17-04-2013, 03:12 PM
NANO TECHNOLOGY IN CIVIL ENGINEERING
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ABSTRACT
Nanotechnology is an enabling technology that allows us to develop materials with improved or totally new properties. Nano technology is used in concrete, glass, steel ,coatings. The concrete is prepared by nano particles mainly are nano silica, titanium dioxide, carbon nano tube, nano technology used in glass preparation and water repellent process. Nano technology used in steel fatigue, It is a significant issue that can lead to the structural failure of steel subject to cyclic loading .stress risers are responsible for initiating cracks from which fatigue failure results and the addition of copper nano particles reduces the surface unevenness of steel which then limits to the number of stress risers hence fatigue cracking. Nanotechnology used in cables, joints and welds. The refinement of the phase of steel to a nano size has produced stronger cables high strength steel cables being used in car tyres and used in bridge construction and pre casting concrete. High – rise structure require high strength joints this in turn leads to need for high strength bolts which are generally gone through quenching and tempering marten site. Heat effected zones adjacent to wells can be brittle and fail without warning when subjected to sudden dynamic load when addition of nano particles of magnesium and calcium makes (haze) green finer in plates steel. That increase weld toughness. Nano technology is being applied to paints and insulating properties, produced by the addition of nano-size cells, pores and particles, giving very limited path for turmal conduction are currently available.Nano technology used in fire protection . This is achieved by a clear in tumescent layer sandwiched between glass panels (an internal layer) formed by fumed silica(sio2) nano particle which turn’s into grid and opaque fire shield when heated.