ACI Concrete Strength Testing Technician CP-19 (14)

These procedures for capping enable concrete cylinders and cores to meet the standard's requirements for ________ and _________. - answer-Planeness, perpendicularity Equipment needed for the capping process includes capping _____ , _____devices, and ______ pots. - answer-Plates, alignment, melting Plates for neat cement and high strength gypsum plaster caps should be made of _____, _____, _____ or _____. - answer-Glass, metal granite or diabase Sulfur mortar cap plates should be formed against _____ or _____ plates. - 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? - answer-True To avoid accidents during reheating of cooled sulfur, use melting pots that have _____. - answer-Peripheral heating The technician should use a stiff layer of _____ to cap fresh concrete cylinders. - answer-Neat cement paste Hardened concrete cylinders should be capped with _____, _____ or _____. - 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? - answer-False Sulfur mortars and high-strength gypsum cement cubes must demonstrate a minimum compressive strength of _____ or ___ __, whichever is greater. - 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. - 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 - 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. - answer-Excess paste, voids Neat cement paste caps should not be used on dry specimens because the caps may _____ and _____ when dry. - answer-Shrink, crack The technician should remove all _____ or _____ materials from the ends of hardened concrete cylinders before capping - 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. - 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? - answer-False To av