International Concrete Abstracts Portal

This CD-ROM contains 18 papers that were presented at sessions sponsored jointly by Committee 355 & 503 at the ACI 2010 Spring Convention in Chicago, IL. The objective of the papers is to provide a reference document and give a better understanding of the performance, capability, and reliability of adhesive anchors installed in concrete. The papers present the design, installation, qualification, and inspection requirements. Other papers discuss the characteristics of sustained load behavior and other specific anchor installation and qualification considerations. Note: The individual papers are also available. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP-283CD

In the last 10 years there have been tremendous developments made in the strength of the adhesives and the fields of applications of adhesive anchor systems. Hence these systems are used for structural attachments in a wide variety of applications in concrete construction. Suitable products, careful selection and design, and proper installation are vital for the overall performance of a structural connection. While suitable products prequalified under provisions such as AC308 and ACI 355.4-10, and produced under strict quality control are or will be on the market – demonstrated by an Evaluation Service Report - and rational design models have been developed to ensure a reliable use of adhesive anchor systems in daily construction practice, the knowledge of the designers and installers in fastening technology is often not adequate. The knowledge of the designers should be updated regularly. Adhesive anchors should be installed by properly trained installers. However, the training of the installers needs to be improved significantly. The proper training should be demonstrated by a certificate that is issued by an independent agency after passing a corresponding test. The new ACI Anchor Installer Certification program that is currently under progress will fulfill this requirement.

International efforts to harmonize the testing, qualification and design of post-installed anchors have resulted in closely aligned standards / guidelines in Europe and the U.S. The implementation of ETAG 001, Part 5 (EOTA 1997) in the E.U. and AC308 (ICC-ES 2006) in the U.S. represents a major new step in the harmonization efforts and has resulted in nearly parallel approaches in the two regions with regards to the qualification and design of adhesive anchors. Nevertheless, while the standards alignment permits portability of test data from one system to the other, significant differences remain between the two systems. In addition, efforts to adopt AC308 into the building code for structural concrete in the U.S. (ACI Committee 355 2008) have resulted in further dissimilarities. This paper focuses on the similarities and differences between the European and American qualification systems for adhesive anchor products. An insight into the issuance of Evaluation Reports and Technical Approvals is provided. Information regarding manufacturing and quality control requirements imposed as a part of the product qualification is included. A brief review of the design procedures adopted in ETAG 001 and in AC308 is provided. The current status of the ACI 355.X standard which is currently under development is also discussed, and regional differences in job-side quality control and installation inspection are discussed.

The design provisions for anchoring to concrete in ACI 318-08 Appendix D (ACI Committee 318 2008) specifically exclude adhesive anchors while noting that "Adhesive anchors are widely used and can perform adequately. At this time, however, such anchors are outside the scope of this appendix." Development of suitable design provisions for adhesive anchors requires that 1. The provisions be structured to fit the design paradigm currently being used in ACI 318-08 Appendix D (ACI Committee 318 2008); and 2. A suitable companion standard to ACI 355.2 (ACI Committee 355 2007) be developed for the testing and assessment of adhesive anchor systems to be used in conjunction with the new provisions. The design model is substantially based on the work of Eligehausen, Cook, and Appl (Eligehausen et al. 2006). It incorporates a new failure mode (bond) that must be included along with the other tension failure modes in establishing the controlling strength. The bond failure model, which incorporates a unique approach to group and edge effects reflective of numerous experimental and numerical investigations, is nevertheless predicated on a simple uniform bond stress approach. Of equal importance is the implementation of a host of new suitability tests for adhesive anchor systems as well as a particular emphasis on long-term strength and job-site quality control. In this context, the provisions for inclusion of adhesive anchors in ACI 318-11 (ACI Committee 318 2011) are reviewed together with the approach taken to testing and qualification under the new ACI standard ACI 355.4-11 (ACI Committee 355 2011).

Inspections in building construction have vital importance and are needed to verify that work considered critical to life, public safety and property protection is being or has been performed according to the approved plans and specifications. While the building official is obligated to inspect the construction progression at certain stages, some building construction activities demand closer scrutiny. This additional level of surveillance is known as special inspection. Because proper installation of adhesive anchors requires inspection procedures beyond those in the building codes, special inspection is needed. Clear, detailed specifications are essential to assure that the anchor is installed as intended, and verification in the form of inspection is needed to further assure installation-related tasks are performed properly.