Antiquated Structural Systems Series - structuremag.org

1 Antiquated Structural Systems Series Part 9a Open Web Steel Joists By D. Matthew Stuart, , , F. ASCE, SECB. For this Series of articles, Antiquated 1961 Introduction of the has been defined as meaning outmoded J- Series joists, which or discarded for reasons of age. In reality, replaced the S- Series however, most of the Systems that have joists. The allowable . E. been discussed are no longer in use simply tensile strength was because they have been replaced by more increased from 20 ksi innovative or more economical methods to 22 ksi. Introduction of the R. of construction. LA- Series joists to replace the Ashland Steel Products Co., Inc Ashland This article, however, deals with a meth- L- Series joists, which included an City, Tennessee); Vescom Structural od of construction that is still very much allowable tensile strength increase U.

2 Systems , Inc. Westbury, New York;. in use today. Nevertheless, the historic, from 20 ksi to 22 ksi. Introduc- Ridgeway Joists (manufactured by original construction practices described tion ht of the H- Series joists, which igprovided Continental Steel Ltd. Coquitlam, T. in this article may still be encountered y r an allowable tensile in existing structures. Therefore, the pri- Cop strength of 30 ksi. British Columbia); Northwest Joist Limited (a Division of Brittain Steel mary purpose of this Series of articles will 1962 Introduction of the LH- Series C. Limited New Westminster, British be fulfilled: to compile and disseminate a joists, which provided yield Columbia); Cadmus Long Span and Joist resource of information to enable struc- strengths between 36 ksi and Corporation (affiliated with Alexandria e U.)

3 Tural engineers to share their knowledge 50 ksi. Iron Works, Inc. Alexandria, Virginia); T- of existing Structural Systems that may no 1965 Development of a single specifica- n Chord Longspan Joists (manufactured by i longer be in use, but are capable of being tion for the J- and H- Series joists R. the Haven Busch Company Grandville adapted or reanalyzed for safe reuse in the by SJI and AISC. z and Grand Rapids, Michigan); and the marketplace of today and the future. 1966 Introduction of the LJ- Series Macomber Steel Company Canton, T a joists, which replaced the LA- Open Web Steel Joists Series joist. In addition, a single Ohio. Table 1 (please see online version;. article end note provides web address). g History specification was developed for S. provides a summary description of the The author would first like to thank the the LJ- and LH- Series joists.

4 A joists produced by these manufacturers. Engineer's Notebook Steel Joist Institute (SJI) for providing 1970 Introduction of the DLH- and In addition, some manufacturers, prior much of the material that was used in the DLJ- Series joists, which included m to becoming SJI members, produced pro- development of this article. In fact, a brief depths up to 72 inches and spans ducts other than the historical stan- history of open web joists is provided in up to 144 feet. dard SJI joist Series . Some of these the Catalog of Standard Specifications and 1978 Introduction of Joist Girders, manufacturers include: Truscon Steel Load Tables for Steel Joists and Joist Girders, including standard specifications Company Youngstown, Ohio; Macmar published by SJI. A brief summary of this and weight tables.

5 And Kalmantruss joists (manufactured by history is as follows: 1986 Introduction of the K- Series Kalman Steel Corporation, a Subsidiary of 1923 The first Warren type, open web joists, which replaced the Bethlehem Steel Company Bethlehem, truss/joist is manufactured using H- Series joists. Pennsylvania); and Gabriel Steel continuous round bars for the 1994 Introduction of the KCS joists, Company Detroit, Michigan. Table 2. top and bottom chords, with a which provided a constant (please see online version; artcile end note continuous bent round bar used moment and shear capacity provides web address) provides a summary for the web members. envelope across the entire description of the joists produced by 1928 First standard specifications length of the member. these manufacturers.

6 In addition to the adopted after the formation of SJI also recently published 80 Years of information provided in Table 2, it should SJI. This initial type of open web Open Web Steel Joist Construction. This be noted that Bethlehem Steel Company steel joists was later identified as publication includes a complete chrono- aids for the Structural engineer's toolbox also produced cold formed joists with hat the SJ- Series . logical listing of the standard specifica- channel sections for the chord members, 1929 First load table published. tions and load tables for all of the steel and Gabriel Steel Company also produced 1953 Introduction of the longspan joists, and weight tables for the Joist unique V-shaped top chord and single or L- Series joists for spans up Girders, previously made available by SJI.

7 Round bar bottom chord members. to 96 feet with depths of up to over the time period from 1928 to 2008. Additional manufacturers not included 48 inches, which were jointly This manual can be an invaluable tool for in Tables 1 and 2 include: Berger Steel approved by AISC. an engineer involved in the analysis of Company (double V-shaped chord mem- 1959 Introduction of the S- Series joists, existing buildings constructed with open bers); Armco Steel (cold formed hat which replaced the SJ- Series web steel joists. channel chord members); Raychord joists. The allowable tensile In addition, there were also a number of Corporation (cold formed hat channel and strength was increased from 18 joists produced by manufacturers that were U-shaped chord members); Republic Steel ksi to 20 ksi, and joist depths and either never members of SJI or joined it later.

8 (cold formed hat channel chord members);. spans were increased to 24 inches Some of these manufacturers in-clude: and USS AmBridge (cold formed U- and 48 feet, respectively. Ashland Steel Joists (manufactured by shaped chord members).. STRUCTURE magazine 12 June 2009. Resource Material 80 Years of Open Web Steel Joist Construction; A Compilation of Specifications and Load Tables Since 1928;. Steel Joist Institute; Myrtle Beach, South Carolina (2009). Catalog of Standard Specifications, Load Tables and Weight Tables for Steel Joists and Joist Girders; 42nd Edition; Steel Joist Institute; Myrtle Beach, South Carolina (2007).. Miscellaneous Steel Joist and Joist Girder Specifications and Load Tables; SJI Archives; Steel E. Joist Institute, Technology, Engineering, and Education Center; Myrtle Beach, South Carolina R.)

9 Another Resource Robert Higgins, , maintains a website that provides civil and Structural engineering information in the following categories: U. Out-of-print material that may be useful when working on existing facilities. Older, usually conservative methods for solving technical problems. t righ T. Public domain documents that have limited availability. o p y In summary, this is content that is difficult to Cfind anywhere else. To access it, visit U C. D. Matthew Stuart, , , F. ASCE, SECB is licensed in 20 states. Matt currently works i n e R. as a Senior Project Manager at the main office of CMX located in New Jersey, and also serves z Watch for Part 9b in an upcoming issue. as Adjunct Professor for the Masters of Structural Engineering Program at Lehigh University, T.

10 Bethlehem, PA. Mr. Stuart may be contacted at g a S. Table 1 online version web address: a Table 2 online version web address: m STRUCTURE magazine 13 June 2009. Antiquated Structural Systems Series - Table 1. Part 9a Open Web Steel Joists By D. Matthew Stuart, , , F. ASCE, SECB. Table 1: Unique Open Web Joists (Load Tables may be available from SJI). Yield Depth Span system Figure Description Chords Webs Notes . Strength (inches) (feet). E. 1 HS- Series Joists 50 ksi 8 to 24 8 to 48 Double angles Round bars Ashland 64. R. N/A LS- Series Joists 50 ksi Unknown Unknown Unknown maximum 1952 Structural T. 12'-6 to U. Cadmus 5 Longspan & Standard See Note 6 10 to 54 Split T Angles 6, 7. 108. Joists ht yrig T. 1952 to 1962 T- Co9 p Haven Busch 6 Chord Longspan See Note 18 to 88 25 to 175 Split T Angles 8, 9.