Ozarks Bound


    Cross-laminated timber comes to the Natural State in the form of student dormitories at the University of Arkansas.

    Cross-laminated timber (CLT) might be an increasingly familiar sight in cosmopolitan markets across the world, but in Fayetteville, Ark., it’s a brand new thing. And introducing it as a viable construction option hasn’t been easy. Challenges included a marathon RFP process, exhaustive communication with state and local officials, tons of pre-planning, and of course, the looming specter of the unknown.

    But Nabholz, the Arkansas-based construction company building the 202,000-square-foot mass-timber Stadium Drive Residence Halls at the University of Arkansas, is handling the challenge just fine. Expected to finish construction by fall 2019 when students arrive on campus, Nabholz looks to be the first company in the state to realize a major CLT project and, in the process, become the state’s leader when it comes to CLT construction and consulting.

    “How cool is that?” said Rob Dodd, executive vice president of operations at Nabholz.

    CLT could even become a new business line for Nabholz. The company was already offered a CLT project in Atlanta, but due to time conflicts with its current project, Nabholz had to turn the opportunity down. But the company is using its own forces for the residence halls, so when this project wraps up, the company will have an experienced team ready for the next project that is sure to come its way.

    “Those opportunities do exist and will become more apparent all the time,” Dodd said.

    To get the job, Nabholz had to first beat out the competition, and that wasn’t a given. As many as a dozen companies and/or joint ventures submitted proposals, and half of that group made it to the short list. Nabholz reps traveled to the Pacific Northwest for consultation and fact-finding and were so committed and persuasive in their talks with university officials that the case was made that the residence halls could in fact be built with CLT — a possibility in which the university had expressed an interest, if the price was right, at some point during negotiations.

    “We knew there was a desire [for CLT],” said Dodd, noting that the residence halls could have been built with the standard tandem of concrete and steel.

    Due in part to extraordinary shipping costs, Nabholz had to deal with a premium price for the CLT, but there are cost savings on the backend.

    Construction time is expected to be much shorter than with steel and concrete  — anywhere from 12 to 15 weeks as opposed to 18 to 20 weeks — and the building will not have ceilings.

    For a variety of reasons, a big change in construction came with the stair and elevator cores, which were switched from timber to cast-in-place concrete. The project contains approximately 143,644 cubic feet of timber — 110,383 in CLT and 33,261 in glulam — with a total area

     of nearly 184,000 square feet. The $79 million project will house 710 students in two residence halls — one shaped like an “L” and one shaped like a “C” — connected by a common area. The site is supported by 1,100 Rammed Aggregate Piers, which increase the bearing capacity of the soil.

    The project was designed by the collective of Leers Weinzapfel Associates, Boston; Modus Studio, Fayetteville, Ark.; Mackey Mitchell Architects, St. Louis; and OLIN, Philadelphia.

    A big part of the project centered around dealing with the unknown, particularly when it came to introducing CLT to a region for the first time. How the structure measured up to fire codes, wind and seismic loads, and plenty of other concerns, had to be fleshed out under the watchful eye of city and state officials.

    “There was a lot of engagement at every step along the way,” Dodd said.   

    The CLT panels are manufactured in Unternberg, Austria, and shipped via the port of Koper, Slovenia, near northern Italy. The glulam members are produced in Jenbach, Austria, and shipped via the port of Bremerhaven, Germany. The CLT and glulam package was provided by Austria-based partners Holzpak, a distributor, and manufacturer Binderholz Bausysteme GmbH, which pre-drills the wood prior to construction.

    When the CLT arrived in Fayetteville via truck from Memphis, Nabholz had just a two-hour window to offload the product because the site is in the middle of the state’s largest campus and near Fayetteville High School.

    Nabholz is camped out in an old fraternity house across the street from the job site. Though the building will be torn down after the residence halls are finished, for now it has full utilities so staff can cook both breakfast and lunch on premises.

    Familiarity with the site is essential as it’s adjacent to Bud Walton Arena, the university’s main venue for indoor sporting events and concerts. The arena is also the setting for the annual meeting of Walmart shareholders. Since access to the venue’s loading docks must remain open, Nabholz staff at times must juggle bulldozers, cranes, busses, and tractor trailers.

    All the hard work, however, will be worth it in the end.

    “They’re beautiful, warm buildings,” Dodd said of CLT.

    To earn 1 Professional Development Hour, watch the video about this project and take a 10-question quiz at https://csengineermag.com/continuing-education.

    Richard Massey is director of newsletters and special publications at Zweig Group and editor of The Zweig Letter. He can be reached at rmassey@zwieiggroup.com.