ACI Concrete Strength Testing Technician CP-19 (14) Questions And Answers Latest Top Score.

ACI Concrete Strength Testing Technician CP-19 (14) Questions And Answers Latest Top Score. These procedures for capping enable concrete cylinders and cores to meet the standard's requirements for ________ and _________. - correct answer. Planeness, perpendicularity 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. Glass, metal granite or diabase Sulfur mortar cap plates should be formed against _____ or _____ plates. - correct answer. Metal, Stone The purpose of the guide bar or bull's eye level is to ensure that caps remain perpendicular to the axis of the cylinder within 0.5 degrees. True or False? - correct answer. True To avoid accidents during reheating of cooled sulfur, use melting pots that have _____. - correct answer. Peripheral heating The technician should use a stiff layer of _____ to cap fresh concrete cylinders. - correct answer. Neat cement paste Hardened concrete cylinders should be capped with _____, _____ or _____. - correct answer. High-strength gypsum paste, neat cement paste, or sulfur mortar Plaster of paris and mixtures of plaster of paris and portland cement are examples of suitable high strength plasters. True or False? - correct answer. False Sulfur mortars and high-strength gypsum cement cubes must demonstrate a minimum compressive strength of _____ or ___ __, whichever is greater. - correct answer. 35MPa (5000 psi), the cylinder strength The cement paste should be applied to the freshly molded cylinder from _____ to _____ hours after molding. This is to allow for _____ of the concrete specimen. - correct answer. 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 - correct answer. a, b and d A slight twisting action will help eliminate _____ and air _____ when the capping plate is placed onto the mound of the paste. - correct answer. Excess paste, voids Neat cement paste caps should not be used on dry specimens because the caps may _____ and _____ when dry. - correct answer. Shrink, crack The technician should remove all _____ or _____ materials from the ends of hardened concrete cylinders before capping - correct answer. Oily, waxy _____ the pot and recharge with fresh material at intervals to insure that the oldest material in the pot has not been used more than _____ times. - correct answer. Empty, 5 When capping concrete cylinders with a compressive strength of 35 MPa (5000 psi) or greater, it is permitted to reuse compound recovered from the capping operation of old caps. True or False? - correct answer. False To avoid _____, the sulfur mortar should be dry when it is added to the pot. It should be kept away from _____ when heating. - correct answer. Foaming, water The melting pot for the sulfur mortar must be located under a _____ with an _____ for _____. - correct answer. Hood, exhaust fan, ventillation Hydrogen sulfide gas, which may be produced during capping, may be _____, _____, _____, _____ and _____. - correct answer. Lethal, nausea, stomach distress, dizziness, headache, irritation of the eyes. When qualification tests of unbonded pads are required, they are performed by the _____ or _____. - correct answer. Supplier, user This standard (ASTM 1231) established a maximum number of pad reuses that may not be exceeded under any circumstances. True or false? - correct answer. False Unbonded caps are not to be used for acceptance testing of concrete with compressive strength below _____ or above _____. - correct answer. 1500 psi (10 MPa), 12,000 psi (80 MPa) Polyurethane or butyl pads with a Shore A durometer hardness of 50 that will be used on concrete with a compressive strength of 1500 to 6000 psi (10 to 40 MPa) need not be qualified prior to use. True of False? - correct answer. False To keep track of pad usage, the user is required to maintain records that include_____. - correct answer. Date placed in service, pad durometer, number of uses if a new neoprene pad with a Shore A durometer hardness of 50 is intended to test concrete cylinders with anticipated compressive strengths between 1500 and 6000 psi (10 and 40 MPa), it may be used "as is" from the manufacturer without further qualification testing. True or False? - correct answer. True The term "unbonded cap" refers to the combination of a metal retainer and an elastomeric pad. True or False? - correct answer. True The practice of ASTM C1231 may be used instead of the capping requirements ASTM C617. True or False? - correct answer. True The pads provide a uniform distribution of load from the bearing blocks of the testing machine by deforming in initial loading to conform to the contour of the ends of the cylinder. True or False? - correct answer. True When qualifying unbonded caps, strengths below ____% of the average obtained from bonded caps is considered unacceptable. - correct answer. 98% The practice of ASTM C1231 contains step-by-step procedures for aligning the specimens in the testing machine through complete failure of the cylinder. True or False? - correct answer. False; only through initial application of the load The pads used in this practice (ASTM C1231) must be _____ thick, and the diameter shall not be more than _____ smaller than the inside diameter of the retaining ring. - correct answer. 1/2 ± 1/16 in., 1/16 in. The height of the metal retaining ring must be _____. - correct answer. 1.0 ± 0.1 in.