Some technical terms about construction
1.When a reforcing bar is bent at an angle of 90 degrees, it extends 2 diameters.
2.When a reforcing bar is bent at an angle of 90 degrees, there is an extendion rate.
Please help me check the above two seentences and correct the mistakes( if any)?
3.Do you say " to cast a slab" or " to pour concrete for a slab" or " to spill concrete for a slab"?