ACI Concrete- Section 4 Questions and Answers Graded A+

ACI Concrete- Section 4 Questions and Answers Graded A+ The diameter of the tamping rod used in this test method is ________. 16 mm (5/8") + or - 2 mm (1/16") What is the required shape of the tamping end of the rod Rounded to Hemispherical tip What is the required minimum frequency of the vibrator used in this test method? 9000 vibrations per minute (150Hz) The outside diameter or side dimension of the vibrating element must be at least ______ but not greater than _______. 19 mm (3/4"), 38 mm (1-1/2") A plastic container can be used for the measure in this test method. False, measure must be steel or other suitable metal What is the minimum thickness of a metal strike-off plate? 6 mm (1/4") What is the minimum thickness for a glass or acrylic strike-off plate? 12 mm (1/2") What is the specified weight of the mallet used on measures that are 14 L (0.5 cubic feet) or smaller? 600 + or - 200 g (1.25 + or - 0.5 lbs) Measures other than air meter bowls used for this test must conform to Test Method __________. C29/C29M Air meter bowls used for this test must conform to Test Method ________ and calibrated for volume according to Test Method ________. C231/C231M, C29/C29M The concrete sample must be obtained in accordance with what ASTM practice? C172/C172M What method of consolidation must be used when the slump is greater than 3"? Rodding What method must be used when the slump is less than 1"? Vibration If rodding is the method of consolidation being used, the measure must be filled in how many layers? Three For a measure of 14 L (0.5 cubic feet), what is the required number of strokes of the tamping rod for consolidation of each layer? 25 When rodding the middle and the top layers, the tamping rod should penetrate into the layer below approx. __________. 25 mm (1") If the vibration is the method of consolidation, the measure must be filled in ________ approx. equal layers. Two