Influence of the longitudinal reinforcement on the shear strength of one-way concrete slabs

Abstract

The shear strength of one-way slabs is studied in this paper via an experimental program performed by the authors and the analysis of a shear test database. The experimental program, in which six slabs and three beams divided into two series were tested, was developed to study the influence of the slab width, the longitudinal reinforcement spacing and the bottom transverse reinforcement on the shear response of one-way slabs. The results showed that the width and the bottom transverse reinforcement do not significantly affect the shear response of the slab. The shear failure surface depends on the longitudinal reinforcement spacing because a three-dimensional resisting mechanism formed as a result of large bar spacing. A database of 79 tests on slabs was analysed to study in depth the influence of these parameters on the shear strength of one-way slabs. Finally, different shear procedures were applied to the database to evaluate their reliability to predict the shear strength.

One‐way shear strength of wide reinforced concrete members without stirrups

“…The database of wide members under line loads in the member width and under different load arrangements in the span direction contains 170 test results of specimens with b/d > 1 ratio, which is the criterion for the definition of experiments on wide beams and slabs. The tests were conducted by: Adam et al, 53 Adam et al, 26 Adam et al, 54 Aster and Koch, 55 Bui et al, 56 Conforti et al, 9,57,58 Furuuchi et al, 59 Ghannoum, 60 Gurutzeaga et al, 8 Heger and McGrath, 61 Jäger, 62 Jäger and Marti, 63…”

“…36 This relation is more evident and was validated by experimental measurements for structural members and load arrangements whose aggregate interlock is the main shear-carrying mechanism in the cracked section. 83 Another aspect usually neglected in experimental analyses of beams and wide members 8,84 is the effect of the degree of rotational restraint d r of continuous members in the internal support. Reiβen 32 reported some results limited to members under CL.…”

“…Such beams may not be representative for wide members, whose b/d ratio is higher than 1. A database analysis conducted by Gurutzeaga et al 8 revealed the member width b does not appear to influence the shear strength of wide members significantly. On the other hand, Conforti et al 9 observed shear strength increases approximately 25% when the b/d ratio increases from 1 to 3.…”

“…We propose joining the available test results of wide members with shear failures and discussing their behavior under different load arrangements and support F I G U R E 2 Differences in the cracking pattern of members with different b/d ratios identified by Conforti et al 9 conditions/structural systems. In comparison to the databases developed by Gurutzeaga et al 8 and Conforti et al, 9 our database includes a more significant number of test results (170) and different structural systems, which were used for the identification of the main parameters that influence the shear strength of wide members. Furthermore, these results were used in an assessment of semiempirical and mechanical-based models of shear strength according to: (a) the structural system, (b) b/d ratio, and (c) shear slenderness λ.…”

Nośność Na Ścinanie Zginanych Elementów Betonowych Zbrojonych Prętami Kompozytowymi FRP W Świetle Wybranych Procedur Obliczeniowych

“…Ponieważ, jak wykazały badania przedstawione w pracach [19] i [40], szerokość elementu ma nieznaczny wpływ na jego nośność na ścinanie, opisane procedury mogą mieć zastosowanie zarówno do belek jak i płyt betonowych.…”