IBC Design 721.1(1) 1-9.1

1-Hour Fire Rated Steel columns and all of primary trusses — Minimum W8x35 wide flange steel column (w/d >= 0.75) with…

IBC Table 721.1(1), Item 1-9.1 (Steel columns and all of primary trusses): protection by Minimum W8x35 wide flange steel column (w/d >= 0.75) with each web cavity filled even with the flange tip with normal weight carbonate or siliceous aggregate concrete (3,000 psi minimum compressive strength with 145 pcf +/- 3 pcf unit weight). Reinforce the concrete in each web cavity with a minimum No. 4 deformed reinforcing bar installed vertically and centered in the cavity, and secured to the column web with a minimum No. 2 horizontal deformed reinforcing bar welded to the web every 18" on center vertically. As an alternative to the No. 4 rebar, 3/4" diameter by 3" long headed studs, spaced at 12" on center vertically, shall be welded on each side of the web mid-way between the column flanges. Minimum insulating material thickness — 1-hr: See Note n". Prescriptive protection from the adopted building code — see table footnotes for conditions.