tesi A. Caggiano.pdf - EleA@UniSA - Università degli Studi di Salerno

Chapter 2. Experimental characterization of steel fiber notched concrete beamsof about 150 mm. The prismatic concrete specimens have been cured under water(100% humidity) at a constant temperature of 22 o C , for 28 days as in Figure 2.6.Table 2.3: Key proprieties of the concrete mixtures.Mixture Amount of Fibers Long fibers (FF3) Short fibers (FS7)REF - - -S100 - 05 40 kg/m 3 - 100 %S75 - 05 40 kg/m 3 25 % 75 %LS50 - 05 40 kg/m 3 50 % 50 %L75 - 05 40 kg/m 3 75 % 25 %L100 - 05 40 kg/m 3 100 % -S100 -10 80 kg/m 3 - 100 %S75 - 10 80 kg/m 3 25 % 75 %LS50 - 10 80 kg/m 3 50 % 50 %L75 - 10 80 kg/m 3 75 % 25 %L100 - 10 80 kg/m 3 100 % -Figure 2.6: Underwater curing of specimens during 28 days at constant temperature of approximately22 o C .For each mixture, three beams have been cast and tested in four-point bending. Moreover,three cubes of 150×150×150 mm 3 (Figure 2.7) have also been cast in polyurethanemolds [EN-12390-3, 2009] and then tested (in displacement control) for measuringthe compressive strength of the SFRCs at the time of testing. One of them (labeled as“white”) has been extracted before the fiber mixing, with the aim to capture the actualcontribution of fibers on the compressive response of the considered SFRC.34