AN INVESTIGATION OF THE LOAD-DEFORMATION CHARACTERISTICS OF REINFORCED CONCRETE BEAMS UP TO THE POINT OF FAILURE
Abstract
The relationships are established between load and deformation for beams subjected to static flexural loading. Tests were made on 33 reinforced concrete beams, 6 by 12 in. in cross section, having a span length of 9 ft, and loaded at the third points. Twenty-one beams were provided with tension reinforcements, while 12 were provided with both tension and compression reinforcement. An analysis that predicts the load-deflection diagrams for the beams consisted of expressing the conditions at the critical points of the load- deformation curves. In the yield-point equations, a transformed section and a linear stress-strain relationship for the concrete are assumed. The equations expressing the conditions at the maximum load-carrying capacity involve the values of k sub 2/k sub 1/k sub 3, k sub 1k sub 3, and epsilon sub u, where k sub 1 and k sub 2 are coefficients defining the magnitude and position of the internal compressive force in the concrete, k sub 3 is the ratio of maximum compressive strength of the concrete in a beam to the corresponding compressive strength (f sub c ') of standard test sylinders, and epsilon u is the ultimate strain in the concrete. These values were determined empirically. The value of k sub 2/k sub 1 k sub 3 was approximately 0.5, k sub 1 k sub 3 = 0.625 + 600/(f sub c' - 1500), and epsilon sub u = 0.004. Concrete strength has little effect on the energy-absorbing capacity of beams failing initially in tension but does have an effect on the capacity of those failing initially in compression. The ductility is dependent upon the reinforcing index. The midspan deflection of beams
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1952
- Accession Number
- AD0001778
Entities
People
- C. P. Siess
- J. R. Gaston
- N. M. Newmark
Organizations
- University of Illinois Urbana–Champaign