Ecological and mechanical performances of ultra-high- performance fiber-reinforced cementitious composite containing fly ash

An experimental campaign, performed on different types of ultra-high-performance fiber-reinforced cementitious composite (UHP-FRCC)—made with four replacement rates (0, 20, 50, and 70%) of cement with fly ash and cured for 1, 4, and 13 weeks—is described in this paper. Specifically, 72 cylinders were tested to measure the compressive strength and Young’s modulus of elasticity; stress-strain relationships were obtained from 72 dumbbell-type specimens subjected to uniaxial tension, and 12 beams, tested in four-point bending, provided the moment-curvature diagrams. The best UHP-FRCC was selected through an eco-mechanical analysis, capable of combining the mechanical performance with the environmental impact of concrete. When the ultimate bending moment of a beam is the functional unit of this analysis, the higher the replacement rate of cement, the better the beam performance, although material properties and structural ductility show opposite trends.