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61 Table 29. (Continued). Article Brief Summary of Changes C5.8.3.3 Nominal Shear Resistance Identifies that transverse reinforcement with specified yield strengths up to 100.0 ksi may be used in applications with flexural shear without torsion. 5.8.3.5 Longitudinal Reinforcement Permits longitudinal reinforcing steel with specified yield strengths up to 100.0 ksi. 5.8.4.1 Interface Shear Transfer, General Clarifies that fy is limited to 60.0 ksi in Equation 5.8.4.1.3. 5.10.2 and C5.10.2 Hooks and Bends Permits hooks with specified yield strengths up to 100.0 ksi with transverse confining steel in Seismic Zone 1. 5.10.6.1 and C5.10.6.1 Transverse Permits spirals with specified yield strengths Reinforcement for Compression Members, up to 100.0 ksi in Seismic Zone 1. General 5.10.11.1 Provisions for Seismic Design, Permits the use of reinforcing steel with General specified yield strengths up to 100.0 ksi in Seismic Zone 1. 5.11.1.1 and C5.11.1.1 DEVELOPMENT Permits the development length equations to be AND SPLICES OF REINFORCEMENT, used for reinforcing steel with specified yield Basic Requirements strengths up to 100.0 ksi. 5.11.2 and C5.11.2 Development of Reinforcement 5.11.2.1 Deformed Bar and Wire in Tension Requires transverse confining steel for development of reinforcing steel with specified yield strengths greater than 75.0 ksi. 5.11.5 and adds C5.11.5 Splices of Bar Permits splices in reinforcing steel with Reinforcement specified yield strengths up to 100.0 ksi and 5.11.5.3 and C5.11.5.3 Splices of requires transverse confining steel. Reinforcement in Tension Table 5.11.5.3.1-1 Classes of Tension Lap Requires transverse confining steel in splices Splices of reinforcing steel with specified yield strengths exceeding 75.0 ksi. area of reinforcement in the secondary direction. However, to model concrete behavior and an elastic-perfectly plastic steel spacing requirements of 5.7.3.4 will limit how much the area behavior (having Es = 29,000 ksi), is shown to be appropriate for of the primary reinforcement can be reduced, and thus, also values of fy 100 ksi. To ensure ductility, steel strains correspon- limits the permitted reduction in the secondary reinforcement. ding to tension- and compression-controlled limits (defined in No change is proposed. 5.7.2.1 of specifications) are recommended as follows: Current Recommended 3.2 Conclusions 5.7.2.1; No Limits for Recommended High-Strength Based on the presented experimental and analytical studies, Changes Reinforcement the following conclusions are drawn. The conclusions are fy 60 ksi fy = 100 ksi grouped based on the main tasks of this work. Tension-Controlled t 0.005 t 0.008 Section Compression-Controlled t 0.002 t 0.004 3.2.1 Yield Strength Section Values may be interpolated A critical objective of the present work was to identify an between limits. appropriate steel strength and/or behavior model to adequately capture the behavior of high-strength reinforcing steel while These strain limits were developed through a rigorous ana- respecting the tenets of design and the needs of the designer. A lytical study of 286 cases, which included seven different grades value of yield strength, fy , not exceeding 100 ksi was found of reinforcing steel, three concrete strengths, and multiple sec- to be permissible without requiring significant changes to the tion geometries. Six large-scale beam specimens reinforced specifications. with A1035 reinforcing steel confirmed the appropriateness of the proposed tension- and compression-controlled limits. All beam specimens met and exceeded their designed-for strength 3.2.2 Flexure and ductility criteria and exhibited predictable behavior and The current specifications design methodology for flexure, performance similar to beams having conventional reinforcing that is, a simple plane sections analysis using stress block factors steel.