Investigations on lesser-used Timber Species for the Construction of light Bridges in Ghana

Swiss Coordinator: Maurice Brunner, Hochschule für Architektur, Bau und Holz (HSB)
Main Foreign partner: Kwasi Frimpong-Mensah, KNUST, Ghana
Cooperation with: Ghana
Disciplines: Material Sciences, Engineering
SNF/DEZA-Research Project 2005-08

Overview

From the forest…	Through the lab…	To the bridge…… in cooperation

Abstract
There is a need for bridges for pedestrians and light traffic over the many small rivers which particularly in the wet season often disrupt movements in both rural and urban areas in many parts of Africa. Timber could be used as a solid, cheap, sustainable and ecological building material. The aim of the project is to develop and promote light bridges (traffic up to 16t) built with lesser-used timber species in Ghana and thus help to solve local transportation problems on the one hand and reduce the danger of the overexploitation of the few widely known and used noble timber species on the other. Locally available materials will be given preference over imported materials like cement. The research activities include:

1. Extension of the data base on selected lesser-used timber species still widely available in the forests with strength tests on members of structural size.
2. Durability tests on the selected lesser-used timber species. Feasibility study on the use of organic rather than chemical preservation liquids to treat non-durable timber species. Such organic preservation fluids will be extracted from the sawmill residue of more resistant wood species such as Bonsamdua (Distemonthus benthamianus) or Neem (Azadinachta indica) or plantation Teak (Tectona grandis).
3. Research on timber bridge systems and connections appropriate to the local conditions with regard to the sawmill production on the one hand and the level of local workmanship and expertise on the other.
4. Research on alternative materials other than imported cement for foundations and abutments, taking into account structural requirements, erosion problems and cost-performance considerations.
   The project organization is centred on the formation of two scientific teams in Switzerland and in Ghana. Students from both countries will be involved in the study of appropriate solutions. The project will last for 3 years. An applied research concept is envisaged. Apart from theoretical and laboratory work, two bridge prototypes will be built: their performance will be monitored for several years afterwards by KNUST. The project will formally end with workshops in Ghana to ensure that the results gain the attention of Government officials, metropolitan and district assemblies, international organisations as well as consulting engineers and contractors.

Contact addresses in Switzerland:

Project Coordinator:
Maurice Brunner,
Dr. sc. Techn. ETH
Prof. for Structure
Division of Wood Engineering
Berner Fachhochschule
Berne University of Applied Sciences
School of Architecture, Civil and Wood Engineering HSB
Burgdorf, Biel
Solothurnstrasse 102
P.O. Box
CH-2500 Biel-Bienne 6
Phone: +41 (0)32 344 03 78
Fax: +41 (0)32 344 03 90
E-mail: Maurice.Brunner@bfh.ch
Internet: http://www.hsb.bfh.ch

2nd Coordinator:
Ernst Zürcher
Dr. sc. Nat. ETH
Prof. for Wood Science
Division of Wood Engineering
Berner Fachhochschule
Berne University of Applied Sciences
School of Architecture, Civil and Wood Engineering HSB
Burgdorf, Biel
Solothurnstrasse 102
P.O. Box
CH-2500 Biel-Bienne 6
Phone: +41 (0)32 344 03 67
Fax: +41 (0)32 344 03 90
E-mail: Ernst.Zuercher@bfh.ch
Internet: http://www.hsb.bfh.ch

Project Administration:
Kurt Wüthrich
Dipl. Holz.Ing. HTL
Coordinator for Cooperation with Developing Countries
Berner Fachhochschule
Berne University of Applied Sciences
School of Architecture, Civil and Wood Engineering HSB
Burgdorf, Biel
Solothurnstrasse 102
P.O. Box
CH-2500 Biel-Bienne 6
Phone: +41 (0)32 344 03 91
Fax: +41 (0)32 344 03 90
E-mail: Kurt.Wuethrich@bfh.ch
Internet: http://www.hsb.bfh.ch