For a continuous slab of 3 m x 3.5 m size, the minimum overall depth of slab to satisfy vertical deflection limits is
A. 50 mm
B. 75 mm
C. 100 mm
D. 120 mm
Answer: Option B
This Question Belongs to Civil Engineering >> Concrete Technology And Design Of Concrete Structures
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In symmetrically reinforced sections, shrinkage stresses in concrete and steel are respectively
A. Compressive and tensile
B. Tensile and compressive
C. Both compressive
D. Both tensile
Critical section for shear in case of flat slabs is (adopting standard notations)
A. At a distance of effective depth of slab from periphery of column/drop panel
B. At a distance of $$\frac{{\text{d}}}{2}$$ from periphery of column/capital/drop panel
C. At the drop panel of slab
D. At the periphery of column
A. depends on as, only
B. depends on aCbC only
C. depends on both crst and acbc
D. is independant of both ast and acbc where d is the effective depth, ast is per-missible stress in steel in tension and ocbc is permissible stress in concrete in bending compression.
The diameter of ties in a column should be
A. More than or equal to one fourth of diameter of main bar
B. More than or equal to 5 mm
C. More than 5 mm but less than one-fourth of diameter of main bar
D. More than 5 mm and also more than one-fourth of diameter of main bar
Thanks
3m x 3.5m here long/small (3.5/3) is less than 2
Means slab is Two dimensional slab
We know for two dimensional slab
Vertical deflection -
For Simply supported slab = 35
For Continuous Slab = 40
(we design slab for shorter span always)
So for given question
3/depth = 40
So depth = 3000 (in mm)/ 40
Eff. Depth = 75mm
Thanks Mandal
For continuous slab L/d ratio is 40, where L is the smaller dimension of slab.
3000/40=75mm