LADOTD PCC Plant Inspection Certification
Exam — 220 Advanced MCQs| QUESTIONS
AND ANSWERS | LATEST UPDATE |
VERIFIED !!
EXAM DESCRIPTION
This exam covers the full scope of the Louisiana Department of Transportation and Development
(LADOTD) Portland Cement Concrete (PCC) Plant Inspection certification examination. Topics
include: Portland cement types and properties; aggregates (fine and coarse) — sampling, testing,
and specifications; water and admixtures; concrete mix design principles; batching plant
operations and equipment; mixing and delivery; fresh concrete testing (slump, air content, unit
weight, temperature); hardened concrete testing (compressive strength, flexural strength); quality
control and quality assurance procedures; LADOTD Standard Specifications for Roads and
Bridges; ACI (American Concrete Institute) standards; ASTM testing procedures relevant to
PCC; plant inspection procedures; documentation and reporting; acceptance and rejection
criteria; pavement construction; precast concrete; and safety at concrete batch plants.
SECTION 1: PORTLAND CEMENT — TYPES AND
PROPERTIES
1. According to ASTM C150, which Portland cement type is classified as "General Purpose"
cement?
A) Type II
B) Type I (correct answer)
C) Type III
D) Type V
Rationale: ASTM C150 Type I Portland cement is the general-purpose cement used for most
concrete construction where special properties are not required. It is the most commonly used
type in highway and bridge construction.
2. ASTM C150 Type III Portland cement is used when:
, A) Sulfate resistance is required
B) High early strength is needed — achieving in 7 days what Type I achieves in 28 days
(correct answer)
C) Low heat of hydration is required
D) Moderate sulfate resistance is needed
Rationale: Type III cement has finer grinding and higher C3S content, producing rapid strength
gain. It is used in cold weather concreting, precast operations, and situations requiring early form
removal or early traffic loading.
3. Which Portland cement type provides the highest resistance to sulfate attack?
A) Type I
B) Type II
C) Type III
D) Type V (correct answer)
Rationale: ASTM C150 Type V has a very low C3A (tricalcium aluminate) content — the
compound most susceptible to sulfate attack. It is used in soils and waters with high sulfate
concentrations, such as in coastal Louisiana environments.
4. The primary chemical compounds in Portland cement clinker that govern strength
development are:
A) CaO and SiO2 only
B) C3S (alite), C2S (belite), C3A (aluminate), and C4AF (ferrite) (correct answer)
C) Gypsum and calcium carbonate
D) Al2O3 and Fe2O3
Rationale: The four primary Bogue compounds — tricalcium silicate (C3S), dicalcium silicate
(C2S), tricalcium aluminate (C3A), and tetracalcium aluminoferrite (C4AF) — determine
strength development rate, heat of hydration, and sulfate resistance of Portland cement.
5. Gypsum is added to Portland cement clinker during grinding to:
A) Increase the cement's strength
B) Regulate the setting time by retarding the hydration of C3A (correct answer)
C) Reduce the heat of hydration
D) Improve workability of the resulting concrete
,Rationale: Without gypsum, C3A would hydrate very rapidly (flash set), making the concrete
unworkable. Gypsum (calcium sulfate) forms ettringite with C3A, slowing hydration and
providing adequate working time.
6. The minimum compressive strength requirement for Portland cement mortar at 28 days under
ASTM C150 for Type I cement is:
A) 3,000 psi
B) 4,000 psi (approximately 27.6 MPa) (correct answer)
C) 5,000 psi
D) 2,500 psi
Rationale: ASTM C150 establishes minimum compressive strength requirements for standard
mortar cubes made with the cement. Type I requires minimum 28-day strength of approximately
4,000 psi — confirming adequate cement quality before use in concrete production.
7. Supplementary cementitious materials (SCMs) that may be used as partial replacements for
Portland cement in LADOTD concrete include:
A) Only fly ash
B) Fly ash (ASTM C618), slag cement (ASTM C989), and silica fume (ASTM C1240)
(correct answer)
C) Only silica fume and slag
D) Only natural pozzolans
Rationale: LADOTD specifications allow SCMs including Class F and Class C fly ash (ASTM
C618), ground granulated blast furnace slag (ASTM C989), and silica fume (ASTM C1240) as
partial cement replacements — improving durability, reducing heat of hydration, and often
reducing cost.
8. Class F fly ash differs from Class C fly ash primarily in that:
A) Class F has higher calcium content and is more pozzolanic
B) Class F has lower calcium content and is primarily pozzolanic — Class C has higher
calcium and exhibits both pozzolanic and cementitious properties (correct answer)
C) Class C is produced from bituminous coal; Class F from lignite
D) There is no significant performance difference
Rationale: Class F fly ash (from bituminous/anthracite coal) has low CaO content and is
primarily pozzolanic — requiring calcium hydroxide from cement hydration to react. Class C fly
, ash (from subbituminous/lignite coal) has higher CaO content and is both pozzolanic and self-
cementing.
9. The loss on ignition (LOI) test for fly ash indicates:
A) The fly ash's sulfate content
B) The amount of unburned carbon in the fly ash — higher LOI indicates more unburned
carbon, which can affect air entrainment (correct answer)
C) The reactive silica content
D) The fly ash's fineness
Rationale: LOI measures unburned carbon in fly ash. High carbon content absorbs air-entraining
admixtures, making air content control difficult. ASTM C618 limits LOI to 6% maximum (Class
F) and 3% maximum for use in air-entrained concrete in LADOTD work.
10. When cement is received at a concrete batch plant, the LADOTD plant inspector should
verify:
A) The cement color and particle size visually
B) The mill certificate (certified test report) showing compliance with ASTM C150,
delivery ticket quantities, and storage silo identification (correct answer)
C) Only the delivery ticket and invoice
D) Only the ASTM C150 type designation on the bag
Rationale: Proper cement receiving requires verification of: the certified mill test report (CMR)
showing conformance with applicable ASTM standards, delivery quantity, silo identification to
prevent contamination, and any required approval documentation in the LADOTD project
records.
SECTION 2: AGGREGATES
11. Fine aggregate for PCC under LADOTD specifications must meet requirements of:
A) ASTM C33 for grading only
B) ASTM C33 — including grading, deleterious substances, soundness, and other quality
requirements (correct answer)
C) Only the fineness modulus requirement
D) AASHTO T27 grading only
Exam — 220 Advanced MCQs| QUESTIONS
AND ANSWERS | LATEST UPDATE |
VERIFIED !!
EXAM DESCRIPTION
This exam covers the full scope of the Louisiana Department of Transportation and Development
(LADOTD) Portland Cement Concrete (PCC) Plant Inspection certification examination. Topics
include: Portland cement types and properties; aggregates (fine and coarse) — sampling, testing,
and specifications; water and admixtures; concrete mix design principles; batching plant
operations and equipment; mixing and delivery; fresh concrete testing (slump, air content, unit
weight, temperature); hardened concrete testing (compressive strength, flexural strength); quality
control and quality assurance procedures; LADOTD Standard Specifications for Roads and
Bridges; ACI (American Concrete Institute) standards; ASTM testing procedures relevant to
PCC; plant inspection procedures; documentation and reporting; acceptance and rejection
criteria; pavement construction; precast concrete; and safety at concrete batch plants.
SECTION 1: PORTLAND CEMENT — TYPES AND
PROPERTIES
1. According to ASTM C150, which Portland cement type is classified as "General Purpose"
cement?
A) Type II
B) Type I (correct answer)
C) Type III
D) Type V
Rationale: ASTM C150 Type I Portland cement is the general-purpose cement used for most
concrete construction where special properties are not required. It is the most commonly used
type in highway and bridge construction.
2. ASTM C150 Type III Portland cement is used when:
, A) Sulfate resistance is required
B) High early strength is needed — achieving in 7 days what Type I achieves in 28 days
(correct answer)
C) Low heat of hydration is required
D) Moderate sulfate resistance is needed
Rationale: Type III cement has finer grinding and higher C3S content, producing rapid strength
gain. It is used in cold weather concreting, precast operations, and situations requiring early form
removal or early traffic loading.
3. Which Portland cement type provides the highest resistance to sulfate attack?
A) Type I
B) Type II
C) Type III
D) Type V (correct answer)
Rationale: ASTM C150 Type V has a very low C3A (tricalcium aluminate) content — the
compound most susceptible to sulfate attack. It is used in soils and waters with high sulfate
concentrations, such as in coastal Louisiana environments.
4. The primary chemical compounds in Portland cement clinker that govern strength
development are:
A) CaO and SiO2 only
B) C3S (alite), C2S (belite), C3A (aluminate), and C4AF (ferrite) (correct answer)
C) Gypsum and calcium carbonate
D) Al2O3 and Fe2O3
Rationale: The four primary Bogue compounds — tricalcium silicate (C3S), dicalcium silicate
(C2S), tricalcium aluminate (C3A), and tetracalcium aluminoferrite (C4AF) — determine
strength development rate, heat of hydration, and sulfate resistance of Portland cement.
5. Gypsum is added to Portland cement clinker during grinding to:
A) Increase the cement's strength
B) Regulate the setting time by retarding the hydration of C3A (correct answer)
C) Reduce the heat of hydration
D) Improve workability of the resulting concrete
,Rationale: Without gypsum, C3A would hydrate very rapidly (flash set), making the concrete
unworkable. Gypsum (calcium sulfate) forms ettringite with C3A, slowing hydration and
providing adequate working time.
6. The minimum compressive strength requirement for Portland cement mortar at 28 days under
ASTM C150 for Type I cement is:
A) 3,000 psi
B) 4,000 psi (approximately 27.6 MPa) (correct answer)
C) 5,000 psi
D) 2,500 psi
Rationale: ASTM C150 establishes minimum compressive strength requirements for standard
mortar cubes made with the cement. Type I requires minimum 28-day strength of approximately
4,000 psi — confirming adequate cement quality before use in concrete production.
7. Supplementary cementitious materials (SCMs) that may be used as partial replacements for
Portland cement in LADOTD concrete include:
A) Only fly ash
B) Fly ash (ASTM C618), slag cement (ASTM C989), and silica fume (ASTM C1240)
(correct answer)
C) Only silica fume and slag
D) Only natural pozzolans
Rationale: LADOTD specifications allow SCMs including Class F and Class C fly ash (ASTM
C618), ground granulated blast furnace slag (ASTM C989), and silica fume (ASTM C1240) as
partial cement replacements — improving durability, reducing heat of hydration, and often
reducing cost.
8. Class F fly ash differs from Class C fly ash primarily in that:
A) Class F has higher calcium content and is more pozzolanic
B) Class F has lower calcium content and is primarily pozzolanic — Class C has higher
calcium and exhibits both pozzolanic and cementitious properties (correct answer)
C) Class C is produced from bituminous coal; Class F from lignite
D) There is no significant performance difference
Rationale: Class F fly ash (from bituminous/anthracite coal) has low CaO content and is
primarily pozzolanic — requiring calcium hydroxide from cement hydration to react. Class C fly
, ash (from subbituminous/lignite coal) has higher CaO content and is both pozzolanic and self-
cementing.
9. The loss on ignition (LOI) test for fly ash indicates:
A) The fly ash's sulfate content
B) The amount of unburned carbon in the fly ash — higher LOI indicates more unburned
carbon, which can affect air entrainment (correct answer)
C) The reactive silica content
D) The fly ash's fineness
Rationale: LOI measures unburned carbon in fly ash. High carbon content absorbs air-entraining
admixtures, making air content control difficult. ASTM C618 limits LOI to 6% maximum (Class
F) and 3% maximum for use in air-entrained concrete in LADOTD work.
10. When cement is received at a concrete batch plant, the LADOTD plant inspector should
verify:
A) The cement color and particle size visually
B) The mill certificate (certified test report) showing compliance with ASTM C150,
delivery ticket quantities, and storage silo identification (correct answer)
C) Only the delivery ticket and invoice
D) Only the ASTM C150 type designation on the bag
Rationale: Proper cement receiving requires verification of: the certified mill test report (CMR)
showing conformance with applicable ASTM standards, delivery quantity, silo identification to
prevent contamination, and any required approval documentation in the LADOTD project
records.
SECTION 2: AGGREGATES
11. Fine aggregate for PCC under LADOTD specifications must meet requirements of:
A) ASTM C33 for grading only
B) ASTM C33 — including grading, deleterious substances, soundness, and other quality
requirements (correct answer)
C) Only the fineness modulus requirement
D) AASHTO T27 grading only
