Study of early age behavior of fiber-reinforced cement- based materials containing expansive agent

Aim of this experimental work was to characterize the early-age behavior of several FiberReinforced Cement-based Composites (FRCCs) containing CaO-based expansive agent. The influence of different amounts of fibers (namely 2.0%, 1.75% and 1.5% by volume of FRCC) on the mechanical performance of FRCCs was investigated. The attention was focused on the strength development at early ages, with tests carried out at 0.25 (i.e. 6 hours, corresponding to time of demolding), 1, 2, 7 up to 28 days of curing. FRCCs were characterized at both fresh and hardened state, by measuring fresh consistency as well as compressive and flexural strength up to 28 days on prismatic specimens. The addition of different amounts of fibers did not influence the values of compressive strength, while there is a difference of about 4 MP in terms of 28-day residual flexural strength between the mixture with 1.5% and 2% of fibers. A minimum value of 20 MPa was achieved for the 28-day peak flexural strength in all cases.