問題一覧
1
What is the mode of failure for short columns at which the concrete reaches its limit strain EU at precisely the same instant that the tensile steel on the far side of the column reaches yield strain EY?
Balanced condition
2
Given Es= 29,000 Ksi, Econcrete = 6,000 ksi. What is the modular ratio?
4.83
3
What is the max Vs (Shear carried by the stirrups)?
⅔ sqrt f’c
4
What is the distance from the extreme fiber in compression to the centroid of the tension steel area?
Effective depth
5
The maximum useable strain at the extreme concrete compression fiber shall be assumed to be equal to
0.003
6
A buried plate, wall or block attached at some distance from and forming an anchorage for retaining wall
Deadman
7
It is a beam especially provided over an opening for a door, window, etc. to carry the wall over the opening
Lintel beam
8
What will happen to the concrete strength if the water-to-cement-ratio decreases?
Concrete strength increases, porosity decreases, solid-to-space ratio increases
9
What is the property of concrete by which it continues to deform with time under sustained loads at unit stresses within acceptable elastic range?
Creep
10
Honeycomb structures exhibit: I. Small arches with chain particles II. Has a void ratio of 0.91 for a simple cubic packing III. Has a void ratio of 0.35 for pyramidal packing IV. Negative relative densities
I, IV
11
What is the condition where the tension steel strain reaches the yielding strain simultaneously with the concrete reaching the crushing strain, which is usually 0.003?
Balanced strain
12
What is a material that has adhesive and cohesive properties enabling it to bound mineral fragments into a solid mass in the presence of water?
Hydraulic cement
13
What material have adhesive and cohesive properties necessary to bond inert aggregates into a solid mass of adequate strength and durability?
Cementitious materials
14
What is generated when compound in cement react with water to acquire stable low-energy states?
Heat of Hydration
15
What compounds reduce in the interparticle forces that exist between cement grains in the fresh paste; thereby increasing the paste fluidity
Plasticizers
16
In mixes exposed to water, what is the term used to refer to the separation of aggregate from the bitumen due to the faster adsorption of water on the aggregate surface?
Slippage
17
A parameter used for estimating strength of concrete
Water-cement ratio
18
It is the property of fresh concrete which is the ability to flow under momentum transfer or under mechanical stress?
Mobility
19
True or False: As water cement ratio increases, there is progressive weakening due to increase in porosity
True
20
It is a temporary dam-like structure constructed around an excavation to exclude water
Cofferdam
21
Which of the following is NOT a property of hardened hydraulic cement concrete?
Workability
22
Which of the following properties of aggregates has the LEAST influence to the quality of concrete?
Color, texture, and shape of the aggregates
23
Which of the following will minimize the cracking of pavement due to thermal expansion?
Provide expansion joints and sectional pouring of concrete