Epoxy grouted steel rods
These connections comprise steel rods set into epoxy-filled holes in timber. The rods are placed into oversize holes and the cavity filled with epoxy to enable the epoxy to bond the steel to the timber, thereby enabling the transfer of loads from the timber and into the steel.
These connections allow for the design of aesthetically pleasing high-strength joints.
The technology has been tested in New Zealand and overseas and has been used for around 20 years in New Zealand.
Availability
The materials used for epoxy steel rod connections are commonly available in New Zealand, although specific epoxy resins may need to be sourced from wholesalers or manufacturers.
Restriction on use of the epoxy steel rod system in New Zealand is due to designers’ reluctance to specify the product, which in turn is caused by an unfamiliarity and absence of design criteria in the New Zealand Timber Structures Standard NZS 3603.
Glulam dome roof structure for Sydney 2000 Olympics, featuring epoxied steel rod connections
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Source: Courtesy Timber Design Guide, 2007
Key points
- Steel rods are set into epoxy-filled holes in timber.
- These connections enable aesthetically pleasing high-strength joints.
- Proven technology within New Zealand and overseas.
Recommended links for
Epoxy grouted steel rods
Uses
Significant structures have been constructed using epoxied steel rods, including major structures for the Sydney 2000 Olympic Games.
The technology is suited to joints where a high axial tensile load is to be transferred. Diagrams 1 and 2 show two types of moment connections, diagram 3 illustrates an epoxied apex joint.
Diagram 1: Glue laminated portal frame connection using epoxied rods.
Diagram 2: Multi-storey beam-column connection using epoxied steel rods.
Source: Courtesy Timber Design Guide, 2007.
Diagram 3: Epoxied rod apex joint.
Source: Courtesy D Reid.
