ACI Strength Exam Study Guide 2023/2024 with Complete Solutions!!Name the two allowable materials with with concrete cylinders may be capped with. - Correct Answer I. High-strength gypsum II. Sulfur mortar III. Neat cement paste Name the three materials with with cylinders may be capped against. - Correct Answer
- Glass
II. Metal III. Granite Prior to beginning the capping procedure, what must the metal plate be inspected for? - Correct Answer I. Grooves II. Gouches III. Indentations What is the maximum allowable size of any indentation on the base plate? - Correct Answer 0.010 in [0.25 mm] Upon receipt of the caping material, for how long can it be kept in intervals? - Correct Answer 3 months When must the neat cement paste be applied it to the cylinder? - Correct Answer Immediately For how long must the concrete settle in the mold prior to applying the neat cement paste? - Correct Answer 2 to 4 hours Prior to capping, name the three tasks that must be performed on the cylinder. - Correct Answer 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? - Correct Answer 90° ± 0.5° Name the required temperature range of the heated sulfar mortar mixture. - Correct Answer 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? - Correct Answer 5 times These procedures for capping enable concrete cylinders and cores to meet the standard practice's requirements for _____ and _____. - Correct Answer perpendicularity ... planeness ... perpendicularity 1 / 2
Equipment needed for the capping process includes capping ____ ____ devices and _____ pots. - Correct Answer plates ... alignment ... melting Plates for neat cement and high-strength gypsum plaster caps should be made of ____, _____, or _____. - Correct Answer metal ... glass .... granite Sulfar mortar cap plates should be formed against _____ or _____ plates. - Correct Answer 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. - Correct Answer True To avoid accidents during reheating of cooled sulfur, use melting pots that have _____.
- Correct Answer Metal covers
- ... settling
The technician should use a stiff layer of _____ to cap fresh concrete cylinders. - Correct Answer Burlap Hardened concrete cylinders should be capped with ________, ______, or _______. - Correct Answer 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. - Correct Answer True Sulfar mortars and high-strength gypsum cement cubes must demonstrate a minimum compressive strength of _____ or _____, whichever is greater. - Correct Answer 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. - Correct Answer 2-
The strength of the paste depends on:
- The water-cement ratio
- Time
- The equipment used
- Type of cement - Correct Answer A. The water-cement ratio
- / 2
A slight twisting action will help eliminate _____ and air _____ when teh capping plate is placed onto the ound mound of paste. - Correct Answer cracks ... voids Neat cement paste caps should not be used on dry specimens because the caps may _____ and _____ when dry. - Correct Answer crack