In late December 2009, the Department of Building and Housing (DBH) released 'Practice Advisory 11 Grade 500E reinforcing steel – good practice'. (http://www.dbh.govt.nz/guidance-information#pa11)
The online publication provides guidance on the use of 300E and 500E reinforcing steel. Topics covered include properties and characteristics of reinforcing steel, minimum bend diameters, advice on fabrication processes, a good practice guide, and more.
The updated advisory includes information on new research into bend diameters.