Title: An Update on High-Strength Concrete Reinforcement In Current Codes
Author(s): R. H. Reiterman
Publication: Symposium Paper
Appears on pages(s): 79-94
Keywords: ductility; high-strength steel reinforcement; welded wire.
Eight years ago, when this engineer began in the welded wire industry, it was unclear what the capabilities of welded wire reinforcement were, let alone what the strength of materials and mechanical properties or testing methods were all about. Test books at that time placed WWR in a low strength and low ductility category. Until recently, WWR was a lesser extent, for structural applications. Now, with the latest technology and practices of cold-working rod to wire plus controlling speed and temperature of wire welding, the industry is producing reinforcement with much higher strengths and higher ductilities for more structural concrete applications. There has been excellent growth in this industry in recent years in structural WWR. It's being specified and used in many more building and bridge structures today. This paper deals principally with high strength steel reinforcement recognized and documented in the latest ACI 318 Structural Building Code and the latest ASTM Standards, A 82, A 185, A 496 and A 497. Reinforcing yield strength today are up to 80,000 psi (550 Mpa) Since AASHTO/LRFD and ACI specifications coincide for the most part, ACI references will be discussed. Being associated with the Wire Reinforcement Institute, this paper makes reference more to welded wire reinforcement. The paper will address code provisions related to all types of steel reinforcement in general. The name of the successful project game is to use the most readily available and most efficient reinforcing materials. There has been a considerable amount of performance research on reinforced slabs and paving done in recent years. Luke Snell of Southern Illinois University has done work on this subject. His paper, titled: "Cover of Welded Wire Fabric in Slabs and Pavements" was presented at another ACI Technical Session in Seattle, Washington on Jobsite Quality, Part 1. It implies that performance is achieved when steel reinforcement is placed and located property.