Structural Engineering: RE: masonry development length equations

The 1999 version of ACI 530 used ld=0.002*db*fs for allowable stress design and didn't include limit states design; the 2005 version and the version recently out for public comment uses an allowable stress design equation consistent with the strength design equation. I don't have the other interim versions handy, but I seem to recall one version having different equations for ASD and strength design - I questioned how the rebar knows which method it was designed by!

Bill Sherman

CH2M HILL / DEN

720-286-2792

From: Scott Maxwell [mailto:smaxwell@umich.edu]
Sent: Tuesday, July 17, 2007 5:03 PM
To: seaint@seaint.org
Subject: RE: masonry development length equations

Your best bet off hand would be to look at the recent versions of the ACI 530. If you don't have previous versions, I might find sometime to summarize the iterations (I don't have them memorized). As to the near future, the 530-08 revision were just out for public comment. I could potentially dig them up as well if you did not take a look at them when I let the list know about the public comment period. Other than that, you would need to attend the MSJC/530 committee meetings or know someone who does. The 2011 cycle is about to get started.

Regards,

Scott

Adrian, MI

-----Original Message-----
From: Christopher Banbury [mailto:cbanbury@arkengineering.net]
Sent: Tuesday, July 17, 2007 1:26 PM
To: seaint@seaint.org
Subject: masonry development length equations

Where can I find information on the recent history and near future of the ACI development length equations for masonry reinforcement?

The Florida Building Code references ACI 530-05 equation 3-15 for strength design but for allowable stress design they have replaced ACI 530-05 equation 2-9 with ld=0.002*db*fs.

Thanks.

Christopher Banbury, PE

President

Ark Engineering, Inc.

PO Box 10129, Brooksville, FL 34603

22 North Broad ST, Brooksville, FL 34601

Phone: (352) 754-2424

Fax: (352) 754-2412

www.arkengineering.net