A study of the shear capacity of reinforced concrete beams with inclined stirrups as influenced by the inflexure points | |
| Author | Adhikary, Bimal Babu |
| Call Number | AIT Thesis no.ST-95-5 |
| Subject(s) | Concrete beams--Testing Strength of materials |
| Note | A thesis submitted in partial fulfillment of the requirement for the Degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. ST-95-5 |
| Abstract | Experimental and analytical studies on the shear capacity of reinforced concrete beams with inclined shear reinforcements were carried out to clarify the effect of inflexure points on the shear span. Full scale tests on 12 RC beams of size of 16 cm(b) x 25 cm(h) and length of 340 cm were carried out up to failure. The beams were designed to fail in shear such that no flexural failures occurred. The beams were reinforced in shear at an inclination of 45° to the beam axis with 6 mm SR24 bars in shear failure region and with 9 mm SR24 vertical bars in rest of the portion. By varying the loads on overhang portion, inflexure point was varied. The load deflection response, cracking patterns, load-strain relationship in stirrups and main reinforcements were recorded. The loads for flexural crack, diagonal crack, yielding of stirrup and final failure were observed. Analytical study based on finite element method using the nonlinear finite element program for two dimensional reinforced concrete structures (modified WCOMR) was carried out. The beams were discretized into the mesh of 4-node isoparametric elements. All the results obtained from numerical analysis resembled closely with the experimental results. It was found that presence of inflexure point on the shear span increases the ultimate shear strength of the beams in comparison to the beams without inflexure point on their shear span. The increment was as much as 35% but the average for all the beams was around 25% which was little higher than that in the cases of beams with vertical stirrups obtained in the previous work. Finally by using the formula proposed by Aoyagi, Y. and Endo, T.(1992) to compute the shear taken by concrete and using the concept of truss mechanism to compute the shear taken by stirrups, a formula to calculate the ultimate shear capacity of RC beams with shear reinforcement was proposed. The shear capacities computed from proposed formula were compared with experimental results and various current codes of practices. It was found that the proposed formula seemed to give the best fit to experimental results compared with the current codes of practices and the difference between the results obtained by the proposed formula and experimental ones was 25% in an average. |
| Year | 1995 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. ST-95-5 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Aoyagi, Yukio |
| Examination Committee(s) | Taweep Chaisomphob;Mutsuyoshi, Hiroshi |
| Scholarship Donor(s) | German Academic Exchange Service (DAAD) |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1995 |