Strength and Stiffness of Reinforced Concrete Panels Subjected to Membrane Shear, Two-Way and Four-Way Reinforcing

摘要

This report presents results of an experimental program to investigate seismic shear transfer in a cracked reinforced concrete containment vessel. Both orthogonal (two-way) and four-way reinforcement patterns are studied. The test specimen was designed and constructed to simulate the stress state in the wall of a pressurized containment subjected to tangential shear stresses induced by an earthquake. 24 specimens were tested with a number of loading histories: constant biaxial tension followed by monotonic shear to failure, constant tension followed by incrementally increasing cyclic (reversing) shear to failure, shear followed by increasing tension, and simultaneous shear and tension. Four levels of biaxial tension, ranging from 0 to 0.9fy were used. Results are given for strength, stiffness, development of cracking, and degradation effects produced by cyclic shear. Comparisons are made between the results of an earlier investigation with higher steel ratios, between the 2-way and 4-way reinforced specimens, and between model tests and the panel tests, and design recommendations are made for both strength and stiffness.