Assuming there are three RC beams with no shear reinforcement, with the same depth (d), web width (bw), tensile reinforcement area (As), shear span to depth ratio (a/d),... but different cross-sections (I, T-shaped and rectangular), which one has the highest shear capacity?
In shear test databases, the thickness of the flange of I and T-shaped cross-section beams is often missing. Could you provide me publications, especially with experimental works on this topic. Many thanks.
Dear Dr. Tran
That is a good question and I can not remember many experimental programs focused on the contribution of the flanges in the shear strength of beams. I am sure we can find many shear tests in T and I beams, but probably not with this specific focus. The breadth of the flanges (bf) is supposed to contribute if the flanges are in uncracked zones of the beam, i.e. simply supported T beams under shear. The design codes assumption of considering only the web (bw) is on the safe side for most design situations, but if you want to have reliable shear strength predictions, especially for bridge girders, this should be a point to be considered. Please leave here some directions if you advance on this interesting topic.
Best regards.
Mauricio
Good question! Without no doubt, the compression flanges contribute to the shear strength. There are many research programs focused on this fact. As already commented by Mauricio Ferreira, to take the compression flanges into account for the shear strength prediction is very important for the assessment of existing structures. To start reading about this topic I recommend the following papers::
Giaccio, C., Al-Mahaidi, R., & Taplin, G. (2002). Experimental study on the effect of flange geometry on the shear strength of reinforced concrete T-beams subjected to concentrated loads. Canadian Journal of Civil Engineering, 29(6), 911-918.
Ribas, C., & Cladera, A. (2013). Experimental study on shear strength of beam-and-block floors. Engineering structures, 57, 428-442. (This paper deals with an specific element completely influenced by the T-section).
Cladera, A., Marí, A., Ribas, C., Bairán, J., & Oller, E. (2015). Predicting the shear–flexural strength of slender reinforced concrete T and I shaped beams. Engineering Structures, 101, 386-398.
Best,
Toni
Dear Dr Tan,
It is actually a very interesting question. I have been working on the behavior of T and L beams subjected to torsion, shear, and flexure for some time. However, we focused on beams with stirrups not without. Thus, we found the flanges to increase the cracking and ultimate strength in cases of shear and torsion. In the case of torsion, the increase is significant, but in shear the increase is insignificant. I think Please refer to the following studies:
https://www.researchgate.net/project/Design-of-beams-with-different-cross-section-shape-under-combined-loading
Dear Dr. Tan,
I have one publication related to T-beam:
Article Shear strength of reinforced concrete T-beams without stirrups
Dear Dr. Tan,
That is a very interesting question and while flanges should have a considerable contribution in shear capacity, there is not much work focused on the specific topic. Do share if you come across relevant papers, and any of your own research.
- Badges
- Science topic