FINALS LEAK Flashcards
(35 cards)
The Normal Consistency of cement is expressed in terms of:
A) Percentage of water by weight
B) Millimeters of penetration of the needle
C) Grams of water per gram of cement
D) No standard unit, It’s a qualitative measure
A) Percentage of water by weight
In the Normal Consistency test, the Vicat apparatus is used to measure:
A) Temperature changes in the cement paste
B) Density of the cement paste
C) Consistency of the cement paste
D) pH of the cement paste
C) Consistency of the cement paste
What factor primarily influences the setting time of cement?
A) Ambient temperature
B) Relative humidity
C) Cement fineness
D) Water-cement ratio
D) Water-cement ratio
The final setting time of cement is the time elapsed between:
A) The beginning of mixing and the point at which the needle fails to penetrate the paste to a specified depth
B) The addition of water to cement and the creation of bleeding in the concrete mixture
C) The creation of bleeding in the concrete mixture and the point at which the needle fails to penetrate the paste.
D) The beginning of hydration and the point at which the paste achieves its maximum compressive strength
A) The beginning of mixing and the point at which the needle fails to penetrate the paste to a specified depth
What is the significance of measuring both the initial and final setting times of cement?
A) To ensure the safety of construction workers
B) To assess the workability of fresh concrete
C) To determine the optimal curing time for concrete
D) To understand the setting characteristics and behavior of cement paste
D) To understand the setting characteristics and behavior of cement paste
During the setting time test, the Vicat apparatus measures the resistance of cement paste to penetration under:
A) Constant temperature
B) Constant pressure
C) Constant humidity
D) Constant volume
A) Constant temperature
B) Constant pressure
What is the effect of moisture on the specific gravity of cement?
A) Moisture decreases the specific gravity of cement.
B) Moisture increases the specific gravity of cement
C) Moisture has no significant effect on the specific gravity of cement
D) The effect of moisture depends on the type of cement
A) Moisture decreases the specific gravity of cement.
During the specific gravity test, the cement sample is typically:
A) Heated to a specific temperature
B) Immersed in water for a specified period
C) Compacted a specified mold
D) Exposed to UV
B) Immersed in water for a specified period
How does the absorption capacity of coarse aggregates affect concrete mixtures?
A) Higher absorption leads to increased workability
B) Lower absorption results in higher concrete strength
C) Absorption affects the water-cement ratio and workability of concrete
D) Absorption has no significant impact on concrete properties
C) Absorption affects the water-cement ratio and workability of concrete
During the moisture content test, the aggregate samples are typically:
A) Immersed in water for a specified period
B) Dried in an oven to remove moisture
C) Compacted into a specified mold
D) Exposed to UV light
B) Dried in an oven to remove moisture
The moisture content of aggregates can be used to estimate their:
A) Compressive strength
B) Flexural strength
C) Water requirement for mixing
D) Particle size distribution
C) Water requirement for mixing
What does the slump test measure in concrete?
A) Compressive strength
B) Workability
C) Setting time
D) Specific gravity
B) Workability
What is the purpose of the slump test in concrete experimentation?
A) To measure the compressive strength of concrete
B) To assess the setting time of concrete
C) To evaluate the flow and consistency of concrete
D) To determine the water-cement ratio of concrete
C) To evaluate the flow and consistency of concrete
What factors can affect the slump of concrete?
A) Water-cement ratio
B) Aggregate size and shape
C) Admixtures
D) All of the above
D) All of the above
- Which type of specimens are commonly made and cured for compressive strength testing of concrete?
A) Cylinders
B) Cubes
C) Beams
D) Spheres
A) Cylinders
What is the purpose of curing concrete specimens?
A) To accelerate the hydration process
B) To reduce the compressive strength of concrete
C) To prevent moisture loss and maintain hydration conditions
D) To Increase the workability of concrete
C) To prevent moisture loss and maintain hydration conditions
What is the recommended curing period for concrete specimens before testing?
A) 3 days
B) 7 days
C) 14 days
D) 28 days
D) 28 days
What is the significance of determining the flexural strength of concrete?
A) Тo assess its resistance to weathering
B) To evaluate a resistance to abrasion
C) To ensure structural safety and serviceability
D) To measure its resistance to shrinkage
C) To ensure structural safety and serviceability
What is the recommended curing period for concrete beam specimens before testing?
A) 3 days
B) 7 days
C) 14 days
D) 28 days
D) 28 days
How does the water-cement ratio affect the flexural strength of concrete?
A) Higher water-cement ratios result in higher flexural strength
B) Lower water-cement ratios result in higher flexural strength
C) Water-cement ratio has no significant effect on flexural strength
D) The effect of the water-cement ratio depends on the type of aggregates used
B) Lower water-cement ratios result in higher flexural strength
What precaution should be taken when conducting flexural tests on concrete beam specimens?
A) Testing specimens with visible cracks or defects
B) Using excessive loading rates
C) Testing specimens before the end of the curing period
D) Testing specimens with insufficient compaction
C) Testing specimens before the end of the curing period
How does the size and shape of concrete beam specimens affect the flexural strength?
A) Larger and thicker specimens generally have higher flexural strength
B) Smaller and thinner specimens generally have higher flexural strength
C) Specimen size and shape have no significant effect on flexural strength
D) The effect of size and shape depends on the curing conditions
B) Smaller and thinner specimens generally have higher flexural strength
What is the significance of determining the flexural strength of concrete in construction рrojects?
А) To estimate its thermal conductivity
B) To assess its resistance to chemical attacks
C) To ensure compliance with design requirements and standards
D) To evaluate its resistance to shrinkage cracks
C) To ensure compliance with design requirements and standards
What does the determination of specific gravity and absorption of coarse aggregates measure?
A) The particle size distribution of aggregates
B) The water-cement ratio in concrete mixtures
C) The voids in aggregates
D) The density and porosity of aggregates
D) The density and porosity of aggregates
