A closure strip in a slab is

• A. Pour back when infilling after panel erection.
• B. Pour back before panel erection.
• C. Pour back during finishing.
• D. Remove after panel erection.

Answer: (A)

The key idea is that a closure strip is a temporary filler placed in the joint between tilt-up panels to close the gap so the infill concrete can be poured properly. After the panels are erected and aligned, you infill the space between them, and the closure strip is poured back into the joint with that concrete, creating a continuous wall surface and a controlled, clean edge. This poured-back fill helps tie the panels together, control joint width, and prevent leaks or honeycombing at the joint. Pouring before panel erection isn’t feasible because there’s no joint yet, pouring during finishing isn’t about forming the structural joint, and removing after erection would leave the joint open rather than creating a continuous wall.