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SUSTAINABLE STRUCTURES WITH COMMENTS ON FIB MODEL

CODE 2010 (NMC 2010)

Horst FALKNER (1), Christian KORKOWSKI (2)

(1) Technical university Brunswick/Consulting office Dr. Falkner GmbH, Stuttgart, Germany

(2) Consulting office Dr. Falkner GmbH, Stuttgart, Germany

Abstract Sustainability is a governing target for all industrial development round the world.

Pollution in the air, the soil and the water, as well the shrinking natural resources have become an alarming threat, not just for our generation, but especially for the generation to follow.

In 1987 the phrase “sustainable development” was first introduced in the Brundtland Report. It was defined as “development which meets the needs of the present without compromising the ability of future generations to meet their own needs”. In the building industry many ways and means exists to contribute to achieving this aim.

The paper deals with structural aspects considering historic structures, management, maintenance, recycling material and sustainability criteria as demand in a first draft in the fib model code 2010. There will be also given information about certification systems for sustainability and the share of European building industry to the gross national production.

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Finally some information is given to the famous mathematician Carl Friedrich Gauss (1777 - 1855), the most famous student of the technical university of Brunswick, Germany.

1. INTRODUCTION AND BACKGROUND

Throughout history man kind practiced predatory exploitation of natural resources, resulting in an increasing unsettlement of our planets ecological balance. For instance 2000 years ago the Romans deforested great parts of Istria and Dalmatia (Croatia) in an effort to enlarge their fleet. Up to this day the local ecosystem was not able to recover from this massive impact.

However, today the impact of man kind on nature is more severe than ever before. The explosion of the industrialization has lead to mass production, mass consumption and mass disposal, resulting in environmental pollution and exploitation of natural resources to a degree exceeding allowable limits. Polluted rivers, soils and air, as well the shrinking natural resources have become an alarming threat, not just to our generation, but especially for the generations to follow.

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These facts and the immanent scarcity of natural resources have lead to a paradigm shift in

the last decades of the 20th Century. In 1987 the phrase “sustainable development” was first introduced in the Brundtland Report. It was defined as “development which meets the needs of the present without compromising the ability of future generations to meet their own needs” [1]. Especially in the building industry many ways and means exist to contribute to achieving this aim [1, 2].

2. HISTORIC STRUCTURES

Many of the structures built today will not only outlive our generation but might as well outlive many future generations. The Egyptian Pyramids and the Chinese Wall are just two good examples of how much responsibility for future generations, regarding aspects such as aesthetics and functionality of structures lies within the hands of designers and planers of new buildings.

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3. MANAGEMENT - MAINTENANCE

The functionality of a building can only be ensured for the future, if maintenance is performed on a regular basis [3]. Factors greatly influencing the extent and costs of maintenance work are the initial quality of the structure and the inspection intervals. Even though the initial costs of high quality products might be greater, fewer inspections and less maintenance work often make such products more economic on a long-term view. Examples for such high quality products made in Germany are the Transrapid in Shanghai and several components of the Burdsch Chalifa in Dubai [4, 5].

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4. SUSTAINABILITY CRITERIA

In order to construct a new building according to modern sustainability criteria architects and engineers need to consider a possible change of function in future as well as the dismantlement and recycling of the structure in the planning phase. The combination of these demands and the required regular inspections and maintenance works make a life-cycle design for new structures just as inevitable as the design for ULS and SLS [1, 2, 6].

The building industry produces approximately 30 % of the CO²-Emission and 40% of the

energy consumption. Therefore the building industry must have great interest in the promotion of renewable energies like wind, solar, hydropower and others. Several new projects such as huge offshore wind parks are already planed for the near future, but the prediction of the future energy-mix, displayed in the graph above, clearly shows the increasing importance of renewable energy sources, therefore research in this field needs due attention, to achieve more milestones, like the first solar driven aeroplane “Solar Impulse” [7, 8].

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5. FIB MODEL CODE 2010 - SUSTAINABILITY

More than 20 years after the Brundtland Report the fib Model Code 2010 is the first structural code to consider the sustainability of structures. However, at present only few general criteria and methods are available for verifying sustainability, therefore the idea of sustainability criteria is still in a state of development and will need due attention in future.

In general one of the main aims for the development of the new fib Model Code 2010 (NMC 2010) was to create a future orientated document taking due account of social development. This has led to a code that is basically orientated to life cycle thinking and sets new standards for design criteria. The intention is that apart from conventional design, dimensioning and construction, the conservation and even dismantlement of structures is to be considered in the process of planning. More over design criteria such as durability, robustness and especially sustainability are introduced in the NMC. In future, consideration of these criteria in the process of planning will gain in importance [1, 2].

6. CERTIFICATION SYSTEMS FOR SUSTAINABILITY

New methods, tools and rating systems to assure the sustainability criteria for future buildings are being developed and have partially already been introduced by institutes like the DNGB in Germany, the HQE in France and the U:S: Green Building Council around the World.

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The leading and most widely used assessment method for buildings is the BREEAM (BRE

Environmental Assessment Method) developed by the British Research Establishment (BRE) in the 1990’s. It is a tool to describe a building’s environmental performance and help clients, developers and designers to minimize the environmental impact, reduce costs and improve working and living environments.

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Another program established by the Abu Dhabi Urban Planning Council (UPC) in 2002,

developed especially for the harsh climatic conditions in the United Arab Emirates, is the ESTIDAMA. This Program, which name means sustainability in Arabic language, is meant to

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promote the vision formulated in the Abu Dhabi 2030 plan of sustainable Cities in the dry dessert climate. The resource intensive environmental impact of creating electricity and the desalination of water, combined with predicted population growth, is a challenge for the region and underlines the necessity of the program. One of the major projects in the ESTIDAMA is the planned “plus energy City” Masdar City near Abu Dhabi.

7. THE EUROPEAN BUILDING INDUSTRY

The importance of the building industry in Europe is clearly documented by its 10 % share of the gross national production. Considering the year 2008 this resulted in a total amount of 1000 billion € invested in the building sector [7].

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8. GAUSS, STATISTICS AND THE TECHNICAL UNIVERSITY OF BRUNSWICK

The famous mathematician Carl Friedrich Gauss (1777-1855) is familiar to all engineers around the world. However, only few people know about his personal and educational background. The Technical University of Brunswick is proud to state that Carl Friedrich Gauss is the most famous graduate to have studied at the University. Gauss was a student at the University of Brunswick from 1795 to 1799 [9]. A great part of today’s technical, statistical, economical and ecological determinations and research activities are based on the statistical Gaussian distribution. Due to his contribution to the progress of science his portrait was printed on the 10 DM note. The Deutsche Mark has gone, substituted by the Euro, but Gauss will stay for ever!

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Besides this fact, the Technical University of Brunswick, established by the Duke of Brunswick in the year 1745 more than 260 years ago, is proud to be the oldest Technical University in Germany.

The author is also very pleased to inform that Professor Jianzhuang Xiao has joined the Institute for Structural Engineering at the Technical University of Brunswick from 2004 to 2006. He spent his time in Brunswick with fruitful research work in the field of fatigue and modelling of material in reinforced concrete.

The University of Tongji and the University of Brunswick have been working together in many fields for 25 years. During this time a permanent exchange of outstanding scientists was organized, resulting in a substantial and sustainable enhancement of the quality of both Universities – Tongji and Brunswick.

REFERENCES

[1] fib Bulletin 55, “Model Code 2010 – first completed draft, Volume 1”, (April 2010). [2] fib Bulletin 56, “Model Code 2010 – first completed draft, Volume 2”, (May 2010). [3] Walraven, J., “Toward a New Model Code for Concrete Structures“, African Concrete Code

symposium, (2005) 44-58. [4] Falkner, H., “Quality and Robustness of Structures”, Presentation of the VDB Verband Deutscher

Betoningenieure e.V., (Hamburg, Germany,2010). [5] Falkner, H.; Gerritzen, D.; Korkowski, C., “New Column Types with High-Strength

Reinforcement Steel SAS 670/800 – Theory and Practical Application Considering the Examples Opernturm Frankfurt and Uni-Klinikum Ulm“, High Rise Towers and Tall Buildings 2010, conference proceedings, (Munich, Germany) 48-55.

[6] Comité Euro-International du Béton, “CEB-FIP Model Code 1990, Design Code”, Thomas Telford Services Ltd (London, 1993)

[7] Nußbaumer, M., “The Sustainable City from the View Point of the Building Industry“, VDI-Forum (Stuttgart, Germany, June 2010)

[8] Hegger, M., “Sustainable Structures”, Verification Engineers Conference (Baden-Baden, Germany, June 2010)

[9] Mania, H., “Gauss, a Biography”, ISBN 3-499-62531-8 (Reinbek near Hamburg, Germany, 2009)