Has anyone used Concept to estimate the deflection of a RC flat slab to EU or British Standards? I followed the example in the Bentley Wiki to ACI limits and whilst I understand the the various construction stages and the age of concrete from casting and creep effects I have been puzzled by the predicted deflections.
I think its down to the Alt. Envelope Factor as the deflection I obtained by isolating the self weight of slab and imposed were as follows;
SW of slab only, max deflection = 6.112mm (250mm thk slab)
Imposed 2.5kN/m2, max deflection = 5.349mm
Now I would have expected that with a load that's about 2.5 times smaller than the self weight that I would get a corresponding deflection that's 2.5 times smaller. Is Concept therefore removing a load that would be beneficial in reducing deflections if it was applied as a blanket load? Also this wouldn't apply to the self weight of the slab as its a permanent load?
I look forward to someone shedding some light on this.
