wood protection by design

OBJECTIVES AND STRUCTURE OF THE PROJECT
The research within the WoodWisdomNet project DuraTB aims to significantly
improve the general standing and applicability of wood as structural material in bridges.
Therefore various technical and scientific objectives were followed in five different
work packages and numerous tasks as shown in Table 1 and Fig. 3.
Table 1. Project topics divided into work packages and tasks.
Work package Task Description
1. Coordination 1.1 Project management
2. Performance 2.1 Collection of field data from existing instrumented bridges
based service life 2.2 Development of climate exposure model for bridge structures
design of timber
bridges
2.3 Tests of climate exposure (moisture content, temperature) in
structural details
2.4 Development of suitable dose-response model for fungal
decay
3. Hygro-thermal
effects in wooden
members
4. Design
concepts for
durable timber
bridges
2.5 Methodology for service life design of bridges
3.1 Numerical models relating rain, spray, RH, T, to distribute
material climate effects in members
3.2 Moisture distribution, moisture induced stress and risk of
cracking in members in connections
4.1 Wooden bridge decks
4.2 Design concepts for short to medium span bridges
4.3 Design concepts for medium to long span bridges
4.4 Splicing of large glulam members
4.5 Fatigue of axial-carrying connectors in wooden members
4.6 Performance evaluation of design concepts (structural
performance, lifetime, LCC, LCA)
4.7 Maintenance practices and repair techniques for extending
service life of timber bridges
5. Dissemination 5.1 Produce a book or report on design of durable timber bridges
5.2 Arrange open workshops
5.3 Prepare proposals to CEN TC 250 SC 5 to the new generation
of EN 1995-2 Timber bridges
5.4 Publication in scientific papers, journals and conferences
Within WP 2 data from weather and material climate monitoring (examples shown in
Fig. 1) on field trials and real structures in service are collected and used for modelling
decay and consequently performance of bridge components and details. Finally, an
engineering design concept will be developed on the basis of previous guidelines for
timber used in arbitrary above ground conditions (Isaksson et al. 2014). The doseresponse
models are going to be used to evaluate durability and expected service life of
the bridge design concepts proposed in WP 4.
WP 3 focusses on the hygro-thermal behaviour of wooden members. Numerical
modelling (FEM) and simulation are applied and adapted to large-size glulam
structures. Therefore data from long-term recording of bridge structures in different
Nordic countries were used to verify and further develop existing models. Design
concepts for durable bridges with a span range of 10 to 150 m will be developed in
WP 4. Therefore network arch bridges with hangers crossing each other at least twice
located in one plane are considered as a promising starting point. The so-called ‘spoked
wheel’ configuration may further improve this concept with pairs instead of single