Using renewable plantation timber as a replacement option for unrenewable hardwood girders in bridges

Figg, Matthew Lorne (2006) Using renewable plantation timber as a replacement option for unrenewable hardwood girders in bridges. [USQ Project]


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This project investigates the possibility of integrating reinforcement with softwood
glulam (glue laminated) timber beams to provide an economic alternative to
hardwood timber girders. The resources of hardwood timbers are dwindling due to a
reduction in tree felling, and hardwood timber plantations are unable to keep up with
demand. Due to this growing shortage, there is an increased need to find a suitable
replacement for deteriorating hardwood timber girders on rural bridges throughout
Queensland. This project analyses a possible alternative. From a design stand point,
the beams should cater for the requirements specified by the Department of Main
An experimental approach has been taken to study the effect of the integration of steel
reinforcing within the laminates of a glulam timber beam. This design will be tested
for strength using a four-point bending arrangement with two hydraulic jacks
providing force on the member.
The results of the test showed the beam catered for the requirements and
specifications outlined by the Department of Main Roads up to 660kN. However,
while the beam supported the load, the tested Modulus of Elasticity (MoE) fell
outside the range of these specifications. It is considered that this could be easily
rectified following minor changes to the design.

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Item Type: USQ Project
Refereed: No
Item Status: Live Archive
Faculty/School / Institute/Centre: Historic - Faculty of Engineering and Surveying - Department of Agricultural, Civil and Environmental Engineering (Up to 30 Jun 2013)
Date Deposited: 11 Oct 2007 01:05
Last Modified: 02 Jul 2013 22:44
Uncontrolled Keywords: softwood; glue laminated (glulam); modulus of elasticity (MoE); hardwood; timber bridges; modules of rupture (MOR)
Fields of Research (2008): 09 Engineering > 0905 Civil Engineering > 090506 Structural Engineering
09 Engineering > 0912 Materials Engineering > 091210 Timber, Pulp and Paper
Fields of Research (2020): 40 ENGINEERING > 4005 Civil engineering > 400510 Structural engineering
40 ENGINEERING > 4016 Materials engineering > 401610 Timber, pulp and paper

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