Experimental Tests on Hollow Core Slabs Made with FRC - On Shear Behavior of Structural Elements Made of Steel Fiber Reinforced Concrete - page 124

Fig. 7.4 Loading scheme adapted for the HCS test

Fig. 7.5 Test set-up. Shear
diagonal tension failure

Loads and supports were disposed into two cross lines. The shear span/depth
(a/d) ratio varied between 3 and 4.4 in Series I. In Series II there were three different
a/d ratios: 2.3, 3.4 and 8.6. Table 7.4 indicates all these parameters. In order to
facilitate their identi cation, the HCS Specimen ID took the following structure:

f Series IorII g f Amount of fibers kg ð = m 3 Þ g f a = d ratio g f a ; b ; c ; ... g

:

If there were identical HCS, they were differentiated by placing: a, b, c, etc. So,
an HCS from Series II with 50 kg/m 3 of bers, and with a/d = 3.4, which had other

identical HCS, would be: II-50-3.4b.
In order to analyze the previous precrack effect, three HCS [II-0-3.4(P), II-50-3.4
(P) and II-70-3.4(P)] were precracked before the shear test by loading the HCS with
a longer span length (a/d = 4.9) until the maximum

exure crack width in the span
reached 0.2 mm. In these precrack steps, a shear of 161kN was accomplished. After
the

fl

exure precracking tests, supports were moved to adapt them to shear tests
conditions in order to have shear failure on the

fl

fl exure precracked zone.