ACI Concrete Strength Testing Technician CP-
19 (14) (Latest 2026/2027 Update) 100%
Verified Actual Exam Questions & Answers |
Grade A
This premium study resource provides 100 verified practice questions and answers for the ACI
Concrete Strength Testing Technician (CP-19) written exam. It is designed to help
professionals master key concepts, boost retention, and pass the closed-book certification
exam on their first attempt.
Why Choose This Study Guide?
• Exam-Focused Prep: Contains 100 targeted multiple-choice questions mirroring the
actual ACI CP-19 exam format.
• Verified Solutions: Every question includes the correct answer
• Time-Saving: Skip dense textbooks and focus on high-yield, tested material.
Core Topics Covered
The practice questions directly align with essential ASTM standards required for certification:
• ASTM C39: Compressive Strength of Cylindrical Concrete Specimens
• ASTM C78: Flexural Strength of Concrete
• ASTM C617: Capping Cylindrical Concrete Specimens
• ASTM C1231: Use of Unbonded Caps for Concrete Cylinders
Key Exam Concepts Reviewed
• Equipment requirements for the capping process (plates, alignment devices, melting
pots).
• Tolerance levels for planeness, perpendicularity, and loading rates.
• Proper safety protocols for handling and reheating sulfur mortar caps.
• Dimensions and specifications for bearing blocks and testing machines.
Target Audience
• Quality control technicians
, • Construction materials testers
• Engineering professionals seeking their ACI Concrete Strength Testing Technician
credential
Q1. What is the purpose of the guide bar or bull's eye level during capping?
[Multiple Choice]
A) To prevent the cap material from cooling too fast
B) To measure the thickness of the cap
C) To keep caps perpendicular to the axis of the cylinder within 0.5 degrees
D) To hold the cylinder in place during curing
Answer: To keep caps perpendicular to the axis of the cylinder within 0.5 degrees
Explanation: The guide bar or bull's eye level is an alignment device used to ensure the cap plate
is perpendicular to the cylinder axis to within 0.5°, which is critical for accurate compressive
testing. Measuring cap thickness, controlling cooling rate, or holding the cylinder are different
functions performed by other tools or procedures and are not the stated purpose of the guide
bar/bull's eye level.
Q2. What special heating feature should melting pots used for reheating cooled
sulfur have to help avoid accidents? [Multiple Choice]
A) Immersion heating
B) Top-down infrared heating
C) Direct flame heating
D) Peripheral heating
Answer: Peripheral heating
Explanation: Peripheral heating distributes heat around the pot to reduce hotspots and minimize
accidental overheating or localized boiling when reheating sulfur. The other heating methods
listed are not the feature the text recommends: top-down infrared, immersion, and direct flame
are not the specified precaution and can increase the risk of uneven heating or hazardous
reactions with sulfur.
Q3. Which factors are listed as affecting the strength of the capping paste?
[Multiple Choice]
A) The aggregate size, mixing speed, and container shape
, B) Only the water-cement ratio and curing temperature
C) The water-cement ratio, time, and the type of cement used
D) The equipment used, ambient humidity, and color of the cement
Answer: The water-cement ratio, time, and the type of cement used
Explanation: Paste strength depends on mixture proportions and curing variables: specifically
the water–cement ratio, the time allowed (curing), and the type of cement. The distractors
include items not specified as determining paste strength in the protocol: equipment used is
explicitly excluded in the source list, and other environmental or procedural factors listed in the
distractors are not the stated determinants.
Q4. What materials are recommended for plates used with neat cement and
high-strength gypsum plaster caps? [Multiple Choice]
A) Wood, plastic, granite, or diabase
B) Glass, ceramic, rubber, or metal
C) Cast iron, plywood, marble, or epoxy
D) Glass, metal, granite, or diabase
Answer: Glass, metal, granite, or diabase
Explanation: Plates that form neat cement or high-strength gypsum plaster caps should be made
of hard, smooth, nonreactive materials to produce a flat, plane surface; glass, metal, granite,
and diabase meet those needs. The distractors mix acceptable and unacceptable materials or
include soft/porous materials (wood, rubber, plywood, epoxy) which would not provide the
required smooth, durable surface for forming caps.
Q5. What minimum compressive strength must sulfur mortars and high-strength
gypsum cement cubes demonstrate? [Multiple Choice]
A) 50 MPa (7250 psi) for all tests
B) 35 MPa (5000 psi) or the cylinder strength, whichever is greater
C) No specified minimum; use manufacturer guidance
D) 25 MPa (3600 psi) or the cylinder strength, whichever is less
Answer: 35 MPa (5000 psi) or the cylinder strength, whichever is greater
Explanation: Caps made from sulfur mortars or high-strength gypsum must themselves be strong
enough to avoid failing before the concrete; the minimum specified is 35 MPa (5000 psi) or the
actual cylinder strength if that is greater. The distractors give incorrect minimums, invert the
, comparison, or claim there is no specified minimum, all of which would allow weak caps and
compromise test validity.
Q6. What is the required practice for recharging the sulfur mortar pot to control
reuse of old material? [Multiple Choice]
A) Mix old and new sulfur to maintain consistent temperature
B) Empty the pot and recharge so the oldest material is not used more than five times
C) Use a continuous feed so material circulates indefinitely
D) Top off the pot daily and never fully empty it
Answer: Empty the pot and recharge so the oldest material is not used more than five
times
Explanation: To avoid degradation from repeated reheating, the pot should be emptied and
replenished so that the oldest material is used at most five times; this limits repeated reheating
cycles. The distractors suggest continual reuse without limits or mixing strategies that do not
control the number of reheating cycles and would risk degraded or unsafe material.
Q7. Against what type of plates should sulfur mortar cap plates be formed?
[Multiple Choice]
A) Wood or plywood boards
B) Metal or stone plates
C) Glass or plastic plates
D) Rubber or neoprene pads
Answer: Metal or stone plates
Explanation: Sulfur mortar is formed hot and requires rigid, nonreactive forming surfaces; metal
or stone plates are specified. Glass or plastic could crack or deform with heat, rubber/neoprene
are elastic pads not used for forming sulfur caps, and wood/plywood would char or deform and
are unsuitable for molding molten materials.
Q8. Look at the diagram. Which component in the unbonded cap assembly
deforms during initial loading to conform to the cylinder end, and why is that
deformation important for achieving a uniform load from the testing machine?
[Short Answer]
Answer: The elastomeric pad deforms. As part of the unbonded cap (pad plus metal
retainer), the pad conforms to the contour of the cylinder end during initial loading so
19 (14) (Latest 2026/2027 Update) 100%
Verified Actual Exam Questions & Answers |
Grade A
This premium study resource provides 100 verified practice questions and answers for the ACI
Concrete Strength Testing Technician (CP-19) written exam. It is designed to help
professionals master key concepts, boost retention, and pass the closed-book certification
exam on their first attempt.
Why Choose This Study Guide?
• Exam-Focused Prep: Contains 100 targeted multiple-choice questions mirroring the
actual ACI CP-19 exam format.
• Verified Solutions: Every question includes the correct answer
• Time-Saving: Skip dense textbooks and focus on high-yield, tested material.
Core Topics Covered
The practice questions directly align with essential ASTM standards required for certification:
• ASTM C39: Compressive Strength of Cylindrical Concrete Specimens
• ASTM C78: Flexural Strength of Concrete
• ASTM C617: Capping Cylindrical Concrete Specimens
• ASTM C1231: Use of Unbonded Caps for Concrete Cylinders
Key Exam Concepts Reviewed
• Equipment requirements for the capping process (plates, alignment devices, melting
pots).
• Tolerance levels for planeness, perpendicularity, and loading rates.
• Proper safety protocols for handling and reheating sulfur mortar caps.
• Dimensions and specifications for bearing blocks and testing machines.
Target Audience
• Quality control technicians
, • Construction materials testers
• Engineering professionals seeking their ACI Concrete Strength Testing Technician
credential
Q1. What is the purpose of the guide bar or bull's eye level during capping?
[Multiple Choice]
A) To prevent the cap material from cooling too fast
B) To measure the thickness of the cap
C) To keep caps perpendicular to the axis of the cylinder within 0.5 degrees
D) To hold the cylinder in place during curing
Answer: To keep caps perpendicular to the axis of the cylinder within 0.5 degrees
Explanation: The guide bar or bull's eye level is an alignment device used to ensure the cap plate
is perpendicular to the cylinder axis to within 0.5°, which is critical for accurate compressive
testing. Measuring cap thickness, controlling cooling rate, or holding the cylinder are different
functions performed by other tools or procedures and are not the stated purpose of the guide
bar/bull's eye level.
Q2. What special heating feature should melting pots used for reheating cooled
sulfur have to help avoid accidents? [Multiple Choice]
A) Immersion heating
B) Top-down infrared heating
C) Direct flame heating
D) Peripheral heating
Answer: Peripheral heating
Explanation: Peripheral heating distributes heat around the pot to reduce hotspots and minimize
accidental overheating or localized boiling when reheating sulfur. The other heating methods
listed are not the feature the text recommends: top-down infrared, immersion, and direct flame
are not the specified precaution and can increase the risk of uneven heating or hazardous
reactions with sulfur.
Q3. Which factors are listed as affecting the strength of the capping paste?
[Multiple Choice]
A) The aggregate size, mixing speed, and container shape
, B) Only the water-cement ratio and curing temperature
C) The water-cement ratio, time, and the type of cement used
D) The equipment used, ambient humidity, and color of the cement
Answer: The water-cement ratio, time, and the type of cement used
Explanation: Paste strength depends on mixture proportions and curing variables: specifically
the water–cement ratio, the time allowed (curing), and the type of cement. The distractors
include items not specified as determining paste strength in the protocol: equipment used is
explicitly excluded in the source list, and other environmental or procedural factors listed in the
distractors are not the stated determinants.
Q4. What materials are recommended for plates used with neat cement and
high-strength gypsum plaster caps? [Multiple Choice]
A) Wood, plastic, granite, or diabase
B) Glass, ceramic, rubber, or metal
C) Cast iron, plywood, marble, or epoxy
D) Glass, metal, granite, or diabase
Answer: Glass, metal, granite, or diabase
Explanation: Plates that form neat cement or high-strength gypsum plaster caps should be made
of hard, smooth, nonreactive materials to produce a flat, plane surface; glass, metal, granite,
and diabase meet those needs. The distractors mix acceptable and unacceptable materials or
include soft/porous materials (wood, rubber, plywood, epoxy) which would not provide the
required smooth, durable surface for forming caps.
Q5. What minimum compressive strength must sulfur mortars and high-strength
gypsum cement cubes demonstrate? [Multiple Choice]
A) 50 MPa (7250 psi) for all tests
B) 35 MPa (5000 psi) or the cylinder strength, whichever is greater
C) No specified minimum; use manufacturer guidance
D) 25 MPa (3600 psi) or the cylinder strength, whichever is less
Answer: 35 MPa (5000 psi) or the cylinder strength, whichever is greater
Explanation: Caps made from sulfur mortars or high-strength gypsum must themselves be strong
enough to avoid failing before the concrete; the minimum specified is 35 MPa (5000 psi) or the
actual cylinder strength if that is greater. The distractors give incorrect minimums, invert the
, comparison, or claim there is no specified minimum, all of which would allow weak caps and
compromise test validity.
Q6. What is the required practice for recharging the sulfur mortar pot to control
reuse of old material? [Multiple Choice]
A) Mix old and new sulfur to maintain consistent temperature
B) Empty the pot and recharge so the oldest material is not used more than five times
C) Use a continuous feed so material circulates indefinitely
D) Top off the pot daily and never fully empty it
Answer: Empty the pot and recharge so the oldest material is not used more than five
times
Explanation: To avoid degradation from repeated reheating, the pot should be emptied and
replenished so that the oldest material is used at most five times; this limits repeated reheating
cycles. The distractors suggest continual reuse without limits or mixing strategies that do not
control the number of reheating cycles and would risk degraded or unsafe material.
Q7. Against what type of plates should sulfur mortar cap plates be formed?
[Multiple Choice]
A) Wood or plywood boards
B) Metal or stone plates
C) Glass or plastic plates
D) Rubber or neoprene pads
Answer: Metal or stone plates
Explanation: Sulfur mortar is formed hot and requires rigid, nonreactive forming surfaces; metal
or stone plates are specified. Glass or plastic could crack or deform with heat, rubber/neoprene
are elastic pads not used for forming sulfur caps, and wood/plywood would char or deform and
are unsuitable for molding molten materials.
Q8. Look at the diagram. Which component in the unbonded cap assembly
deforms during initial loading to conform to the cylinder end, and why is that
deformation important for achieving a uniform load from the testing machine?
[Short Answer]
Answer: The elastomeric pad deforms. As part of the unbonded cap (pad plus metal
retainer), the pad conforms to the contour of the cylinder end during initial loading so
