Q.
Explain using labelled diagram the following types of floors:-
i) Flush Slab
ii) Beam and Slab
iii) Drop Beam Slab
(25 marks, 2011 Q2)
A.
Similar question was asked in 2015 Q2b(ii).
A concrete slab is common structural element of modern buildings. Horizontal slabs of steel reinforced concrete, typically between 4 and 20 inches (100 and 500 millimeters) thick, are most often used to construct floors and ceilings, while thinner slabs are also used for exterior paving. Sometimes these thinner slabs, ranging from 2 inches (51 mm) to 6 inches (150 mm) thick, are called mud slabs, particularly when used under the main floor slabs[1] or in crawl spaces.[2]
In many domestic and industrial buildings a thick concrete slab, supported on foundations or directly on the subsoil, is used to construct the ground floor of a building. These can either be "ground-bearing" or "suspended" slabs. In high rise buildings and skyscrapers, thinner, pre-cast concrete slabs are slung between the steel frames to form the floors and ceilings on each level.
On the technical drawings, reinforced concrete slabs are often abbreviated to "r.c.c.slab" or simply "r.c.".
i) Flush Slab
Similar question was ask in 2015 Q2b(ii).
ii) Beam and Slab (Beam and Block see here)
Similar question was asked in 2012 Q2b(ii)
iii) Drop Beam Slab
Pros
• Flexibility in vertical service distribution, large openings can be accommodated in the slab elements.
• Inherent corrosion protection and fire resistance.
• Simpler reinforcement arrangement.
• Traditional method of construction.
• Simple method of construction not needing specialist capabilities.
• Robust construction.
Cons
• Large openings cannot be accommodated easily on the beam lines.
• Deep beams reduce head room.
• More complex formwork compared to flat slab systems.
Drop beams and slabs (pros and cons). From Strukts. Available at,http://www.strukts.com/2013/01/drop-beams-and-slabs-pros-and-cons_85.html