Ali Sufyan

Thanks for your response.

Will the form work bear load of 6-ft mass concrete?  It'd be adjusted, ok.

But after removal of form work , will the slab be able to sustain in the air with too much self weight?

Assalam-o-alaikum

I have to design a room(To block Radioactive Rays)  with 6-ft thick concrete walls all around , 6-ft thick concrete base  and 6-ft thick concrete roof slab as well.

Room Size (clear space) is 20' x 20' .

As far as 6-ft walls and base is concerned, it makes some sense but is it possible to pour a concrete roof slab 6ft thick?

There is no issue if you are properly designing a pick-up column i.e, considering the fact that how point load is affecting the shear, flexure and torsion of supporting member.

In concrete compression test, normally 150mmx150mmx150mm concrete cube samples is used for testing. Why isn’t 100mmx100mmx100mm concrete cube samples used in the test instead of 150mmx150mmx150mm concrete cube samples?