Masonry Magazine April 1972 Page. 8
Loadbearing Masonry Seminar
Wall thicknesses in most of these structures vary from 12" to 15" at the base, tapering to 6" to 8" in upper walls. Toennies compared this with the historic 16-story Monadnock Building in Chicago-completed in 1891 and the last of the "premier" loadbearing masonry buildings-whose walls are 6 ft. thick at the base.
Toennies indicated it takes an average of one work-week to complete one floor of loadbearing masonry design, and as little as three to four days in some instances. Average per-square-foot cost, he found, has ranged between $10 and $14.50, including all appurtenances and site development.
Alan Yorkdale slide-illustrated some of the prominent loadbearing masonry projects being carried out here as well as abroad. He gave northern European nations much of the credit for pioneering this concept, mainly because of lower labor rates and an abundance of masonry materials and the shortage of steel in that section of the world. "The need was there and they developed it early," he said, "Now the need is in the United States and we are catching up and surpassing them at this point."
He concluded his discussion with a slide presentation of engineering formulas pertaining to brick masonry design; bond, shear and compression strengths, and the comparative ultimate costs of building walls.
Jumbo brick interior walls of the Broadview Apartments are attractive as well as being virtually maintenance-free. Residents there have expressed their liking for the "warm" feeling generated by brick.
Luncheon speaker Albert W. Isberner, Jr., Research Engineer for the Portland Cement Association, Skokie, III., outlined the physical properties of mortar as well as the design aspects of masonry units. His slide presentation covered mortar specifications, grouting, and means of avoiding efflorescence.
Isberner also briefly discussed automated machinery presently being used to lay up masonry walls. He said, however, to his knowledge only three such devices are under development in this country and that they are "still purely in the experimental stage."
Afternoon sessions were devoted to case studies of the Broadview Apartments, Kankakee, III., and the Carson Inn-Nordic Hills project in Itasca, III. Speakers for the Broadview development were Arthur Prokaski, Vice President & General Superintendent, Schless Construction Co., Inc., general and mason contractor and developer, and Architect Wayne W. Johnson, AIA, Seigfried, Johnson & Associates.
Loadbearing masonry was selected for the Broadview development both for its beauty and construction economy.
This eight-story high-rise for senior citizens features jumbo brick with extensive use of exposed concrete block and brick in the public areas and stairwells. The Kankakee County Housing Authority is the owner.
Started in April, 1971 and completed in February, 1972, this 70,000 sq. ft. structure has 100 units. The relatively maintenance-free corridors contain loadbearing exposed concrete block on the six upper floors and exposed brick on the first two floors and in all elevator lobbies.
Loadbearing masonry was selected for this job, according to Architect Johnson, because "it enabled us to design the nicest looking building at the least cost." The recommendation for its use was made by Schless Construction Co. and followed through by Structural Engineer Norman H. Meyer & Associates and the architects.
The recommendation took into consideration the opportunity provided by loadbearing to start finishing lower floors while work moves along overhead. Interim financing, which is possible with this system, and shorter construction time than with other materials and systems also influenced the decision.
"With this happy experience behind us," Johnson said, "we plan to give serious consideration to the additional benefits of through-the-wall loadbearing masonry on future projects." He indicated that his firm has already begun work on a similar project in Wisconsin.
The case history on the Carson Inn-Nordic Hills undertaking was presented by Martin Wellman, Vice President for Construction, Carson International, Inc., Itasca, Ill.; John T. Holsman of John T. Holsman & Ronald H. Holsman Architects, Denver, and Clarence M. Esche, President, Esche, Lee & Coy, Inc. (MCAA), mason contractors, Arlington Heights, III.
Carson Inn consists of two nine-story guest room towers.
Hexagonal-shaped twin towers of Carson Inn / Nordic Hills project are moving along at a rapid construction pace with completion scheduled for May, 1972.