RC Technology Flashcards
A mixture of water, cement, sand, gravel, or other aggregates.
Concrete
The nominal maximum sizes of coarse aggregates should be greater than ____ the narrowest dimension between sides of forms, ___ the depth of slabs, or ____ the minimum clear spacing between individual reinforcing bars.
1/5, 1/3, 3/4
The shortest length in meters of a commercially available rebar.
6
Aggregates that passes through a No. 4 sieve (about 6mm in size).
Fine Aggregates
The nominal diametre of #8 rebar.
25
It is the 28th day compressive strength of concrete.
fc’
The maximum number or rebar in a bundled bar.
12
The load factor for a dead load as per NSCP 2001.
1.4DL
The load factor for a live load as per NSCP 2001.
1.7LL
The load factor for a wind load as per NSCP 2001.
1.7
A composite member consisting of concrete and reinforcing bars.
Reinforced Concrete
The strength reduction factor for flexure is ____.
0.9
The nominal diametre of #3 rebar in mm.
10mm
The yield strength of grade 40 steel rebar in MPa.
276MPa
The maximum usable strain for concrete is ___.
0.003
Aggregates that are retained through a No. 4 sieve. (about 6mm in size)
Coarse Aggregates
It is the empirical test that measures the workability of fresh concrete.
Slump Test
It is the process in which the concrete is protected from loss of moisture and kept within a reasonable temperature range.
Curing
What is the standard weight in kilograms of one bag Portland Cement?
40 kg
Compute for the modulus of Elasticity in MPa of concrete with fc’ = 21 MPa
21.538 kPa
It is the ratio of weight of water to the weight of cement used in a concrete mix.
Water-Cement Ratio
What is the minimum concrete cover in mm for concrete cast against and permanently exposed to earth.
75 mm
A type of beam with fixed support and a roller support at the other end.
propped beam
A type of admixture that reduces the inter-particle forces that exist between cement grains in the fresh paste; thereby increasing the paste fluidity.
Plasticisers
Which of the following is NOT a property of hardened hydraulic cement concrete?
- Economy
- Durability
- Density
- Workability
Workability
These are referred to as permanent loads or unmovable loads in structures.
Dead Load
As per NSCP 2001, what is the uniform liveload for residential occupancy in kPa?
2 kPa.
True or False: Water coming from clear canals can be mixed in concrete.
False
True or False: Reinforcing Steel is strong in tension.
True
True or False: The higher the water cement ratio, the lower the strength of concrete.
True
True or False: Deformed rebar is better than plain rebar.
True
True or False: Tables and chairs inside a classroom is considered Dead Load.
False
True or False: Live loads for classrooms are larger than that of the libraries.
False
True or False: Elongated gravel is better than rounded gravel.
False
True or False: Under-reinforced design is more preferred by designers other than the over-reinforced design.
True
True or False: A slump of zero mean high workability.
False
True or False: Concrete is strong in compression.
True
True or False: If the water-to-cement ratio decreases, concrete strength increases.
True
True or False: If the water-to-cement ratio decreases, porosity decreases.
True
True or False: If the water-to-cement ratio decreases, solid-to-space ratio increases.
True
True or False: Wind pressure for structures built in Manila is lesser than those in Palawan.
False
True or False: A 3000 psi concrete has a 28th compressive strength equal to 27 MPa.
False
