Bird nest construction - lessons for building with earth
The climate changes issue is probable the top priority concern of the governments of the most countries of the world. Rigid and drastic measures have to be taken by all nations in order to reduce the noxious gases emission to the atmosphere. This ambitious goal can be achieved by ruling the energy production, by having a much more sustainable industry and adopting a much more sustainable way of living by all of us. The building industry has also to adapt to these circumstances to make its contribution to achieve the above goal. Focusing on traditional building techniques which require simple technology and use natural and local building materials and, eventually, to adapt them for the present required quality standards may be a step to solve this problem. Half of the world' population, 3 billion people approximately, on six continents, live or work in buildings constructed by earth based building materials. The fact that earth is natural, abundant and local result in an unexpressive amount of energy spending and noxious gases emission when it is used as a building material and, consequently, makes it undoubtedly much more ecological and economic when compared to the others building materials such as reinforced concrete or steel. In this context, the main objective of this research work is to give a contribution on the earth based building material properties and, in particular, for the development of adequate rehabilitation and strengthening techniques, based upon a biomimetic study focused on the andorinha-dos-beirais nest. A structural numerical model of a nest using a finite element computer analysis program was done in order to understand the structural behavior of this kind of natural structures. In order to identify a possible occurrence of a certain agglutination phenomenon during the building process of the nest by the birds, an experimental identification/characterization study of nest's material using samples taken in Vila Real area was carried out. The identification of the elementary chemical and the ...