Uzel, A. | Bentz, E.C. | Collins, M.P.

Conference Object | 2015 | Concrete - Innovation and Design: fib Symposium Proceedings , pp.85 - 86

It is common to construct footings without shear reinforcement and hence the safety of such important members depends upon the accuracy of shear design provisions. There is very little knowledge on the shear behaviour of large footings under indirect loading, where the support reaction does not apply a compressive force to the top or bottom surface of the member. In practice, this type of loading situation may occur at the heel of a retaining wall. This paper summarizes an experimental program, which was carried out to investigate the difference in shear strength between direct and indirect loading. Experimental results of footings . . .with different thicknesses, slenderness ratios, and applied loading patterns, have shown that there is still a distinct strut action even under indirect loading. A strut-and-tie model is proposed to predict the shear capacity of indirectly loaded large footings with low slenderness ratios. Furthermore, experimental results are compared to shear strength predictions based on Canadian Code CSA A23.3-04 and flb Model Code 2010 Daha fazlası Daha az

Daniş, E. | Uzel, A.

Conference Object | 2019 | Proceedings of the fib Symposium 2019: Concrete - Innovations in Materials, Design and Structures , pp.1872 - 1877

In the shear design of non-slender members, significant vertical compressive stresses occur by the loading and support conditions. Sectional models which ignore the beneficial effects of these vertical compressive stresses underestimate the shear strength of such members. In this study, a simple expression is derived to calculate the vertical compressive stress at mid-depth of point loaded non-slender beams and the influence of these compressive stresses is incorporated into the shear design procedures of fib Model Code 2010. ACI-DAfStb evaluation databases of shear tests on point loaded simply supported reinforced concrete members . . .with and without stirrups, are employed to evaluate the accuracy of this proposed sectional analysis method. It is concluded that sectional analysis with vertical compressive stresses yields better results than the sectional method in the fib Model Code 2010. © Federation Internationale du Beton (fib) - International Federation for Structural Concrete, 2019 Daha fazlası Daha az

Uzel, A. | Bentz, E.C. | Collins, M.P.

Conference Object | 2013 | fib Symposium TEL-AVIV 2013: Engineering a Concrete Future: Technology, Modeling and Construction, Proceedings , pp.293 - 296

Reinforced concrete footings are generally lightly reinforced large members supported on soil and often designed without shear reinforcement. There is now strong evidence that for lightly reinforced slender members without stirrups, the shear stress at failure decreases as the members become larger. On the ether hand the applied shear in footings is transmitted to the soil primarily by a diagonal compressive strut action and many footings in practice are short enough that the beneficial effects of this load carrying mechanism counteract the size effect in shear. This paper describes an experimental program designed to study the infl . . .uence of member thickness, slenderness ratio and loading conditions on one-way shear behaviour of large footings. The experimental results show that in most cases the shear capacity of footings was considerably greater than that predicted by the current concrete codes. The results also indicate that there is a significant size effect that influences the shear strength of large footings Daha fazlası Daha az

Uzel, A. | Bentz, E.C. | Collins, M.P.

Conference Object | 2014 | Engineering for Progress, Nature and People , pp.137 - 144

In nature, most loads act as uniformly distributed loads. However, during the last 60 years of experimental research on the shear behaviour of RC members, only a small number of tests involved beams subjected to uniform loads. Recent research on members subjected to uniform loading has shown that there is considerable difference in shear behaviour between uniformly and point loaded members. Furthermore, whether the uniformly distributed loading is applied on the tension or compression face of the member is important from the standpoint of shear design. This paper will present the results of an experimental program along with results . . . from the literature and suggest analysis methods, which can accurately predict shear strength of RC members under uniform loads Daha fazlası Daha az