Bridges

Bonded Anchors are a type of connection which comprises a metal component, either a length of reinforcing bar, a threaded bar or a purpose-made anchor in combination with an adhesive. This type of anchor is increasingly being used to connect road-structure components. However, although Bonded Anchors have been available for several decades, the use of this technology in road-structures and the associated risks are not well understood by designers. Furthermore, their installation is not reliably and consistently implemented by contractors.

Evidence suggests that Bonded Anchors are used for convenience rather than because they are the most appropriate solution and that the suitability of Bonded Anchors for use in road-structures, particularly those that require a design life in excess of 50 years, is not properly considered.

Correct design, specification and workmanship are essential to a successful and durable outcome. Concerns exist regarding the approach taken by designers when considering the suitability of bonded anchors for particular connections and regarding workmanship during installation.

This paper discusses the approach taken by VicRoads to the design, specification, installation and testing of Bonded Anchors as described in Bridge Technical Note BTN2012/002 Bonded anchors together with VicRoads Standard Specification Section 680 Bonded anchors. The basis of the documented provisions for design of anchors subject to sustained tension is discussed together with design-life considerations, permitted uses and restrictions on use.