ACI Strength Exam Study Guide
Questions and Answers19
Name the two allowable materials with with concrete cylinders may be capped with. -
ANSWERS-I. High-strength gypsum
II. Sulfur mortar
III. Neat cement paste
Name the three materials with with cylinders may be capped against. - ANSWERS-I. Glass
II. Metal
III. Granite
Prior to beginning the capping procedure, what must the metal plate be inspected for? -
ANSWERS-I. Grooves
II. Gouches
III. Indentations
What is the maximum allowable size of any indentation on the base plate? - ANSWERS-0.010 in
[0.25 mm]
Upon receipt of the caping material, for how long can it be kept in intervals? - ANSWERS-3
months
When must the neat cement paste be applied it to the cylinder? - ANSWERS-Immediately
,For how long must the concrete settle in the mold prior to applying the neat cement paste? -
ANSWERS-2 to 4 hours
Prior to capping, name the three tasks that must be performed on the cylinder. - ANSWERS-I.
Inspect for any bumps greater than 1/8"
II. Remove foreign debris.
III. Remove any excess water or laitence.
What is the required position of the concrete cylinder? - ANSWERS-90° ± 0.5°
Name the required temperature range of the heated sulfar mortar mixture. - ANSWERS-265°F to
290 °F [130 °C to 145 °C]
What is the maximum number of times that the heated sulfur may be used per cylinder capping
procedure? - ANSWERS-5 times
These procedures for capping enable concrete cylinders and cores to meet the standard
practice's requirements for _____ and _____. - ANSWERS-perpendicularity ... planeness ...
perpendicularity
Equipment needed for the capping process includes capping ____ ____ devices and _____ pots.
- ANSWERS-plates ... alignment ... melting
Plates for neat cement and high-strength gypsum plaster caps should be made of ____, _____,
or _____. - ANSWERS-metal ... glass .... granite
Sulfar mortar cap plates should be formed against _____ or _____ plates. - ANSWERS-marble ...
stone
, True or false? The purpose of the guide bar or bull's eye level is to ensure that caps remain
perpendicular to the axi of the cylinder within 0.5 degrees. - ANSWERS-True
To avoid accidents during reheating of cooled sulfur, use melting pots that have _____. -
ANSWERS-Metal covers
The technician should use a stiff layer of _____ to cap fresh concrete cylinders. - ANSWERS-
Burlap
Hardened concrete cylinders should be capped with ________, ______, or _______. -
ANSWERS-cement paste ... gypsum .... mortar sulfur
True or false? Plasters of paris and mixtures of plaster of paris and portland are examples of
suitable high-strength plasters. - ANSWERS-True
Sulfar mortars and high-strength gypsum cement cubes must demonstrate a minimum
compressive strength of _____ or _____, whichever is greater. - ANSWERS-5000 psi
The cement paste should be applied to the freshly molded cylinder from _____ hours after
molding. This is to allow for _____ of the concrete specimen. - ANSWERS-2-4 ... settling
The strength of the paste depends on:
A. The water-cement ratio
B. Time
C. The equipment used
D. Type of cement - ANSWERS-A. The water-cement ratio
A slight twisting action will help eliminate _____ and air _____ when teh capping plate is placed
onto the ound mound of paste. - ANSWERS-cracks ... voids
Questions and Answers19
Name the two allowable materials with with concrete cylinders may be capped with. -
ANSWERS-I. High-strength gypsum
II. Sulfur mortar
III. Neat cement paste
Name the three materials with with cylinders may be capped against. - ANSWERS-I. Glass
II. Metal
III. Granite
Prior to beginning the capping procedure, what must the metal plate be inspected for? -
ANSWERS-I. Grooves
II. Gouches
III. Indentations
What is the maximum allowable size of any indentation on the base plate? - ANSWERS-0.010 in
[0.25 mm]
Upon receipt of the caping material, for how long can it be kept in intervals? - ANSWERS-3
months
When must the neat cement paste be applied it to the cylinder? - ANSWERS-Immediately
,For how long must the concrete settle in the mold prior to applying the neat cement paste? -
ANSWERS-2 to 4 hours
Prior to capping, name the three tasks that must be performed on the cylinder. - ANSWERS-I.
Inspect for any bumps greater than 1/8"
II. Remove foreign debris.
III. Remove any excess water or laitence.
What is the required position of the concrete cylinder? - ANSWERS-90° ± 0.5°
Name the required temperature range of the heated sulfar mortar mixture. - ANSWERS-265°F to
290 °F [130 °C to 145 °C]
What is the maximum number of times that the heated sulfur may be used per cylinder capping
procedure? - ANSWERS-5 times
These procedures for capping enable concrete cylinders and cores to meet the standard
practice's requirements for _____ and _____. - ANSWERS-perpendicularity ... planeness ...
perpendicularity
Equipment needed for the capping process includes capping ____ ____ devices and _____ pots.
- ANSWERS-plates ... alignment ... melting
Plates for neat cement and high-strength gypsum plaster caps should be made of ____, _____,
or _____. - ANSWERS-metal ... glass .... granite
Sulfar mortar cap plates should be formed against _____ or _____ plates. - ANSWERS-marble ...
stone
, True or false? The purpose of the guide bar or bull's eye level is to ensure that caps remain
perpendicular to the axi of the cylinder within 0.5 degrees. - ANSWERS-True
To avoid accidents during reheating of cooled sulfur, use melting pots that have _____. -
ANSWERS-Metal covers
The technician should use a stiff layer of _____ to cap fresh concrete cylinders. - ANSWERS-
Burlap
Hardened concrete cylinders should be capped with ________, ______, or _______. -
ANSWERS-cement paste ... gypsum .... mortar sulfur
True or false? Plasters of paris and mixtures of plaster of paris and portland are examples of
suitable high-strength plasters. - ANSWERS-True
Sulfar mortars and high-strength gypsum cement cubes must demonstrate a minimum
compressive strength of _____ or _____, whichever is greater. - ANSWERS-5000 psi
The cement paste should be applied to the freshly molded cylinder from _____ hours after
molding. This is to allow for _____ of the concrete specimen. - ANSWERS-2-4 ... settling
The strength of the paste depends on:
A. The water-cement ratio
B. Time
C. The equipment used
D. Type of cement - ANSWERS-A. The water-cement ratio
A slight twisting action will help eliminate _____ and air _____ when teh capping plate is placed
onto the ound mound of paste. - ANSWERS-cracks ... voids
