Designing the steel is half the job. Placing it is the other half.

Knowing the size and spacing of the rebar is only the start. The book shows the part most texts skip: how the cage actually goes together, how long heavy bars are supported and lowered into the forms, and how you keep foot access across a slab while you pour it. These are the steps you only know if you have built one, more than once, and fixed what went wrong.