Sustainable bridges is a term exemplifying the general idea of sustainable development. The concept is a result of the works of a UN commission—the World Commission on Environment and Development—conducted from December 1983 to December 1987 and concluded with the report Our Common Future. At present, several definitions of the basic concept and its specific component…
Sun light or artificially generated electromagnetic waves consists of waves of different lengths. The spectrum of an electromagnetic wave Among these waves microwaves, infrared waves and visible light waves are useful for the distance measurement. In EDM instruments these waves are generated, modulated and then propagated. They are reflected at the point up to which…
For carbon dioxide attack, carbon dioxide dissolves in water to form a weak acid called carbonic acid. It would dissolve the cement matrix. However, the amount of carbon dioxide from the atmosphere is usually not sufficient to cause harm to concrete structures until additional source of carbon dioxide is available (e.g. decaying vegetable matter). Carbonation…
The house is not only a roof, but also a home, the place where it is formed the moral climate and on which lasts the family spirit. UN has classified habitat settlements and identified 10 general functions that every habitat should have. (Recreations and interpretation, Preparing the foods, Eating, Relaxing and Sleeping, Study ,WC, Hygienic…
Reinforced concrete, concrete in which steel is embedded in such a manner that the two materials act together in resisting forces. The reinforcing steel—rods, bars, or mesh—absorbs the tensile, shear, and sometimes the compressive stresses in a concrete structure. Plain concrete does not easily withstand tensile and shear stresses caused by wind, earthquakes, vibrations, and other forces and is…
For simple figures, moment of inertia can be obtained by writing the general expression for an element and then carrying out integration so as to cover the entire area. This procedure is illustrated with the following three cases: (1) Moment of inertia of a rectangle about the centroidal axis (2) Moment of inertia of a…
Simple beam bridges may use wood beams, but modern beam bridges use light and strong materials. Construction of a multi-beam bridge involves the use of a bridge crane, beam clamp for holding, and other tools. Bridge load rating is done to determine the loads that can be safely carried. What is a Bridge? A bridge…
It takes quite a while for carpenter bees to actually cause structural damage to a building but if the extent of their damage does get to the structural level the cost to repair it could be substantial. If you catch them early though, the problem is easily remedied. There are over 500 species of carpenter…
Solid Waste With the ever increasing population and urbanization, the waste management has emerged as a huge challenge in the country. Not only the waste has increased in quantity, but the characteristics of waste have also changed tremendously over a period, with the introduction of so many new gadgets and equipment. It is estimated that…
Our food comes almost entirely from agriculture, animal husbandry and fishing i.e., – 76% from crop lands, 17% from range lands i.e., meat from grazing livestock and 7% – marine and fresh water i.e., fisheries. The FAO (Food & Agricultural Organization of UN) defines sustainable agriculture as the one which conserves land, water and plant…