Civil Engineering Reference
In-Depth Information
Figure 17.13
The negative moments shown in Figures 17.12 and 17.13 were calculated at the cen-
terlines of the supports. At these supports, the cross section of the slab beam is very large
due to the presence of the column. At the face of the column, however, the cross section is
far smaller, and the Code (13.7.7) specifies that negative reinforcing be designed for the
moment there. (If the column is not rectangular, it is replaced with a square column of the
same total area and the moment is computed at the face of that fictitious column.)
The design moments shown in Figure 17.14 were determined by drawing the shear
diagram and computing the area of that diagram between the centerline of each support
and the face of the column.
Figure 17.14
