where A = area of concrete surrounding each bar (A = A8/n, where n is
the number of bars) in square inches, and the steel stress fs is in psi (1 in =-
25.4 mm; 1 psi = 0.00689 N/mmz). The measured maximum crack widths
from which Eq. 10.60 was derived showed a scatter of up to i40‘X, from the
equation. To obtain the maximum crack width at the extreme tension fiber
for beams reinforced by deformed bars, Kaar and Hognestadw modified
Eq. 10.60 to