NRMCA Concrete Technologist Level 2
Certification Exam Questions and Answers| Latest
Update| Pass Guaranteed
.1. Which ASTM specification governs portland cement in the United States?
A. ASTM C150
B. ASTM C618
C. ASTM C33
D. ASTM C494
Answer: A. ASTM C150
Rationale: ASTM C150 is the Standard Specification for Portland Cement and
defines the eight types of portland cement (I, IA, II, IIA, III, IIIA, IV, V) along
with their chemical and physical requirements.
2. Which portland cement type is characterized by high early strength and is
often used when forms must be removed quickly?
A. Type I
B. Type II
C. Type III
D. Type V
Answer: C. Type III
, Rationale: Type III cement is ground finer and has a higher C3S content than
Type I, giving it high early strength, which is useful for fast-track construction
or cold-weather work where rapid strength gain is needed.
3. Type V portland cement is specifically formulated for which condition?
A. Low heat of hydration in mass concrete
B. High resistance to sulfate attack
C. Rapid strength gain
D. Improved workability
Answer: B. High resistance to sulfate attack
Rationale: Type V cement has a low tricalcium aluminate (C3A) content, which
provides high sulfate resistance, making it suitable for concrete exposed to
soils or groundwater with high sulfate concentrations.
4. Fly ash used as a supplementary cementitious material is governed by which
ASTM standard?
A. ASTM C150
B. ASTM C260
C. ASTM C618
D. ASTM C989
Answer: C. ASTM C618
Rationale: ASTM C618 covers fly ash and natural pozzolans for use in concrete,
classifying fly ash into Class F (low calcium, primarily pozzolanic) and Class C
(high calcium, both pozzolanic and self-cementing).
5. Which class of fly ash typically contains higher calcium content and may
exhibit self-cementing properties?
A. Class F
B. Class C
C. Class N
, D. Class S
Answer: B. Class C
Rationale: Class C fly ash, generally derived from lignite or sub-bituminous
coal, has higher calcium oxide content than Class F and can exhibit
cementitious properties in addition to pozzolanic behavior.
6. Ground granulated blast-furnace slag (GGBFS) used in concrete is specified
under which ASTM standard?
A. ASTM C618
B. ASTM C989
C. ASTM C1240
D. ASTM C595
Answer: B. ASTM C989
Rationale: ASTM C989 covers slag cement (GGBFS) for use in concrete and
mortar, including grade classifications (Grade 80, 100, 120) based on the slag
activity index.
7. Silica fume is primarily added to concrete mixtures to achieve which benefit?
A. Reduce cost of the mixture
B. Increase workability without water
C. Significantly reduce permeability and increase strength
D. Accelerate initial set
Answer: C. Significantly reduce permeability and increase strength
Rationale: Silica fume consists of extremely fine, highly reactive particles that
fill voids between cement grains and react pozzolanically, greatly reducing
permeability and enhancing compressive strength, though it typically increases
water demand.
8. What is the primary reason blended hydraulic cements (ASTM C595) or
performance cements (ASTM C1157) are used?
, A. To eliminate the need for aggregates
B. To combine portland cement with SCMs in one product for specific
performance properties
C. To reduce the need for admixtures entirely
D. To replace all mix water
Answer: B. To combine portland cement with SCMs in one product for
specific performance properties
Rationale: Blended and performance cements are manufactured by
intergrinding or blending portland cement clinker with SCMs such as slag or fly
ash, providing specified performance characteristics (e.g., moderate sulfate
resistance, lower heat of hydration) in a single product.
9. Heat of hydration is a primary concern in which type of concrete placement?
A. Thin pavement overlays
B. Mass concrete such as dams or large footings
C. Precast architectural panels
D. Shotcrete repairs
Answer: B. Mass concrete such as dams or large footings
Rationale: In mass concrete placements, the heat generated by cement
hydration can build up faster than it dissipates, causing large temperature
differentials between the core and surface that can induce thermal cracking;
low-heat cements or SCMs are used to mitigate this.
10. Which compound in portland cement is primarily responsible for early
strength development?
A. Tricalcium silicate (C3S)
B. Dicalcium silicate (C2S)
C. Tricalcium aluminate (C3A)
D. Tetracalcium aluminoferrite (C4AF)
Answer: A. Tricalcium silicate (C3S)
Certification Exam Questions and Answers| Latest
Update| Pass Guaranteed
.1. Which ASTM specification governs portland cement in the United States?
A. ASTM C150
B. ASTM C618
C. ASTM C33
D. ASTM C494
Answer: A. ASTM C150
Rationale: ASTM C150 is the Standard Specification for Portland Cement and
defines the eight types of portland cement (I, IA, II, IIA, III, IIIA, IV, V) along
with their chemical and physical requirements.
2. Which portland cement type is characterized by high early strength and is
often used when forms must be removed quickly?
A. Type I
B. Type II
C. Type III
D. Type V
Answer: C. Type III
, Rationale: Type III cement is ground finer and has a higher C3S content than
Type I, giving it high early strength, which is useful for fast-track construction
or cold-weather work where rapid strength gain is needed.
3. Type V portland cement is specifically formulated for which condition?
A. Low heat of hydration in mass concrete
B. High resistance to sulfate attack
C. Rapid strength gain
D. Improved workability
Answer: B. High resistance to sulfate attack
Rationale: Type V cement has a low tricalcium aluminate (C3A) content, which
provides high sulfate resistance, making it suitable for concrete exposed to
soils or groundwater with high sulfate concentrations.
4. Fly ash used as a supplementary cementitious material is governed by which
ASTM standard?
A. ASTM C150
B. ASTM C260
C. ASTM C618
D. ASTM C989
Answer: C. ASTM C618
Rationale: ASTM C618 covers fly ash and natural pozzolans for use in concrete,
classifying fly ash into Class F (low calcium, primarily pozzolanic) and Class C
(high calcium, both pozzolanic and self-cementing).
5. Which class of fly ash typically contains higher calcium content and may
exhibit self-cementing properties?
A. Class F
B. Class C
C. Class N
, D. Class S
Answer: B. Class C
Rationale: Class C fly ash, generally derived from lignite or sub-bituminous
coal, has higher calcium oxide content than Class F and can exhibit
cementitious properties in addition to pozzolanic behavior.
6. Ground granulated blast-furnace slag (GGBFS) used in concrete is specified
under which ASTM standard?
A. ASTM C618
B. ASTM C989
C. ASTM C1240
D. ASTM C595
Answer: B. ASTM C989
Rationale: ASTM C989 covers slag cement (GGBFS) for use in concrete and
mortar, including grade classifications (Grade 80, 100, 120) based on the slag
activity index.
7. Silica fume is primarily added to concrete mixtures to achieve which benefit?
A. Reduce cost of the mixture
B. Increase workability without water
C. Significantly reduce permeability and increase strength
D. Accelerate initial set
Answer: C. Significantly reduce permeability and increase strength
Rationale: Silica fume consists of extremely fine, highly reactive particles that
fill voids between cement grains and react pozzolanically, greatly reducing
permeability and enhancing compressive strength, though it typically increases
water demand.
8. What is the primary reason blended hydraulic cements (ASTM C595) or
performance cements (ASTM C1157) are used?
, A. To eliminate the need for aggregates
B. To combine portland cement with SCMs in one product for specific
performance properties
C. To reduce the need for admixtures entirely
D. To replace all mix water
Answer: B. To combine portland cement with SCMs in one product for
specific performance properties
Rationale: Blended and performance cements are manufactured by
intergrinding or blending portland cement clinker with SCMs such as slag or fly
ash, providing specified performance characteristics (e.g., moderate sulfate
resistance, lower heat of hydration) in a single product.
9. Heat of hydration is a primary concern in which type of concrete placement?
A. Thin pavement overlays
B. Mass concrete such as dams or large footings
C. Precast architectural panels
D. Shotcrete repairs
Answer: B. Mass concrete such as dams or large footings
Rationale: In mass concrete placements, the heat generated by cement
hydration can build up faster than it dissipates, causing large temperature
differentials between the core and surface that can induce thermal cracking;
low-heat cements or SCMs are used to mitigate this.
10. Which compound in portland cement is primarily responsible for early
strength development?
A. Tricalcium silicate (C3S)
B. Dicalcium silicate (C2S)
C. Tricalcium aluminate (C3A)
D. Tetracalcium aluminoferrite (C4AF)
Answer: A. Tricalcium silicate (C3S)
