SC-3B

Spacing of rebars for slab?

• 200 mm

• 300

• 250

• 100

Answer explanation

Typically for an RC slab, no further than 300mm apart and no closer than what is needed to pour concrete properly ie. greater than 70mm or around that range

Maximum spacing of stirrups on 1/3 of span of beam? (in mm)

• 200

• 600

• 300

• 250

Answer explanation

Spacing between stirrups in beam:- as per general rules and guideline, maximum spacing between stirrups in beam should not be exceed to 300mm or 12″ and minimum should be not less than 100mm or 4″. On general standard spacing of 6″ to 7″ (150 – 180mm) between stirrups provided at middle and 4″ to 5″ (100 – 125mm) at end support of beam.

Standard requirement for steel that is applied in the Philippines.

• ASME

• ASTM

• AISI

• ANSI

What is a structural load carrying masonry?

• RC column

• Shear wall

• Load-bearing CHB

• Steel reinforced concrete

Answer explanation

Concrete Hollow Block (CHB) has two types: load bearing and non-load bearing blocks. Load bearing blocks are those that carry loads aside from its own weight.

Concrete hollow blocks, unless otherwise specified shall be 150mm thick. Load bearing blocks shall have a minimum compressive strength of 750 psi (5.175 mpa) while non-load bearing shall have a minimum compressive strength of 400 psi (2.76 mpa).

What footing is used when column is on the property line?

• continuous footing

• pad footing

• strap footing

• eccentric footing

Answer explanation

Shoe or eccentric footing
Shoe footing is the half cut-out from the original footing and it has a shape of shoe. They are constructed on property boundary, where there is no provision of setback area. It is constructed at the corner of the plot when the exterior column is close to the boundary or property line and hence there is no scope to project footing much beyond the column face.. Column is provided or loaded at the edges of shoe footing.

What footing is used when a wall is load bearing?

• spread footing

• strap footing

• combined footing

• strip footing

Answer explanation

Wall footing or strip footing is a continuous strip of concrete that serves to spread weight of load bearing wall.

What footing is used to transmit heavy loads through steel columns?

• well foundation

• grillage foundation

• isolated foundation

• raft foundation

Answer explanation

Grillage foundation is a special type of isolated footing (spread foundation) generally provided for heavily loaded steel stanchions and used in the location of poor bearing capacity.

The load of the column is distributed or spread to a very large area by means of two or more rolled steel sections (generally I section), each layer laid at the right angle to each other. Both the layers of the joists (not columns) are then embedded in cement concrete.

It is used at the base of the columns. These layers are wrapped in concrete and are at right angles to each other. This type of foundation is generally used for pillars and column scaffolds with a heavy structure.

What footing is used when it is carrying a massive load from the columns and allowable soil pressure is small? 

• strap footing

• pad footing

• pile footing

• raft footing

Answer explanation

Raft Footing
When the column loads are heavy or when the safe bearing capacity of soil is very low, The required footing area become very large. As mentioned this footing is in shallow foundation. So in order to spread the load over large area with less depth then we have to increase the footing area. If we increase footing area the footings are overlapped each other, instead of providing each footing on each column all columns are placed in common footing. A raft foundation is a solid reinforced concrete slab covering entire area beneath the structure and supporting all the columns. Such foundation due to its own rigidity minimizes differential settlements.

What footing is used when the site has slope?

• strap footing

• sloped footing

•  

  pile footing

• stepped footing

Answer explanation

To economize in excavation and foundation walling on sloping sites where the subsoil, such as gravel and sand, is compact it is practice to use a stepped foundation.

Construct a foundation on the slope sites by using stepped Foundation or Stepped Footing

What footing is used when one footing is eccentric and it needs to be connected with adjacent footing?

• Strip footing

• Combined footing

• Strap footing

• Continuous footing