The nature of fracture in REINFORCED high strength CONCRETE (HSC) MEMBERS is brittle and therefore in the seismic areas the ductility investigation of heavily REINFORCED HSC MEMBERS is important. Six REINFORCED HSC beams with different percentage of tensile and high compression bars with attaching electrical strain gauges cast and loaded experimentally up to failure. During the test, the strains on the CONCRETE middle face and on the tension and compression bars along with deflection at different points of the span length measured. Ductility of doubly REINFORCED MEMBERS was compared with the singly REINFORCED MEMBERS. The theoretical results based on ACI and CSA codes have been compared with the experimental results. In this paper, the displacement and curvature ductility of such MEMBERS are also reported.

The influence of CONCRETE strength on the ductility of RC FLEXURAL MEMBERS is investigated. Tests were carried out on beams with three ranges of CONCRETE strengths, and moment-curvature and deflection curves obtained. It is concluded that when the CONCRETE is laterally confined by closed steel ties beams with various levels of CONCRETE strength and very high tensile strength steel exhibit high ductility.

The present study investigated the FLEXURAL response and ductile behaviour of Prefabricated Cage REINFORCED CONCRETE (PCRC) beams. The Prefabricated Cage System (PCS) is fabricated by perforating hollow cold formed steel tubes or steel sheets. The resulting PCS acts as transverse and longitudinal reinforcing steel, working compositely with the surrounding CONCRETE to resist the applied loads. This new and innovative system eliminates some of the weaknesses and detailing problems inherent in traditional REINFORCED CONCRETE Construction. Nine beam specimens REINFORCED with Prefabricated Cage System were tested under monotonic loading. The effects of thickness of cold formed steel sheet and Grade of CONCRETE on parameters such as moment curvature, load deflection, ductility and energy absorption were experimentally determined. All beams exhibited considerable amount of deflection, which provide ample warning to the imminence failure. Final failure of PCRC beams were found to occur in pure bending region. The results reveal that PCRC beams show better ductile performance and energy absorption capacity due to the confinement provided by PCS. Displacement and curvature ductility factor for all beams were found and discussed in this paper.

A parametric study is undertaken to examine the effects of tension and compression reinforcement ratios and steel yield strengths, loading types and stages, CONCRETE compressive strength, craking and tension-stiffening, using the nonlinear layered finite element method. The effects of the above parameters on different behavioral aspects including the load-deflection and moment-curvature characteristics, failure load and flexured rigidity, El. Of R.C. beams are reviewed along with a comparison with the ACI code and ABA code and experimental data where available. To account for the influencing parameters, new models are proposed for estimating the felxural rigidity and the deflection of R.C. beams. The accuracy and efficiency of the proposed model is verified by comparing the analytical results with the experimental data from five different investigations. Reasonably close agreement was obtained between the test data and the computed results.

Damaged structures are not usually reliable to tolerate designed loads and therefore, it is required to retro t structural parts. The main purpose of this paper is to utilize High-Performance Fibre-REINFORCED Cement-based Composite (HPFRCC) as a high-performance material to recover the damaged beams and improve their ductility and moment capacity with experimental approaches. In addition, a retrofitting method was presented using HPFRCC. The experimental study was performed on three simply supported beams with the same dimension, materials, and reinforcement configuration. The first beam, known as the reference beam, is subjected to the pure bending condition until its failure and the others are prone to a certain amount of load according to the  final capacity of the first beam. Thereafter, two damaged beams are retrofitted using HPFRCC in the created grooves on the tensile surface of the beam; finally, these retrofitted beams are loaded to determine the bending behavior. Experimental results demonstrate that retrofitting can improve the first crack strength, load in yield condition, and maximum load capacity. Also, the proposed method increases the ductility and energy absorption of retrofitted beams.