ACI Introduces New Tilt-Up Panel Design Guide
Those familiar with the document development at ACI know that it is not a speedy process. In part, that is intentional. It allows ample time for review, dissenting opinions, and for resolution of differences. It is also due to the fact that committees meet but twice a year and the industry experts staffing those committees are volunteers with regular full-time jobs.
The brand new, first-ever, ACI 551.2R- 10, Design Guide for Tilt-Up Concrete Panels Is one of those documents. Design Guide for Tilt-Up Concrete Panels, however, is a landmark for the Tilt-Up industry. Not only is it the first Tilt-Up Design Guide from ACI, it is the first consensus document on Tilt- Up panel engineering.
Site cast Tilt-Up construction has existed in North America for over 50 years but there has been no standard process for designing the slender walls employed in the Tilt-Up approach. ACI-318 covered some of the basic design requirements but this document expands on those provisions and provides a comprehensive procedure for the design of slender walls. It also provides design recommendations for various support and load conditions not covered in ACI-318.
There have been design publications in the past including TCA’s Tilt-Up Construction and Engineering Manual, which TCA purchased from Hugh Brooks many years ago – and updated several times. The Portland Cement Association also had a document covering some aspects of engineering but it became outdated many years ago. The Design Guide for Tilt-Up Concrete Panels is state-of-the-art and presents a unified approach to the engineering design of Tilt-Up panels – something that has been lacking in our industry.
I’m not an engineer (I’m an architect) so I won’t attempt to explain the document. I suggest you purchase a copy (from TCA of course), familiarize yourself with its approach, and provide the committee and TCA with feedback. What does this hold for the TCEM (Tilt-Up Construction and Engineering Manual)? TCA is moving toward two separate new publications. One will be an updated construction manual which provides new and updated information based on chapters 1-8 of the existing TCEM and a second manual which provides design examples presented in the new. The Design Guide for Tilt-Up Concrete Panels does not provide examples of application of the design principles nor does it deal with the entire building – that has been left to the TCA and other outside sources. The TCEM presents building design examples, not just panel designs and we will continue to publish it until the examples for the new guide are developed.
TCA is also working with ACI to put together a series of seminars around the country to present, explain, and solicit feedback on the document (including a short acronym so I don’t have to spell out Design Guide for Tilt- Up Concrete Panels every time I refer to it).
This is the first attempt at a document of this scope in the industry and we want and welcome your feedback. To order your copy of the document, log on to the TCA web site at www.tilt-up. org and visit our resources page.
Ed Sauter, Executive Director