DYNAMIC SHEAR STRENGTH OF REINFORCED CONCRETE BEAMS. PART 3
Final rept. Jul 1966-Nov 1968
NAVAL CIVIL ENGINEERING LAB PORT HUENEME CA
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Theoretical and experimental work was done to study shear and diagonal tension in rectangular, reinforced concrete beams on simple supports and subjected to uniformly distributed dynamic and static loads. The objective was to determine criteria for the minimum amount of web reinforcement required for developing the ultimate flexural resistance of beams, and to determine the difference between these criteria for static and dynamic loading. The main portion of the experiment work consisted of testing 53 beams 29 were loaded dynamically and 24 were loaded statically. Emphasis was placed on effectiveness of web reinforcement 47 beams contained web reinforcement and six had none. All of the beams were tested in the NCEL blast simulator. Static loads were applied using compressed air, and dynamic loads were applied using the expanding gas from detonation of Primacord explosive. All of the beams were slender, and all of them were rectangular except 10 that were I-shaped. It was found that the shear and the shear strength in the beams were greaterunder dynamic load than under the same amount of load applied statically. Furthermore, it was found that a beam with enough web reinforcement to force flexural failure under static loading might not have enough to force flexural failure under dynamic loading. The theory was found to predict behavior up to the usable ultimate shear strength within normal engineering accuracy, and to provide a fair estimate of the time, location, and mode of failure.
- Structural Engineering and Building Technology