In my last blog dated November 13th, I had said that I would discuss a few recent projects that utilized “big beams” rolled the hard way (x-x axis) as the main structural element(s) in the building design. As you may recall, it was determined that the term “big beam” would start with a W24 x 55 up to a W44 x 335.
The first project we will focus on is the Minot International Airport, Minot, North Dakota. This project originally bid in June, 2013. At bid time, bender/rollers were requested to quote numerous “big beams” rolled the hard way. There were W24 x 68’s, W27 x 84’s, but the majority were W30 x 90’s. These beams were to be rolled the hard way to a 75’-0” outside radius. Upon careful review of notes and records from previous W30’s which were rolled the hard way, the bender/roller decided to quote W30 x 116’s in lieu of the W30 x 90’s. The W30 x 116’s are in what is called a “family” of beam size(s). W30 x 90 through W30 x1 48 are considered to be in the same “family”. (Beam depth and flange width are similar while the flange and web thicknesses vary slightly). A W30 x 173 is not in the same family as W30 x 90’s to W30 x 148’s as the flange width of the W30 x 173 is 15 inches, while the W30 x 90’s to W30 x 148’s is 10.5 inches. Thus the W30 x 116’s quoted at bid time to the steel fabricators are in the same family as the W30 x 90’s. It is important to note that because the bender/roller quoted a heavier beam at bid time, the steel fabricator, (if he used the quote supplied by the bender/roller) would have an accurate quote for the curved steel included in their bid.
Months later, a steel fabricator was awarded the project, and a bender/roller was chosen by the steel fabricator to supply the curved material for the project. Not only were there W24 x 68’s, W27 x 84’s and W30 x 90’s rolled the hard way, but there were also rectangular tubes (TS10 x 4’s and TS16 x 8’s) that were rolled the hard way. However, our focus is the “big beams”.
The bender/roller purchased all of the W30 x 116’s direct from a steel mill. All of these beams were produced from the same steel mill, at one time, which was important for this project as there were 86 – W30 x 116’s in lengths from 45ft to 73ft. A total of 228 tons!
The W30 x 116’s were received by the bender/roller in March and April 2014. The steel fabricator released the W30 x 116’s for production (curving/rolling) in three phases. The first phase was released for production April 30, 2014. All 3 phases were curved and shipped by August 15, 2014.
Upon receipt of the curved beams, the steel fabricator fabricated the curved beams, delivered the curved beams to the job site in Minot, North Dakota, at which the curved beams were erected. As of today, all of the curved “big beams” have been erected. The estimated completion date of the main structure is Fall 2015.
In this case, early involvement by the bender/roller was critical to the project. When I asked the machine operator what were his thoughts about rolling a W30 x 90 to the 75′-0″ outside radius, his reply was a simple “no way!”