Experimental Investigation on Full Scale Cast in Place R.C. Floor Strengthened with FRCC Strengthening Technique

The cast in place floors of existing buildings realized in Italy in the ‘60–70’ years are commonly made by longitudinal beams and hollow clay bricks with a top deck without internal reinforcement. Thus, they are unable to properly guarantee the load distribution function over structural members which is strongly required in case of seismic actions. Furthermore, the deck thickness of such horizontal structures is commonly less than the minimum value given by current codes (≥40 mm) in order to assume the floor as rigid in plan. The effectiveness of an innovative system, based on the use of Fibre-Reinforced Cementitious Composite (FRCC), is investigated in the paper as a strengthening technique of these existing floors. Three point bending tests on two full scale cast in place reinforced concrete (r.c.) floors have been carried out: one specimen was tested in the ‘‘as built’’ configuration; one specimen was strengthened with a new FRCC deck, about 2 cm thickness made by fibre-reinforced, shrinkage-compensated, high-strength, high-ductility, highly-fluid cementitious mortar. The main aspects related to the application procedure of the system, the experimental test setup, as well as the experimental results in terms of crack pattern, strength and deformation of the specimens are herein presented and discussed.