Rational and sustainable procedure in the design of bridges using pre-stressed concrete beams a theoretical practical method

Currently there is not a direct procedure for the design of this bridge system, still based on trial and error, are no studies that give us both optimum number beams other characteristics such as correct thickness slab or its adequate strength. Keeping in mind concept optimization, which supports idea sustainability environmentally friendly structures, we apply to pre-stressed concrete girder bridges, an integral part road network most countries world. Knowing also produced material by man without it, it would be difficult understand our current world, due own make unique when comes sustainability, however, production requires energy consumption, why optimal superstructure will lead minimum consumption materials obtaining more with nature. It global necessity obtain deliver structures meet conditions sustainability.