| Author | Khan, Shaiq ur Rahman |
| Call Number | AIT Thesis no. 253 |
| Subject(s) | Columns, Concrete
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering of the Asian Institute of Technology, Bangkok, Thailand |
| Publisher | Asian Institute of Technology |
| Abstract | This study presents a critical review of the various tie requirements for reinforced concrete columns in different codes of practice. It investigates the influence of ties on the strength and mode of failure of reinforced concrete columns, the influence of residual stresses on the behavior of reinforcing bars in compression, and the effect of inelastic deformations on the ultimate strength of reinforced concrete columns. A parallel theoretical and experimental study is conducted. As a result of the theoretical study, various expressions are obtained which determine the following:
(1) the maximum possible tie spacing as governed by buckling of longitudinal bars and required strength of ties;
(2) the minimum possible tie size as governed by required stiffness of ties;
(3) the minimum required thickness of concrete cover as governed by the bending or buckling of longitudinal bars;
(4) the increase in concrete core strength due to the lateral restraining effect of ties; and
(5) the nature and magnitude of secondary stresses developed in the concrete cover due to the distortion of the column cross section under the restraining effect of ties. The experimental investigation is designed to verify the validity of the various theoretical results obtained. It includes testing of steel bar cages, intermittently supported longitudinal bars, reinforced
concrete columns and compression tests of reinforcing bars. It is found that:
(1) The criterion obtained for the design of tie spacing governed by buckling of longitudinal bars is quite satisfactory.
(2) Creep does not influence the ultimate strength of reinforced
concrete columns if a sufficient thickness of concrete cover bars
is provided.
(3) Residual stresses do not influence the behavior of reinforcing bars in compression.
In light of the various theoretical and experimental results, a
hypothesis for the mechanism of failure of columns is offered and an improved formula for the estimation of the strength of short section reinforced concrete columns is suggested |
| Year | 1969 |
| Type | Thesis |
| School | Student Research Before 1980 |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Thesis (Year <=1979) |
| Chairperson(s) | McGuire, William |
| Examination Committee(s) | Smith, Robert B.L. ;Karasudhi, Pisidhi ;Lee, Seng-Lip |
| Scholarship Donor(s) | Asian Institute of Technology |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 1969 |
