly inclined to resist sustained tensile loads. Continuous special inspection and proof loading are also mandated when the manufacturer’s data specifies these conditions.
Another key update includes detailed requirements for proof load testing, as outlined in D.10.2.2.2. This clause specifies the threshold loads to be applied during proof load testing for adhesive anchors and post-installed reinforcing bars. The load, held for at least 10 seconds, must be the lesser of two values: 67 per cent of the published characteristic bond stress capacity (for uncracked concrete, with adjustments for edge distance and concrete strength) or 80 per cent of the minimum specified steel yield strength of the anchor.
The 2024 edition also introduces ASTM E3121/E3121M-17 as the standard for conducting confined proof load tests in situ. A footnote in this section emphasizes that proof load testing is not a substitute for special inspection. These updates clarify the process for performing proof loads, ensuring that anchors are installed properly and consistently.
Additionally, the 2024 edition introduces the defined term “third-party inspector,” emphasizing their role as independent inspectors of anchors. According to the newly added definition of “third-party inspector” in Clause D.2, these inspectors must be hired by the owner or the owner’s representative. They must furnish detailed reports to the licensed design professional and building officials.
Comparison between 2019 and 2024 editions
The 2024 edition of Clause D.10 presents a more comprehensive and clearly defined set of requirements compared to its 2019 counterpart. Expanding the clause to include post-installed reinforcing bars demonstrates a broader recognition of applications requiring quality assurance. Further, introducing specific standards, such as those based on ASTM E3121/E3121M-17, reflects the further clarity required in conducting anchor testing.
While the 2019 edition focused heavily on the proper installation and inspection of adhesive anchors, the 2024 edition provides more details on third-party inspection, continuous special inspection, and the required load level for proof loads.
It is important to note that CSA A23.3-19 is enforceable under the 2020 NBC, setting the regulatory requirements for anchor installation and inspection. However, CSA A23.3-24 is expected to be referenced in the upcoming NBC 2025 and can be considered state-of-the-art in anchor installation and quality assurance requirements.
Conclusion
Whether installing mechanical anchors, adhesive anchors, or post-installed reinforcing bars, the 2024 updates clarify the need for thorough inspections and third-party verification to ensure that installations meet safety and performance standards.
Author
Ali Ahrabi graduated with a bachelor’s degree in civil engineering in 2006 and obtained his master of
science in civil engineering from Concordia University in 2012. He has been a professional engineer in the province of Quebec (Ing.) since 2013 and has experience in various engineering settings. Ahrabi currently serves as the manager of codes and approvals at Hilti Canada. He contributes to developing fastening-related provisions within the National Building Code (NBC) and Canadian Standards Association (CSA) with heavy emphasis on anchors, including contributions to CSA technical committees A23.3, S6, S16, and S304. He can be reached
at Ali.ahrabi@hilti.com.
