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Arizona CR-9 Concrete Contractor Exam
QUESTIONS AND VERIFIED ANSWERS LATEST
UPDATE THIS YEAR
Arizona CR-9 Concrete Contractor Exam Preparation Guide
Key Knowledge Areas by Category
Estimating / Planning & Specifications (12%)
• Quantity takeoff for concrete volume (cubic yards: L × W × D ÷ 27)
• Waste factor: 5-10% for residential slabs
• Material ordering (aggregate, cement, rebar)
• Reading architectural specifications and site plans
• Project sequencing and critical path
Layout / Excavation (8%)
• Site layout using laser levels, transits
• Soil classification (Type A, B, C) and bearing capacity
• Trenching safety (OSHA 29 CFR 1926.651)
• Frost line depth in Arizona: 0-12 inches
• Compaction requirements for granular base
Formwork (21%)
• Form materials: plywood sheathing for vertical faces
• Form ties and bracing to resist hydrostatic pressure
• Form release agents: oil-based, water-based, silicone-based
• Formwork removal timing (stripping forms)
• Lateral pressure calculation factors: concrete density, form height, slump (NOT ambient
temperature)
Reinforcing Steel (18%)
• Rebar grades: Grade 60 = 60,000 psi yield strength
• Rebar sizes: #3 (3/8"), #4 (1/2"), #5 (5/8"), #6 (3/4")
• Concrete cover requirements: 3" for earth contact, 3/4" for interior non-exposed
• Rebar chairs to maintain cover
• Lap splice lengths: approximately 40 × bar diameter
• Welded Wire Reinforcement (WWR): typical placement 1" from bottom
• Dowels and tie bars
Batching / Mixing (14%)
• Cement types (ASTM C150):
o Type I: general purpose
o Type II: moderate sulfate resistance
o Type III: high early strength
o Type V: high sulfate resistance
• Water-cement ratio: inversely affects strength (lower w/c = higher strength, lower
permeability)
• Slump test (ASTM C143): measures workability
• Air-entraining admixture: freeze-thaw protection (5-8% air content)
• Retarders: slow setting in hot weather
• Superplasticizers: increase workability without adding water
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• Aggregate maximum size: ≤ 1/3 slab thickness
Pour, Place & Cure (19%)
• Maximum drop height to prevent segregation: 8 ft (pump)
• Screeding: initial leveling pass
• Bull float: after screeding, before troweling
• Broom finish: slip-resistant surface for walkways
• Control joints (contraction joints): spacing 24–30 × slab thickness (inches)
• Curing requirements: minimum 7 days (ACI 308)
• Curing methods: plastic sheeting, wet burlap, curing compound
• Hot weather concrete: cool aggregates, add retarders
• Vapor barrier: 6 mil polyethylene minimum under interior slabs
• Exposed aggregate finish: remove top cement paste after curing
Safety (8%)
• OSHA 29 CFR 1926 Subpart P: Excavations (trenching)
• OSHA 29 CFR 1926.651: Protective systems, soil classification
• Fall protection: required at elevations ≥6 ft (OSHA 1926.502)
• Silica dust protection: N-95 respirator (or higher) for concrete cutting
• Guardrail height minimum: 36-42 inches
State-Specific Requirements
• Licensing Agency: Arizona Registrar of Contractors (ROC) under Title 32, Chapter 10
• Surety Bond: Minimum $15,000 for CR-9 license
• Mechanics Lien: File within 120 days of completion; Preliminary 20-Day Notice required to
preserve lien rights
• ADOSH: Arizona Division of Occupational Safety and Health enforces OSHA standards in Arizona
(state-plan state)
Estimating / Planning & Specifications (12% – 30 questions)
1. When performing a quantity takeoff for concrete volume, which unit is most commonly used on
Arizona construction plans?
A) Cubic meters
B) Cubic yards
C) Cubic feet
D) Liters
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Answer: B
Rationale: In the United States, especially in Arizona, concrete quantities are typically expressed in cubic
yards. To calculate, multiply Length × Width × Thickness (in feet) and divide by 27.
2. What is the recommended waste factor for a typical residential concrete slab?
A) 2-3%
B) 5-10%
C) 15-20%
D) 25-30%
Answer: B
Rationale: Residential slabs usually add 5-10% waste to account for spillage, over-fill, and minor errors
during placement.
3. A formwork measures 10 ft long, 4 ft wide, and 0.5 ft deep. What is the total volume of concrete
required?
A) 40 cubic feet
B) 20 cubic feet
C) 10 cubic feet
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D) 5 cubic feet
Answer: B
Rationale: Volume = Length × Width × Depth = 10 ft × 4 ft × 0.5 ft = 20 cubic feet.
4. When converting 12,000 cubic feet of concrete to cubic yards for ordering, what is the correct
conversion?
A) 400 yd³
B) 450 yd³
C) 300 yd³
D) 500 yd³
Answer: B (approximately 444 yd³)
Rationale: 1 cubic yard = 27 cubic feet; 12,000 ÷ 27 = 444.44 yd³. For ordering, round to the nearest
practical order size.
5. Which document provides the dimensional details of a concrete slab, including thickness,
reinforcement, and finish?
A) Project schedule
B) Site plan
Arizona CR-9 Concrete Contractor Exam
QUESTIONS AND VERIFIED ANSWERS LATEST
UPDATE THIS YEAR
Arizona CR-9 Concrete Contractor Exam Preparation Guide
Key Knowledge Areas by Category
Estimating / Planning & Specifications (12%)
• Quantity takeoff for concrete volume (cubic yards: L × W × D ÷ 27)
• Waste factor: 5-10% for residential slabs
• Material ordering (aggregate, cement, rebar)
• Reading architectural specifications and site plans
• Project sequencing and critical path
Layout / Excavation (8%)
• Site layout using laser levels, transits
• Soil classification (Type A, B, C) and bearing capacity
• Trenching safety (OSHA 29 CFR 1926.651)
• Frost line depth in Arizona: 0-12 inches
• Compaction requirements for granular base
Formwork (21%)
• Form materials: plywood sheathing for vertical faces
• Form ties and bracing to resist hydrostatic pressure
• Form release agents: oil-based, water-based, silicone-based
• Formwork removal timing (stripping forms)
• Lateral pressure calculation factors: concrete density, form height, slump (NOT ambient
temperature)
Reinforcing Steel (18%)
• Rebar grades: Grade 60 = 60,000 psi yield strength
• Rebar sizes: #3 (3/8"), #4 (1/2"), #5 (5/8"), #6 (3/4")
• Concrete cover requirements: 3" for earth contact, 3/4" for interior non-exposed
• Rebar chairs to maintain cover
• Lap splice lengths: approximately 40 × bar diameter
• Welded Wire Reinforcement (WWR): typical placement 1" from bottom
• Dowels and tie bars
Batching / Mixing (14%)
• Cement types (ASTM C150):
o Type I: general purpose
o Type II: moderate sulfate resistance
o Type III: high early strength
o Type V: high sulfate resistance
• Water-cement ratio: inversely affects strength (lower w/c = higher strength, lower
permeability)
• Slump test (ASTM C143): measures workability
• Air-entraining admixture: freeze-thaw protection (5-8% air content)
• Retarders: slow setting in hot weather
• Superplasticizers: increase workability without adding water
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• Aggregate maximum size: ≤ 1/3 slab thickness
Pour, Place & Cure (19%)
• Maximum drop height to prevent segregation: 8 ft (pump)
• Screeding: initial leveling pass
• Bull float: after screeding, before troweling
• Broom finish: slip-resistant surface for walkways
• Control joints (contraction joints): spacing 24–30 × slab thickness (inches)
• Curing requirements: minimum 7 days (ACI 308)
• Curing methods: plastic sheeting, wet burlap, curing compound
• Hot weather concrete: cool aggregates, add retarders
• Vapor barrier: 6 mil polyethylene minimum under interior slabs
• Exposed aggregate finish: remove top cement paste after curing
Safety (8%)
• OSHA 29 CFR 1926 Subpart P: Excavations (trenching)
• OSHA 29 CFR 1926.651: Protective systems, soil classification
• Fall protection: required at elevations ≥6 ft (OSHA 1926.502)
• Silica dust protection: N-95 respirator (or higher) for concrete cutting
• Guardrail height minimum: 36-42 inches
State-Specific Requirements
• Licensing Agency: Arizona Registrar of Contractors (ROC) under Title 32, Chapter 10
• Surety Bond: Minimum $15,000 for CR-9 license
• Mechanics Lien: File within 120 days of completion; Preliminary 20-Day Notice required to
preserve lien rights
• ADOSH: Arizona Division of Occupational Safety and Health enforces OSHA standards in Arizona
(state-plan state)
Estimating / Planning & Specifications (12% – 30 questions)
1. When performing a quantity takeoff for concrete volume, which unit is most commonly used on
Arizona construction plans?
A) Cubic meters
B) Cubic yards
C) Cubic feet
D) Liters
, Page 3 of 125
Answer: B
Rationale: In the United States, especially in Arizona, concrete quantities are typically expressed in cubic
yards. To calculate, multiply Length × Width × Thickness (in feet) and divide by 27.
2. What is the recommended waste factor for a typical residential concrete slab?
A) 2-3%
B) 5-10%
C) 15-20%
D) 25-30%
Answer: B
Rationale: Residential slabs usually add 5-10% waste to account for spillage, over-fill, and minor errors
during placement.
3. A formwork measures 10 ft long, 4 ft wide, and 0.5 ft deep. What is the total volume of concrete
required?
A) 40 cubic feet
B) 20 cubic feet
C) 10 cubic feet
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D) 5 cubic feet
Answer: B
Rationale: Volume = Length × Width × Depth = 10 ft × 4 ft × 0.5 ft = 20 cubic feet.
4. When converting 12,000 cubic feet of concrete to cubic yards for ordering, what is the correct
conversion?
A) 400 yd³
B) 450 yd³
C) 300 yd³
D) 500 yd³
Answer: B (approximately 444 yd³)
Rationale: 1 cubic yard = 27 cubic feet; 12,000 ÷ 27 = 444.44 yd³. For ordering, round to the nearest
practical order size.
5. Which document provides the dimensional details of a concrete slab, including thickness,
reinforcement, and finish?
A) Project schedule
B) Site plan
