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Timber Design Awards

Hollow Timber Rounds

A new world first innovation in timber structural members has been developed using radiata pine logs

The juvenile core material is removed providing a hollow member of up to 18m in length. The concept of hollow round timbers was conceived by Mark Batchelar of mlb Consulting Engineers. Practical development of the concept has been done in conjunction with TTT Products Ltd Tuakau, described as a MultiPole©. The resulting hollow timber rounds are suitable for use in structural frames and foundation systems. The natural strength and stiffness of the round timber is unaffected. However removing the core material provides significant benefits including:

• An approximate 80% reduction in kiln drying time with consequent major energy savings. A marked reduction in drying checks and member twisting. Constant external diameter provides a high quality structural round timber.

• The ability to provide post-tensioned timber structures using timber rounds with internal tensioning rods. Concept designs have been developed for six storey buildings using this system and modelled to demonstrate suitable low damage performance for Christchurch seismic zone.

• A significant reduction in timber treatment time together with 100% treatment penetration.

• Rapid pile installation in granular sub-soils by means of water jetting through the hollow core, and vibration without the need for pile driving.

• Timbers natural high flexibility to accommodate lateral spread under seismic action

• Reduced foundation costs

• Easy connection of piles to concrete ground floor systems by cement grouting reinforcing tie bars into the pile hollow core.