Based on cyclic load tests of large-scale reinforced concrete elements and assemblages, a probabilistic model of member failure is developed. The model gives the probability of survival at time t as a functional of damage ratio and dissipated energy up to t. After extension to multivariate survival of several members with correlated resistance, the model is used to calculate the safety of reinforced concrete frames subjected to given input motions. Results are in terms of the probability of local failure and of no failure anywhere in the system.

Seismic safety of reinforced concrete members and structures

The development and application of an “energy dissipation index” to characterize reinforced concrete beams under cyclic load is described. The index is designed to provide an objective measure of the response of beams with different geometries and reinforcement ratios subjected to severe cyclic loading. The effects of flexural reinforcement, transverse reinforcement, concrete strength, and load history are considered. The index is used to evaluate the results of five major experimental investigations. The energy dissipation index may be applied to both research and design. The analysis of the experimental work shows that to improve the cyclic performance of reinforced concrete beams, it is more efficient to decrease the shear stress, by increasing the beam width, than to increase the transverse reinforcement. The analysis also indicates that increasing the ratio of positive to negative reinforcement may not markedly improve the cyclic performance of a beam. Recommendations are made for the design of reinf...

Energy dissipation in rc beams under cyclic load

Seismic Damage Assessment of Reinforced Concrete Members

The efficiency of coupled wall systems to resist lateral loads is well known In order for the desired behavior of the coupled wall system to be attained, the coupling beams must be sufficiently strong and stiff The coupling beams, however, must also yield before the wall piers, behave in a ductile manner, and exhibit significant energy‐absorbing characteristics This paper reviews the current state of the art for the design of conventional reinforced concrete, diagonally reinforced concrete, steel, and composite steel‐concrete coupling beams Although not exhaustive, critical aspects of the design of these systems are presented

Behavior and Design of Reinforced Concrete, Steel, and Steel‐Concrete Coupling Beams

An experimental investigation to determine the effect of variations in displacement history sequence and magnitude on cyclic response of reinforced flexural members is presented. Testing variables included shear stress as well as displacement history. Test results indicated that both member behavior and member energy dissipation capacity were functions of applied shear stress intensity and the magnitude of maximum displacements applied to the members. It was found that cantilever beam specimens of the type tested could endure many cycles of loading for all shear stress levels as long as beam‐tip displacement did not exceed 2% of beam shear span length.

R/C Member Cyclic Response During Various Loadings

An experimental investigation to determine the effectiveness of intermediate longitudinal reinforcement in limiting shear strength decay of reinforced concrete members is presented. Test specimens consisted of fourteen exterior beam-column subassemblies. Variables included shear stress, percentage of beam transverse reinforcement, percentage of longitudinal reinforcement and shear span to depth ratio in addition to the presence of two layers of intermediate longitudinal reinforcement in half the specimens. Test results indicated that intermediate longitudinal reinforcement provided significant and useable improvement in shear strength retention for members with maximum shear stresses between three and six times the square root of the specified compression strength of concrete.

Charles F. Scribner

Papers

Strength Decay in R.C. Beams under Load Reversals

Delaying shear strength decay in reinforced concrete flexural members under large load reversals