1 AIT Asian Institute of Technology

Effect of the position of inflexure points on the ultimate shear capacity of reinforced concrete beams

AuthorIslam, Md. Shahidul
Call NumberAIT Thesis no. ST-93-12
Subject(s)Concrete beams--Testing

NoteA Thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology
PublisherAsian Institute of Technology
AbstractMost of the design codes adopt a shear design formula, which is mostly derived from two point loading simple beam tests. But in actual structures the designer often faces other types of structural members, loading and sectional force distribution pattern, which are quite different from the simple case as used to formulate the design codes. This experimental study has been conducted to make clear the effects of moment distribution pattern on the shear strength of RC beams. Nine RC beams of size 15(b) cm. x 25(h) cm. and length of 340 cm. were tested. The main reinforcement (2%) was kept constant for all the beams. The beams were designed in such a way that flexural failure should not occur. The beams were placed at 220 cm. span simple supports. In order to measure the strains, stresses, poissons ratio, modulus of elasticity, Electrical Resistance Strain (ERS) gauges and Rosettes were attached to the surface of steel and concrete. To investigate the load-deflection response, dial gauges. were also placed at the top and bottom of beams. A Four point loading pattern was used except for simple loading case. By varying the location of loading position in the over hanging portion, the location of point of contraflexure was moved. To compare the results a two point loading pattern was also adopted. The results obtained indicate that moment distribution pattern influences the shear capacity as much as 70%, which is very important to be considered in designing continuous RC beams. The results were compared with the case when the beam is subjected to uniformly distributed loads, which was studied by Y. Aoyagi (1992) in Japan, where the inflexure point influenced the shear capacity as much as 40%. Finally the experimental result was compared with A CI code's detailed shear capacity calculation formula, Niwa's equation and the equation proposed by Y. Aoyagi. The proposed equation determines the shear capacity which was very closer to the experimental result other than the other existing shear capacity calculation equations.
Year1993
TypeThesis
SchoolSchool of Civil Engineering
DepartmentOther Field of Studies (No Department)
Academic Program/FoSStructural Engineering (STE) /Former Name = Structural Engineering and Construction (ST)
Chairperson(s)Aoyagi, Yukio
Examination Committee(s)Worsak Kanok-Nukulchai ;Pichai Nimityongskul ;Pennung Warnitchai ;
Scholarship Donor(s)German Academic Exchange Services (DAAD). ;
DegreeThesis (M.Eng.) - Asian Institute of Technology, 1993


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