| Author | Likhit Kittisatra |
| Call Number | AIT Thesis no. 182 |
| Subject(s) | Concrete beams--Testing
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in the SEATO Graduate School
of Engineering, Bangkok, Thailand. |
| Publisher | Asian Institute of Technology |
| Abstract | Thirty-four reinforced concrete beams, six-inch square and six
feet long were tested under various combinations of bending and twisting moments. The size and spacing of both longitudinal and transverse reinforcing bars were varied. The beams were loaded from zero up to maximum load in approximately twelve increments and subsequently strained beyond first signs of crushing of the concrete until a marked decrease in sustained load was obtained. The ratio of bending to twisting moment was maintained
constant throughout any given test. Load was applied such that the moments were constant over the middle third of the beam and bending and twisting rotations over this length were measured throughout each test. The rotation capacity of the beams was found to increase as the
spacing of the stirrups was decreased. The mode of failure in combined bending and torsion was characterized in every case by tension cracks on the bottom face travelling up the sides of the beams at an increasing angle to the vertical as they approached the top of the beam. Finally, the concrete crushed on the top surface along a line approximately joining the ends of the major tensile cracks on the sides of the beam. Calculated failure moments using the theory proposed by WALSH et
al (1966b) were close to the observed failure moments.
The lines of action of the idealized axes of rotation calculated using WALSH et al (1966b) theory were in general close to those obtained from the measured rotations. For a constant ratio of transverse to longitudinal reinforcement it was found that the tangent of the angle of inclination of the idealized axis of rotation with the transverse cross section of the beam was almost directly proportional to the ratio of the applied twisting to bending moment. |
| Year | 1967 |
| Type | Thesis |
| School | Student Research Before 1980 |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Thesis (Year <=1979) |
| Chairperson(s) | Jackson, N. |
| Examination Committee(s) | Lorell, William.W. ;Chiu, Arthur N.L. |
| Degree | Thesis (M. Eng.) - SEATO Graduate School of Engineering, 1967 |
