Hybrid Beams for Sustainable Replacement of Hardwood Timber in the Construction Industry

The need to develop alternatives to hardwood bridge girders has caused a range of questions to be raised that have notbeen evident while conventional hardwood girders have been used to construct and rehabilitate timber bridges. The potential to obtain engineered products brings with it questions about the appropriate design approach that should be used, particularly with the introduction of the new SM1600 bridge load model. 

Alternatives can be broadly summarised as:

1. Use the characteristic design values from AS1720.1 as target characteristic values;

2. Use the bridge loading code, and a rational design methodology;

3. Specify that new alternatives must match the behaviour of old growth hardwood girders.

Alternatives other than (1) to (3) may also exist. Currently products are being developed using each of the above approaches.