A new strategy to reduce the environmental impact of FRC

Concrete cylinders are subjected to uniaxial compression tests in order to define the whole mechanical response of different mixtures, including the strength and the post-peak ductility. With respect to traditional concretes, the deleterious effects produced by the reduction of cement content (and thus of dioxide carbon emission) can be mitigated by adding mineral admixtures and/or fibers. For instance, fly ashes and silica fumes can increase the compressive strength, even in the presence of a high water/cement ratio. Similarly, low amounts of steel fibers (less than 1% in volume) can drastically enhance the post-peak toughness. Starting from these experimental observations, a new eco-mechanical index is here introduced with the aim of defining an effective strategy to reduce the environmental impact of concrete, without any mechanical detriment. The theoretical and the experimental analyses here developed seem to confirm that the idea of tailoring a new generation of fiber-reinforced concrete, capable of maintaining high mechanical properties with a reduced amount of cement, is not a chimera.