Pioneering research on the durability of low embodied carbon sustainable elements and systems
Tuesday 17 June 2025, 1:36AM
By Dr. Gary Raftery
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At the University of Auckland's Newmarket research laboratories, novel investigations are being undertaken to advance core durability knowledge in relation to the development and applications of low embodied carbon laminated timber systems for civil infrastructure and structural applications.
The scientific studies are assessing the durability performance of elements which can help New Zealand to achieve its net zero carbon goals more efficiently and establish increased confidence in the next generation of laminated timber elements which can adequality satisfy the requirements of a complete design service life for full external exposure in New Zealand's diverse climate.
Net zero carbon goals are about achieving a balance where greenhouse gas emissions from human activities are reduced and offset, leading to a net-zero impact on the climate.
Dr. Gary Raftery, Co-Director of the CIRCUIT research centre at the university is directing and supervising the research programmes with his team.
Mr. Weixi Wang, a Phd student in the Department of Civil and Environment Engineering, is conducting extensive studies which are focused on assessing the service lifespan of cross bonded assemblies of laminated timber systems that can enable the domestic industry transition with greater ease to a circular economy.
It is widely known that the built environment is one of the most significant contributors to global warming and the adverse effects of climate change.
With the dominant use of chromated copper arsenic impregnated wood for exterior applications, significant technical challenges are presented for the possibility of reuse, repurpose and remanufacture, which are the most favoured approaches in a circular economy.
The current research examines the performance of alternative practices which can have more favourable end-of-life options.
Innovative assessment procedures such as the quantification of fracture energy by the single end notched beam fracture test, secondary investigative techniques such as scanning electron microscopy analyses and fourier transform infrared spectroscopy to examine possible chemical incompatibilities or irregularities during ageing of the assemblies, are being conducted.
Laboratory produced assembles are being subjected to accelerated ageing regimes in advanced environmental chambers at the university which can replicate real world environments.
Such artificial ageing is complimented by natural exposed specimens where environmental variables such as ultraviolet radiation, solar energy, moisture content variation, daily rainfall, temperature and relative humidity are recorded.
Initial calibrations between the two approaches have been conducted.
The research will address key questions to further advance the increased development of sustainable and low carbon civil infrastructure such as the construction of full-scale vehicle bridges.
Waka Kotahi New Zealand Transport Agency (NZTA) and chief engineer Sulo Shanmuganathan places strong focus on such sustainable and resilient infrastructure and have played a fundamental role for the hosting of the upcoming International Conference on Timber Bridges (ICTB 2025) in the southern hemisphere for the first time.
The conference is scheduled from 29 June - 2 July, 2025 in Rotorua.