Amendment (Chapter 2.11/pg. 122)
A reader kindly drew an error to my attention. It is not a serious omission, but nevertheless may cause a little confusion to those familiar with reinforcement bar areas.
In the calculation for bar area on page 122 in the main book, 20mm bars were quoted to have an area of 157 mm², which is incorrect. It should be 314mm².
The calculation has been amended to suit 16mm reinforcement bars, and corrected to suit. This will be covered in the fourth edition, due out in summer 2017. See below.