[[wiki-architecture]] · [[Building Materials]] · [[ARCHITECTURE]] · [[000]] # Johnson bar A Johnson bar (also Johnson corrugated bar) is a type of corrugated high-carbon steel rebar used to reinforce concrete. The Johnson bar was invented by A.L. Johnson of the St. Louis Expanded Metal Company. Its specific efficacy comes from having "alternate elevations and depressions to grip the concrete," with the shoulders of the corrugations having "an inclination with the axis of the bar" to prevent slipping between the bar and the concrete. The pattern of elevations and depressions aids in the stability of the structure; even if a Johnson bar no longer is bonded to the concrete (due to vibrations, for instance, or being smeared with oil as may happen during careless construction, reducing the adhesion significantly), it will have a hold on the concrete stronger than a plain smooth-sided bar. == References == - [[History and Theory/World History/Renaissance and Baroque]] - [[Urban and Planning/Master Planning]] - [[Research, Analysis & Citations/Checklists and Templates]] - [[Building Construction/Structural Systems]] - [[Landscape/Landscape Design]] - [[Urban and Planning]] - [[Professional Practice/Codes & Standards/Standards Index]] - [[Professional Practice/Codes & Standards/National Building Code of India/Part 09 - Plumbing Services/Section 4 - Gas Supply]] - [[Professional Practice/Codes & Standards/National Building Code of India/Part 08 - Building Services/Section 5B - Escalators and Moving Walks]] - [[History and Theory/World History/Contemporary Architecture]]