CALCESTRUZZO: UNA TECNOLOGIA SEMPRE PIÙ PERFORMANTE

The concrete appeared to aspire to eternity conditions in relation to the traditional technological system and the applications. Nevertheless, since 1800 it has opened up to innovation for reaching better performance. The ecological concretes are obtained with the addition of fly ash and silica fume, industrial waste consisting of micrometer-size particles such as those of the cement. In the second half of the twentieth century, these mineral additives have given the concrete a significant flowability, to the benefit of the casting workability. In the end of the century, mineral additives have made self-compacting concrete (SCC). It means that concrete is able to fill a formwork without vibration. Also synthetic micrometersized fibers give the concrete an uniformly distributed reinforcement. The polymeric fibers represent the new fiber-generation and they give fiber reinforced concrete (FRC) a prevention from cracking, but also a better durability in relation to an enhancement of the mechanical properties, toughness and ductility. Finally, there is a smaller scale with unparalleled performance: the nanometer-size, which is based on titanium dioxide nanoparticles and carbon nanotubes. The first interaction allows concrete to access smart materials, giving the concrete selfcleaning and anti-pollution effect. On second thoughts, the concretes reinforced by carbon nanotubes (CNTSCC) are stronger and more tenacious. They are usable in considerable structural effort applications. Many other innovations are on the horizon according to a more and more performing technology.