#1
Which of the following materials is a primary component of concrete?
Cement
ExplanationCement is a primary binding agent in concrete.
#2
What role does water play in the concrete mixture?
To improve workability
ExplanationWater enhances the ease of handling and spreading of concrete.
#3
Which test is used to evaluate the workability of fresh concrete?
Slump test
ExplanationThe Slump test measures the consistency and workability of fresh concrete.
#4
What is the recommended minimum curing period for concrete?
28 days
ExplanationConcrete typically requires at least 28 days of curing for optimal strength development.
#5
Which type of cement is suitable for marine construction?
Sulfate Resistant Cement
ExplanationSulfate Resistant Cement is used in marine environments due to its resistance to sulfate attack.
#6
What is the primary function of curing in concrete?
To prevent rapid moisture loss
ExplanationCuring helps maintain adequate moisture levels in concrete for optimal hydration and strength development.
#7
What is the primary function of coarse aggregate in concrete?
To provide bulk and stability
ExplanationCoarse aggregates contribute to the overall volume and strength of concrete.
#8
Which factor primarily determines the compressive strength of concrete?
Water-cement ratio
ExplanationThe ratio of water to cement significantly impacts concrete strength.
#9
What is the purpose of using admixtures in concrete?
To enhance concrete properties
ExplanationAdmixtures are additives used to improve various characteristics of concrete.
#10
Which type of cement is commonly used for concrete construction in cold weather?
Rapid Hardening Cement (RHC)
ExplanationRapid Hardening Cement is preferred in cold climates for its quick setting properties.
#11
What is the purpose of using reinforcement in reinforced concrete?
To increase tensile strength
ExplanationReinforcement bars are added to concrete to enhance its ability to withstand tensile forces.
#12
Which type of admixture is used to decrease the setting time of concrete?
Accelerating admixture
ExplanationAccelerating admixtures expedite the setting time of concrete.
#13
What is the typical range of slump value for normal concrete?
25-50 mm
ExplanationSlump values between 25-50 mm are common for regular concrete.
#14
What is the primary factor affecting the setting time of concrete?
Ambient temperature
ExplanationTemperature influences the rate at which concrete sets and hardens.
#15
What is the purpose of vibrating concrete during placement?
To compact the concrete
ExplanationVibrating concrete ensures proper compaction, eliminating air voids.
#16
Which test is used to assess the durability of concrete?
Chloride penetration test
ExplanationThe Chloride penetration test evaluates concrete's resistance to chloride ion ingress, a key indicator of durability.
#17
Which factor significantly affects the color of concrete?
Cement type
ExplanationThe type of cement used influences the final color of concrete.