NRMCA CONCRETE TECHNOLOGIST LEVEL 2 EXAM PREP: 200
COMPREHENSIVE QUESTIONS WITH DETAILED ANSWERS AND
RATIONALES
1. Which type of Portland cement is most commonly used for general-
purpose concrete construction where special properties are not
required?
A. Type II
B. Type I
C. Type III
D. Type V
Rationale: Type I cement is the general-purpose cement suitable for all
uses where the special properties of other types are not required.
2. What is the primary purpose of a water-reducing admixture (Type
A) in a concrete mixture?
A. To accelerate the setting time
B. To entrain air for freeze-thaw resistance
C. To reduce the water content while maintaining workability
D. To increase the heat of hydration
Rationale: Water-reducing admixtures allow for a reduction in mixing
water while maintaining the same slump, which typically increases
strength and durability.
3. The fineness modulus (FM) of fine aggregate is a measure of:
A. The average particle size and gradation
,B. The specific gravity of the particles
C. The percentage of voids in the aggregate
D. The absorption capacity of the aggregate
Rationale: The fineness modulus is an empirical factor obtained by
adding the cumulative percentages retained on a specified series of
sieves and dividing by 100, indicating the average particle size.
4. Which of the following is the primary benefit of using Class F fly ash
in a concrete mixture?
A. It significantly increases early-age strength
B. It acts as a pozzolan, reacting with calcium hydroxide to form
additional cementitious compounds
C. It reduces the required air content
D. It accelerates the setting time in cold weather
Rationale: Class F fly ash is a low-calcium pozzolan that reacts with the
calcium hydroxide produced during cement hydration, improving long-
term strength and durability.
5. What does the term "saturated surface-dry" (SSD) mean when
referring to aggregate?
A. The aggregate is completely dry inside and out
B. The internal pores are filled with water, but the external surface is
dry
C. The aggregate is submerged in water
D. The aggregate has a visible film of surface moisture
Rationale: SSD is the condition where the aggregate has absorbed all
the water it can, but there is no free moisture on the surface. This is the
reference state for calculating effective mixing water.
,6. Which test method is used to determine the slump of fresh
concrete?
A. ASTM C39
B. ASTM C143
C. ASTM C231
D. ASTM C138
Rationale: ASTM C143 is the standard test method for slump of
hydraulic-cement concrete, which measures consistency and
workability.
7. The nominal maximum size of coarse aggregate is defined as:
A. The largest sieve on which any aggregate is retained
B. The smallest sieve through which all of the aggregate passes
C. The average size of the aggregate particles
D. The sieve size that retains 50% of the aggregate
Rationale: The nominal maximum size is the smallest sieve opening
through which the entire amount of aggregate is required to pass.
8. Which of the following is NOT a method for determining the air
content of fresh concrete?
A. Pressure method (ASTM C231)
B. Volumetric method (ASTM C173)
C. Compressive strength method (ASTM C39)
D. Gravimetric method (ASTM C138)
Rationale: The compressive strength test (ASTM C39) is performed on
hardened concrete cylinders to determine strength, not the air content
of fresh concrete.
9. What is the primary mechanism by which air entrainment improves
the durability of concrete?
, A. It increases the compressive strength of the concrete
B. It provides microscopic voids that relieve pressure from freezing
water
C. It reduces the permeability of the concrete
D. It accelerates the hydration process
Rationale: Entrained air creates a system of tiny, closely spaced bubbles
that provide space for water to expand as it freezes, preventing internal
cracking.
10. According to ACI 211.1, which of the following is the first step in
the absolute volume method of mix design?
A. Calculating the cement content
B. Estimating the coarse aggregate content
C. Selecting the slump
D. Determining the water-cement ratio
Rationale: The first step in the ACI 211.1 mix design procedure is to
select the slump based on the type of construction and placing method.
11. Which of the following aggregates is most likely to be prone to
Alkali-Silica Reaction (ASR)?
A. Limestone
B. Opal, chert, and volcanic glass
C. Granite
D. Quartz sand
Rationale: Reactive forms of silica, such as opal, chert, and volcanic
glass, can react with alkalis in cement to form an expansive gel that
causes cracking.
12. The water-cementitious materials ratio (w/cm) is calculated by
dividing the weight of water by the weight of:
COMPREHENSIVE QUESTIONS WITH DETAILED ANSWERS AND
RATIONALES
1. Which type of Portland cement is most commonly used for general-
purpose concrete construction where special properties are not
required?
A. Type II
B. Type I
C. Type III
D. Type V
Rationale: Type I cement is the general-purpose cement suitable for all
uses where the special properties of other types are not required.
2. What is the primary purpose of a water-reducing admixture (Type
A) in a concrete mixture?
A. To accelerate the setting time
B. To entrain air for freeze-thaw resistance
C. To reduce the water content while maintaining workability
D. To increase the heat of hydration
Rationale: Water-reducing admixtures allow for a reduction in mixing
water while maintaining the same slump, which typically increases
strength and durability.
3. The fineness modulus (FM) of fine aggregate is a measure of:
A. The average particle size and gradation
,B. The specific gravity of the particles
C. The percentage of voids in the aggregate
D. The absorption capacity of the aggregate
Rationale: The fineness modulus is an empirical factor obtained by
adding the cumulative percentages retained on a specified series of
sieves and dividing by 100, indicating the average particle size.
4. Which of the following is the primary benefit of using Class F fly ash
in a concrete mixture?
A. It significantly increases early-age strength
B. It acts as a pozzolan, reacting with calcium hydroxide to form
additional cementitious compounds
C. It reduces the required air content
D. It accelerates the setting time in cold weather
Rationale: Class F fly ash is a low-calcium pozzolan that reacts with the
calcium hydroxide produced during cement hydration, improving long-
term strength and durability.
5. What does the term "saturated surface-dry" (SSD) mean when
referring to aggregate?
A. The aggregate is completely dry inside and out
B. The internal pores are filled with water, but the external surface is
dry
C. The aggregate is submerged in water
D. The aggregate has a visible film of surface moisture
Rationale: SSD is the condition where the aggregate has absorbed all
the water it can, but there is no free moisture on the surface. This is the
reference state for calculating effective mixing water.
,6. Which test method is used to determine the slump of fresh
concrete?
A. ASTM C39
B. ASTM C143
C. ASTM C231
D. ASTM C138
Rationale: ASTM C143 is the standard test method for slump of
hydraulic-cement concrete, which measures consistency and
workability.
7. The nominal maximum size of coarse aggregate is defined as:
A. The largest sieve on which any aggregate is retained
B. The smallest sieve through which all of the aggregate passes
C. The average size of the aggregate particles
D. The sieve size that retains 50% of the aggregate
Rationale: The nominal maximum size is the smallest sieve opening
through which the entire amount of aggregate is required to pass.
8. Which of the following is NOT a method for determining the air
content of fresh concrete?
A. Pressure method (ASTM C231)
B. Volumetric method (ASTM C173)
C. Compressive strength method (ASTM C39)
D. Gravimetric method (ASTM C138)
Rationale: The compressive strength test (ASTM C39) is performed on
hardened concrete cylinders to determine strength, not the air content
of fresh concrete.
9. What is the primary mechanism by which air entrainment improves
the durability of concrete?
, A. It increases the compressive strength of the concrete
B. It provides microscopic voids that relieve pressure from freezing
water
C. It reduces the permeability of the concrete
D. It accelerates the hydration process
Rationale: Entrained air creates a system of tiny, closely spaced bubbles
that provide space for water to expand as it freezes, preventing internal
cracking.
10. According to ACI 211.1, which of the following is the first step in
the absolute volume method of mix design?
A. Calculating the cement content
B. Estimating the coarse aggregate content
C. Selecting the slump
D. Determining the water-cement ratio
Rationale: The first step in the ACI 211.1 mix design procedure is to
select the slump based on the type of construction and placing method.
11. Which of the following aggregates is most likely to be prone to
Alkali-Silica Reaction (ASR)?
A. Limestone
B. Opal, chert, and volcanic glass
C. Granite
D. Quartz sand
Rationale: Reactive forms of silica, such as opal, chert, and volcanic
glass, can react with alkalis in cement to form an expansive gel that
causes cracking.
12. The water-cementitious materials ratio (w/cm) is calculated by
dividing the weight of water by the weight of:
