News Detail

The Art of Formwork

10/15/2014

Deciding on a cover image for an iconic book isn’t easy. Especially when that book is celebrating its 50th year in print. The image for the new SP-4(14) Formwork for Concrete Manual was chosen to show the important role of concrete formwork in the construction process. From a network of formwork panels to a finished perimeter reliquary of architectural concrete, the images prove that formwork can be an art in itself.

(photos courtesy of Eric Petersen)

The construction of the Cathedral of Christ the Light, Oakland CA, USA, was completed in 2008, and the major superstructure element forming the Cathedral space is the glass and glulam laminated roof that rises above architectural concrete walls. The inner and outer concrete perimeter walls form two parallel circular arcs divided into six sectors by passageways directed towards the altar. Along with a concrete ceiling and floor slab, the walls create a box beam structure supporting the curved glulam timber ribs and louvers of the vaulted superstructure.

The formwork challenges for the cathedral included one-sided formwork where curved and battered architectural concrete reliquary walls intersected at acute angles, radial and annular control lines for form setting, and carefully constructed reveals to hide joints in the forming panels.

Formwork design and construction challenges like those faced at Cathedral of Christ the Light, Oakland, CA, USA, are discussed in ACI's formwork resources. The new Formwork for Concrete, is authored by David W. Johnston, Edward I. Weisiger Distinguished Professor Emeritus, at North Carolina State University, and member of ACI Technical Committee 347, Formwork for Concrete. The committee made significant contributions to the new manual, including revisions to bring it up-to-date with Guide to Formwork for Concrete (ACI 347R-14), which is reprinted in full in the appendix.

The new manual includes the current standards and practices, removes outdated or irrelevant material, adds content on new developments in formwork technology and practice, and updates the look and layout of the document.

The eighth edition is the first to be printed completely in color, with nearly 500 new color photographs and over 150 color illustrations. Span tables and design values have been updated to comply with the 2012 National Design Specification issued by the American Wood Council, and loads have been updated to reflect changes in the latest edition of ASCE/SEI 37, “Design Loads on Structures During Construction.” New formwork design examples include the use of allowable stress design, as well as load and resistance factor design. Chapter problems have also been included for the first time to make the document easier to use as a teaching tool, while still maintaining its status as a reference for practicing engineers.

"The new eighth edition marks the 50th year in print of this iconic manual," says author David Johnston.  "Revising and bringing one of ACI’s best-selling documents up to date included reference to the latest design and construction standards for guidance of the formwork designer and contractor. Expanded coverage of design methods, products, and both revised and new worked examples, will ensure that Formwork for Concrete will continue to be the most respected reference in the concrete formwork industry and an excellent teaching resource in the classrooms."

To preview the new manual, go to Formwork for Concrete. To learn more about the Cathedral of Christ the Light project, read the Concrete International article “Meeting the Formwork Requirements for a Challenging Structure.” A new CEU course is also now available: “ACI 347R-14 Guide to Formwork for Concrete (Chapter4) Design,” which addresses planning and design considerations for formwork, common design deficiencies, vertical and horizontal loads, safety factors for formwork accessories and shoring.

To order, go to www.concrete.org, or call 248-848-3800. Special discounts are available for ACI members and students.