brabus:

FYI,

Generally, floors are designed to support the weight of the slab (called dead load) and the weight of furnitures, equipments, and the inhabitants (called live load). However, dead load is much greater than the live load on concrete floors. So we should not depend on the live load capacity of a floor slab to support the weight of workers, materials and concrete from the first floor. Otherwise, we will overload the slab and then theres deflection.

So, the normal assumption is that the concrete will reach full strength in a month (28 days). However, the slab can achieve 70 to 75% of 28 day strength (with proper curing method) in seven days during which it may be considered as strong enough to hold its dead load and some live load.

The Recommendation

To shore the formwork, workers, and the poured concrete at the first floor level so that the loads from the first floor to the slab below is equally distributed to safely support the live and dead loads. With that, you can safely commence block works on the upper level few days (3 - 5 days) after pouring the slab and even do more within a short period of time. But there's a caveat, if possible avoid mixing your concrete on the upper slab to avoid deflection. Leave the props for over a month till the slab achieve full strength.

brabus: Hey Sir Fhemmmy, I'm honoured to have you on our thread.

mufutau55: Heh! Oga brabus, how are things going? I hope the rain is not disturbing the decking work?

Hajji Mufutau

brabus: Work moving along quickly getting form in place for first floor slab. Work continues tomorrow. Meanwhile, rebar is being bent for the spiral staircase.