Reinforcement grades higher than 75 ksi (520 MPa) are not allowed in members that form plastic hinges due to a lack of information on material characteristics and on the seismic performance of columns constructed with high-strength steel (HSS) reinforcement. This research investigated the performance of reinforced concrete columns containing Grade 80 (minimum yield strength of 80 ksi [550 MPa])...

Describing the moment rotation (M/θ) behavior of reinforced concrete (RC) hinges is essential in predicting the behavior of RC structures under severe loadings, such as under cyclic earthquake motions and blast loading. The behavior of RC hinges is defined by localized slip or partial interaction (PI) behaviors in both the tension and compression region. In the tension region, slip between the ...

This paper reports on nine relevant applications of FRP composites in concrete structures in the United States. Strengthening of concrete members with externally bonded FRP laminates or near surface mounted (NSM) bars has received remarkable attention. FRP materials have been used in small projects and some multi-million dollar projects for strengthening parking garages, multi-purpose conventio...

Commercial finite element software generally includes dedicated numerical models for the nonlinear response of concrete under loading. These models usually include a smeared crack analogy to account for the relatively poor tensile strength of concrete, a plasticity algorithm to facilitate concrete crushing in compression regions and a method of specifying the amount, the distribution and the or...

This paper presents two shear tests of -in. diameter cast-in anchors embedded in the plastic hinge zone of reinforced concrete columns. Design codes, such as ACI 318-14, require special reinforcement for concrete anchors in concrete that could be substantially damaged during an earthquake. The test anchors in this study were equipped with the anchor reinforcement recommended and verified in the...

This paper reports on the key features of the “Guide for the Design and Construction of Concrete Reinforced with FRP Bars” issued by the American Concrete Institute (ACI). For new construction, FRP bars have been used as the internal reinforcement in concrete members to replace conventional steel rebars for a host of reasons. The principles for design and construction were first established and...