Timber structures subject to non-standard fire exposureAdvances & challenges

Hopkin, Schmid & Friquin - WCTE 2016

Thanks to co-authors

Joachim Schmid – ETH Zurich, SwitzerlandKathinka Leikanger – SINTEF, Norway

Danny Hopkin – Trenton Fire, UK

ContextOur ambitions and an awkward past

Some context

Paths to a solution

By convention

Challenge theStatus-quo

History - FR

FR concept applied to the material that led to its inception.

Back to basics – what are we aiming for?• Structural stability in the event of fire• Reducing risk of failure to an acceptable level

The SoA - Steel

Why don’t we do the same for timber?

Define the goal(s)

Define the fire(s)

Heat transfer to elements

‘Test’ structural response

Iterate solutions

Define the goal(s)

Define the fire(s)

Heat transfer to elements

‘Test’ structural response

The fire can’t be detached from the heat transfer

The solutions impact the heat transfer which impact the fire

What have we advanced?Testing & heat transfer simulations

We have done tests...Furnaces:• Konig, et al 1997;• Friquin 2010; &• Kinjo, H, and S Yusa. 2014.

Full or partial scale:• Frangi, A., and Fontana, M. 2005;• Su, J.Z. and Lougheed, G.D., 2014; &• Leikanger Friquin, K. and Hox, K.,

2015.

We have thermal models….• Properties often effective –

do a test – reproduce the outcome;• When the parameters

change (i.e. the fire) the properties are invalid;• ‘Real’ fires:• Konig, J., 2006; &• Hopkin 2011 and 2012.

• But they aren’t very ‘scientific’.

Forward lookChallenges and solutions commensurate with complexity

A universal challenge – what level of performance is adequate?

Heat transfer • Charring rates as a substitute;• Effective properties as a surrogate

for understanding processes;• Defining the fire independently of

the element heat transfer;• All barriers to rational design for

complex structures.

Solutions commensurate with complexity

The tolerable risk is small --- the design confidence must be big

Prescriptive codes cater for the simple, as do the methods that seek to fulfil the requirements

Thanks for your time• Danny.Hopkin@trentonfire.co.uk

• http://uk.linkedin.com/in/dannyjhopkin

• https://twitter.com/DannyHopkin

• http://www.slideshare.net/DannyHopkin

Requested topics: - Recent developments- Behaviour of structural timber elements

in fire- Fire design of insulating bio based

building products (BBBP)- Modification methods, treatments and

durability aspects of fire resistant BBBP- Consideration of additional fire load due

to BBBP- Interaction among Fire Safety Engineers,

Material Scientists & Structural Engineering

- Performance Based Design with combustible products

- Fire Risk and Safety of building with BBBP

- BBBP and their impact on regulations – background for todays’ rules and possible design procedures

Fire Safety Journal special issue

Deadline for papers: 2017-02-28

Life time: 2014/12 – 2018/12

Networking platform for researchers dealing with combustible building products, performance based design and fire safety engineering.

Further information: www.costfp1404.com

COST – European Cooperation in Science and Technology – is one of the longest-running European instruments supporting cooperation among scientists and researchers across Europe.

Working Group 1Contribution of bio-based materials to

the fire development

Working Group 2Structural Elements made of bio-based

materials and detailing

Working Group 3Regulations and standards for fire

safety of bio-based building materialsWorking Group 4

Dissemination

Fire Safety engineers

Material scientists

Structural engineers

COST Action FP1404 Fire Safe Use of Bio-based building products