quiz 1 Flashcards
(22 cards)
It causes the stress in the extreme fiber to reach the modulus of rupture
cracking moment
It is the tensile strength of the concrete and an important parameter for evaluating cracking and deflection in beams.
modulus of rupture
Calculate the modulus of rupture for lightweight concrete with a lambda of 0.85 and with a f’c of 19 MPa
2.297 MPa
Compute the B1 value for a normal concrete with f’c = 40 MPa
0.764
The maximum usable strain at extreme concrete compression fiber.
0.003
What is the tensile yield strain of Grade 230 reinforcement bar?
0.0015
What is the minimum concrete cover in millimeter shall be provided for reinforcement of concrete cast against and permanently exposed to earth?
75 mm
The mode of failure for the reinforced concrete beam when the tension yields prior to crushing of the concrete
Ductile Failure
Compure the equivalent area of fictitious concrete for tension controlled beam section ( 320 mm x 400 mm). Use f’c = 40 MPa, fy = 280 MPa, As = 1800 mm^2 and n = 9.
16200 m^2
Compute the minimum required area of longitudinal steel reinforcement for tension controlled beam secton ( 350 mm x 450 mm) in positive bending. Use f’c = 40 MPa, fy = 280 MPa and d = 400 mm
790 mm^2
Water Cement Ratio is
Volume of water to the volume of cement
The lower the cement ratio will lead to ________
high strength
Which compound gives color to the cement?
iron oxide
This is to take into consideration the uncertainties of material strength, approximations in analysis possible variations in dimensions of concrete and placement of concrete. The Code pescribes the value of this as 0.9 for bending reinforce concrete.
strength reduction factor
A process by which concrete is kept moist for its first week or month to provide enough water for the cement to harden. In concrete, it shall be maintained above 10 degrees Celcius and in moist condition for atleast 7 days after placement except when cured by high pressure steam. For high early strength concrete shall be above 10 degrees Celcius and in moist condition for atleast 3 days except when cured by high pressure steam
Curing
Proportion of materials for concrete shall be established to provide
workability and consistency to permit concrete to be worked readily into forms and around the reinforcement
The compressive strength of fully concrete is most directly equal to
water - cement ratio
In the design of reinforced concrete structure, tensile strength of the concrete is normally
neglected
When the area of the concrete structure and the steel are just enough to carry the compression and tension forces simultaneously, the design is
balance design
It consists of monolithic series of members that interact to support loads placed on the structure.
reinforced concrete structures
The design and and construction of buildings is regulated by municipal laws called
Building Codes
The design and and construction of buildings is regulated by municipal laws called
Building Codes
