ACI- Concrete Field-Testing Technician - Grade 1
Q23. Start the tests for slump, temperature, and air content within how many min. after obtaining the final portion of the composite sample?
+ 5min ASTM C172- (Para. 4.1.2)
Q21. What action is required after the individual concrete samples have been transported to the place where test are to be performed?
+ Combine and remix the samples with a shovel. ASTM C172- (Para. 4.1.1)
Q94. After consolidation of the final layer, an excess of concrete _______ above the top of the measure is considered optimum.
3 mm [1⁄8 in. ASTM C138- (Para 6.5) An excess of concrete protruding approximately 3 mm [1⁄8 in.] above the top of the mold is optimum.
Q55. The slump test is applicable to plastic concrete with a maximum size aggregate of (______) , [_______in]
37.5mm, [1 1/2in] ASTM C143-(Para 4.2) The test method is considered applicable to plastic concrete having coarse aggregate up to 11⁄2 in. [37.5 mm] in size.
Q10. No samples shall be taken before_________ or after_________ of the batch has been discharged. A. 10% or after 90% B. 20% or after 90% C. 20% or after 80% D. None of the above
A. 10% or after 90% ASTM C172- Para (5.2.1). NOTE 3—No samples should be taken before 10 % or after 90 % of the batch has been discharged. Due to the difficulty of determining the actual quantity of concrete discharged, the intent is to provide samples that are representative of widely separated portions, but not the beginning and the end of the load.
Q9. In any case, do not obtain samples until: A. All the water and admixtures have been added to the concrete B. 200 revolutions of the drum have been obtained C. ½ of the water has been added D. None of the above
A. All the water and admixtures have been added to the concrete. ASTM C172- Para (5.2.3). In any case do not obtain samples until after all of the water has been added to the mixer.
Q33. Calibrate the temperature measuring device at least ____________, or whenever there is a question of accuracy. A. Annually B. monthly C. weekly D. daily
A. Annually ASTM C1064- (Para 5.1) The accuracy of each temperature measuring device used for determining the temperature of freshly mixed concrete shall be verified annually.
Q32. ASTM C1064 states the container used to measure temperature of concrete must be large enough to provide at least 5 inches of concrete around the sensor. A. True B. False
B. False ASTM C1064- (Para 4.1) The container shall be large enough to provide at least 75. mm [3 in.] of concrete in all directions around the sensor of the temperature measuring device.
Q80. Aplastic container can be used for the measure in this test method. A. True B. False
B. False ASTM C138- (Para 4.3) A cylindrical container made of steel or other suitable metal.
Q58 .The interior surface of the slump mold is allowed to have minor irregularities. A. True B. False
B. False ASTM C143-(Para 5.1) The interior of the mold shall be relatively smooth and free from projections.
Q72. The slump cone should be struck-off with: A. A float or trowel B. A straight edge C. The tamping rod D. Any of the above
C. The tamping rod ASTM C143- (Para 7.3) After the top layer has been rodded, strike off the surface of the concrete by means of a screeding and rolling motion of the tamping rod.
Q25.From what must the concrete sample be protected?
+ Sun, wind, and rapid evaporation + Contamination ASTM C172- (Para 4.1.2)
Q22. What should be done if the concrete contains aggregate larger than is appropriate for the size of the molds or equipment being used?
+ Wet sieving ASTM C172- (Para. 6.1)
Q76- The diameter of the tamping rod used in this test method is____________ .
16 mm [5⁄8 in.] _+ 2 mm [1⁄16 in.] diameter. ASTM C138- (Para 4.2) Tamping Rod—A round, smooth, straight steel rod, with a 16 mm [5⁄8 in.] _+ 2 mm [1⁄16 in.] diameter
Q62. The approximate concrete depth (in vertical distance) after placing the first layer is________ and second layer is__________.
2 5⁄8 in. [70 mm] and second layer is 6 1⁄8 in. [160 mm] ASTM C143- (Para 7.1) NOTE 5—One third of the volume of the slump mold fills it to a depth of 2 5⁄8 in. [70 mm]; two thirds of the volume fill it to a depth of 6 1⁄8 in. [160 mm].
Q91. When rodding the middle and the top layers, the tamping rod should penetrate into the layer below approximately_________ .
25 mm [1 in.] ASTM C138- (Para 6.3) For each upper layer, allow the rod to penetrate through the layer being rodded and into the layer below approximately 25 mm [1 in.].
Q90. For a measure of 14 L [0.5 ft"), what is the required number of strokes of the tamping rod for consolidation of each layer?
25 strokes ASTM C138- (Para 6.3) Rod each layer with 25 strokes of the tamping rod when nominal 14-L [0.5-ft3].
Q83. What's the specified weight of the mallet used on measures that are 14 L [0.5 ft3] or smaller?
600 +_ 200 g [1.25 +_ 0.50 lb.] ASTM C138- (Para 4.6) A mallet (with a rubber or rawhide head) having a mass of 600 +_ 200 g [1.25 +_ 0.50 lb.] for use with measures of 14 L [0.5 ft3] or smaller.
Q34. After the thermometer is placed in the concrete: A. Gently press concrete around the thermometer. B. Cool the surface of concrete with water. C. Tap the side of the container 10-15 times. D. All of the above
A. Gently press concrete around the thermometer. ASTM C1064- (Para 7.1) Close the void left by the placement by gently pressing the concrete around the temperature measuring device at the surface of the concrete to prevent ambient air temperature from affecting the reading.
Q39 The temperature of concrete may be measured in a wheelbarrow. A. True B. False
A. True
Q40. The temperature of concrete may be measured in a wall form. A. True B. False
A. True
Q100. Concrete slump of less than 1 inch should be consolidated using a vibrator. A. True B. False
A. True ASTM C138- (Para 6.1) Consolidate concretes with a slump less than 25 mm [1 in.] by vibration.
Q99.When rodding the second and third layers, the rod should penetrate the preceding layer by about 1 inch. A. True B. False
A. True ASTM C138- (Para 6.3) For each upper layer, allow the rod to penetrate. through the layer being rodded and into the layer below approximately 25 mm [1 in.].
Q46. According to ASTM C143, it is permissible to use a mold, which clamps to a non-absorbent base. A. True B. False
A. True ASTM C143- (Para 5.2) The mold shall be sufficiently rigid to maintain the specified dimensions and tolerances during use, resistant to impact forces and shall be non-absorbent.
Q67.When raising the slump mold, it should not be rotated or twisted. A. True B. False
A. True ASTM C143- (Para 7.3) Raise the mold a distance of 12 in. [300 mm] in 5 _+ 2 s by a steady upward lift with no lateral or torsional motion.
Q50. When filling the slump cone, each layer should be rodded 25 times. A. True B. False
A. True ASTM C143-(Para 7.2) Rod each layer 25 times uniformly over the cross section with the rounded end of the rod.
Q4. If the concrete contains aggregates larger than those that are appropriate for a size of mold or equipment used, the sample should be wet sieved before making the test. A. True B. False
A. True ASTM C172- Para (6.1)
Q3. The composite concrete sample must be protected from sun, wind, contamination and rapid evaporation. A. True B. False
A. True ASTM C172 - Para (4.1.2)
Q7. ASTM Method C172 includes sampling from stationary mixers, paving mixers, truck mixers, agitators, and non-agitating equipment. A. True B. False
A. True ASTM C172- Para (1.1)
Q35. According to ASTM C1064, what is one reason to take the temperature of concrete? A. Verify conformance B. Verify ambient air temperature C. Verify slump d. D. None of the above.
A. Verify conformance. ASTM C1064- (Para 3.1) To verify conformance to a specified requirement for temperature of concrete
Q28. The temperature measuring device shall have a capacity of measuring temperature of freshly mixed concrete throughout a range of __________________ °F (______________°C)
ASTM C1064- (Para 4.2) a range of [30° to 120 °F] (0° to 50 °C)
Q31. The temperature of the concrete is recorded to the nearest __________°F (______°C).
ASTM C1064- (Para 7.2) Read and record the temperature to the nearest 0.5 °C [1 °F].
Q97. Yield Calculations For a design batch of 5.4 m3 [7.0 yd3], the total mass of all materials batched was 12,383 kg [27,300 Ib]. Using the density of the concrete as determined in Question 96, calculate: a) The yield per batch in ft3 b) The yield per batch in yd3 c) The yield in m3 d) The yield per cubic yard in ft3/yd3 e) The relative yield for the batch of concrete
ASTM C138- (Para 7.3) a)- The yield per batch in ft3 = 27,300 Ib/143.8 (Ib/ft3) =189.8 ft3 b) -The yield per batch in yd3 = 27,300 Ib/143.8 x 27 (Ib/ft3) =7.031 yd3 c)- The yield in m3 = M/D= 12,383 kg /2305=5.372 m3 d)- The yield per cubic yard in ft3/yd3 =(Y ft3/yd3) = yield per batch/ design batch =189.8/7=27.114 ft3/yd3 ASTM C138- (Para 7.4) e)- Ry= yield per batch/ Design Yield Ry(yd3) = 7.031 / 7= 1 Ry(m3) = 5.372 / 5.4= 1 Ry(ft3) = 189.8 / 189= 1
Q98. Your air meter has been damaged in transit to the job site. You do, however, possess the theoretical density that was determined in the lab; it is 2425 kg/m? (151.4 Ib/ft3). Using the density calculated in Question 96, calculate the air content of the batch (in percentage)
ASTM C138- (Para 7.6) Air Content= (2425-2305/2425) x 100%= 5% Air Content = (151.4-143.8/151.4) x100= 5%
Q17. What are the required steps for collecting a sample of concrete from a stationary or revolving drum mixer?
ASTM C172- (Para. 5.2.1 and 5.2.3) + Collect two or more portions of concrete. + Take the portions at regularly spaced intervals. + Take the portions from the middle of the batch.
Q16. Describe the different procedures that can be used to collect a sample of concrete from a stationary or revolving drum mixer.
ASTM C172- (Para. 5.2.1 and 5.23) + Repeatedly pass a receptacle through the entire discharge stream. + Completely divert the discharge stream into a sample container.
Q18. Describe the procedure for collecting a sample of pavement concrete deposited on grade.
ASTM C172- (Para. 5.2.2) + Discharge the contents of the paving mixer. + Obtain samples from at least five different portions of the pile.
Q15. What must occur before a sample of concrete can be taken from a revolving drum mixer?
All water and admixtures must be added to the mixer. ASTM C172- Para (5.2.3)
Q12. Sample the concrete from the chute of a truck mixer by: A. Raising chute to stop the flow and scoop concrete from there into the slump cone and cylinder molds B. Passing a receptacle completely through the discharge steam or by completely diverting the discharge into the sample container C. Holding a shovel in the flow and direct half into a bucket D. None of the above
B. Passing a receptacle completely through the discharge steam or by completely diverting the discharge into the sample container. ASTM C172- Para (5.2.3).
Q11. When strength tests are to be made, the minimum size of the composite sample shall be: A. ¼ cubic foot B. 1 cubic foot C. Any convenient size D. 1 Wheelbarrow
B. 1 cubic foot ASTM C172- Para (5.1). Make the samples to be used for strength tests a minimum of 28 L (1 ft3).
Q52. The elapsed time between the start of filling the slump cone and the removal of the cone must be no more than: A. 1 minute B. 2 1/2 minutes C. 5 minutes D. 15 minutes
B. 2 1/2 minutes ASTM C143-(Para 7.3) Complete the entire test from the start of the filling through removal of the mold without interruption and complete it within an elapsed time of 21⁄2 min.
Q6. Sampling should normally be performed, as the concrete is discharged from the mixer. A. True B. False
B. False ASTM C172-Para (5). NOTE 2—Sampling should normally be performed as the concrete is delivered from the mixer. To the conveying vehicle used to transport the concrete to the forms; however, specifications may require other points of sampling, such as the discharge of a concrete pump.
Q42. The sample of concrete used for temperature determination must be rodded 25 times. A. True B. False
B. False A maximum temperature of freshly mixed concrete is NOT specified in Test Method C1064/C1064M
Q29. A composite sample is not needed if only the temperature test is being run. A. True B. False
B. False ASTM C1064- (Para 6.2.2) Except that composite samples are not required if the only purpose for obtaining the sample is to determine temperature.
Q30. The temperature of fresh concrete in a placement must be measured by inserting a thermometer into the top six inches of concrete. A. True B. False
B. False ASTM C1064- (Para 7.1) The end of the temperature sensing portion is submerged a minimum of 75 mm [3 in.] into the freshly mixed concrete.
Q36. It is allowable to remove the temperature measuring devices from the freshly mixed concrete to read the temperature if you cannot see the reading. A. True B. False
B. False ASTM C1064- (Para 7.2) Do not remove the device from the concrete when reading the temperature.
Q26. For concrete with aggregates less than 3 inches, the thermometer must remain in the fresh concrete sample a minimum of 5 minutes or until the temperature reading stabilizes. A. True B. False
B. False ASTM C1064- (Para 7.2) Leave the temperature measuring device in the freshly. mixed concrete for at least 2 min but not more than 5 min
Q43. A maximum temperature of freshly mixed concrete is specified in Test Method C1064/C1064M. A. True B. False
B. False ASTM C1064-(Para 6 and 7)
Q44- The sides of the slump cone should be tapped with the mallet to consolidate the concrete in the mold. A. True B. False
B. False ASTM C143 (Para 7). mallet was used in the Procedure.
Q61. The slump mold should be in a dry condition before beginning the test. A. True B. False
B. False ASTM C143- (Para 7.1) Dampen the mold and place it on a rigid, flat.
Q45. For the slump test, when rodding the second layer and the top layer, the tamping rod should just penetrate into the underlying layer. A. True B. False
B. False ASTM C143- (Para 7.2) For each upper layer, allow the rod to penetrate through the layer being rodded and into the layer below approximately 1 in. [25 mm].
Q66. After the final rodding, the sides of the slump mold should be tapped lightly with the tamping rod. A. True B. False
B. False ASTM C143- (Para 7.3) After the top layer has been rodded, strike off the surface of the concrete by means of a screeding and rolling motion of the tamping rod.
Q49. The slump test may be done on any flat surface. A. True B. False
B. False ASTM C143-(Para 7.1) Dampen the mold and place it on a rigid, flat, level, moist, nonabsorbent surface, free of vibration.
Q48. The filling of the slump cone should be done in three layers of equal height. A. True B. False
B. False ASTM C143-(Para 7.1) Immediately fill the mold in three layers, each approximately one third the volume of the mold.
Q51. The slump cone is filled in three layers of equal volume. A. True B. False
B. False ASTM C143-(Para 7.1) in three layers, each approximately one third the volume of the mold.
Q47. When filling the final layer of the slump cone, never heap the concrete above the top of the mold. A. True B. False
B. False ASTM C143-(Para 7.3) In filling and rodding the top layer, heap the concrete above the mold before rodding is started.
Q5. The composite sample should not be remixed before beginning any tests. A. True B. False
B. False ASTM C172-Para (4.1.1) -The sample shall be combined and remixed with a shovel the minimum amount necessary to ensure uniformity and compliance with the maximum time limits
Q1. Start molding specimens for strength tests within 30 minutes after fabricating the composite sample. A. True B. False
B. False ASTM C172 -Para (4.1.2) - Start molding. specimens for strength tests within 15 min after fabricating the composite sample.
Q2. The maximum allowable time between obtaining the first and last portions of the composite sample may not exceed 5 minutes. A. True B. False
B. False ASTM C172 - Para (4.1)- The elapsed time shall not exceed 15 min. between obtaining the first and final portions of the composite sample.
Q27. The temperature measuring device must be accurate to within 0.1° A. True B. False
B. False ( +__ 0.5 °C) ASTM C1064- (Para 4.2) shall be capable of accurately measuring the temperature of the freshly mixed concrete to +__ 0.5 °C [61 °F]
Q53. The slump should be measured to the nearest A. Tenth of an inch B. Quarter of an inch C. Half of an inch D. 1 inch
B. Quarter of an inch ASTM C143-(Para 8.1) Report the slump in terms of inches [millimetres] to the nearest 1⁄4 in. [5 mm] of subsidence of the specimen during the test.
Q54. The slump cone should be raised carefully, vertically upward, in a steady motion in ________ Seconds. A. 2 to 6 B. 4 to 8 C. 3 to 7 D. 5 to 9
C. 3 to 7 ASTM C143-(Para 7.3) Remove the mold immediately from the concrete by raising it carefully in a vertical direction. Raise the mold a distance of 12 in. [300 mm] in 5 +_ 2 s by a steady upward lift with no lateral or torsional motion.
Q73. The slump cone must be placed: A. Only on the flat base provided by the mold's manufacturer B. On a flat, clean, dry, wooden surface C. On a flat moist, non-absorbent, rigid surface D. On flat, dampened, compacted soil
C. On a flat moist, non-absorbent, rigid surface. ASTM C143- (Para 7.1) place it on a rigid, flat, level, moist, nonabsorbent surface, free of vibration, and that is large enough to contain all of the slumped concrete.
Q70. The dimensions of the slump cone are: A. Top diameter 6 inches, bottom diameter 12 inches, height 12 inches B. Top diameter 4 inches, bottom diameter 8 inches, height 16 inches C. Top diameter 4 inches, bottom diameter 8 inches, height 12 inches D. None of the above
C. Top diameter 4 inches, bottom diameter 8 inches, height 12 inches. ASTM C143- (Para 5.1) The mold shall be in the form of the lateral surface of the frustum of a cone with the base 8 in. [200 mm] in diameter, the top 4 in. [100 mm] in diameter, and the height 12 in. [300 mm].
Q74.In order to determine slump, you should measure the vertical distance from: A. Top of the mold to the highest point of the slumped concrete B. Top of the concrete to the base of the concrete C. Top of the mold to the displaced original center of the top surface D. None of the above
C. Top of the mold to the displaced original center of the top surface. ASTM C143- (Para 7.4) Immediately measure the slump by determining the vertical difference between the top of the mold and the displaced original center of the top surface of the specimen.
Q13. Fresh concrete to be tested at the job site should be sampled from: A. The beginning of mixer discharge B. The last concrete discharged C. Two or more regularly spaced intervals during discharge of the middle portion of the batch D. All of the above
C. Two or more regularly spaced intervals during discharge of the middle portion of the batch ASTM C172- Para (5.2.1).
Q60. The sample of concrete for use in making the slump test must be obtained in accordance with Practice_______.
C172. ASTM C143- (Para 6.1) The sample of concrete from which test specimens are made shall be representative of the entire batch. It shall be obtained in accordance with Practice C172.
Q86. The concrete sample must be obtained in accordance with what ASTM Practice?
C172/C172M ASTM C138- (Para 5.1) Obtain the sample of freshly mixed concrete in accordance. with Practice C172/C172M.
Q84. Measures other than air meter bowls used for this test must conform to Test Method_________.
C29/C29M ASTM C138- (Para 4.4) All measures, except for measuring bowls of air meters which are also used for Test Method C138/C138M tests, shall conform to the requirements of Test Method C29/C29M.
Q14. The elapsed time between obtaining the first and final portions of the composite sample, according to ASTM C172, shall not exceed: A. 10 minutes B. 20 minutes C. 30 minutes D. None of the above
D. None of the above ASTM C172- Para (4.1) The elapsed time shall not exceed 15 min. between obtaining the first and final portions of the composite sample.
Q8. After sampling is completed, start the tests for slump and air content within: A. 2 ½ minutes B. 10 minutes C. 15 minutes D. None of the above
D. None of the above ASTM C172- Para (4.1.2) Start tests for slump, temperature, and air content within 5 min after obtaining the final portion of the composite sample.
Q96. (Unit Weight) Calculation Known: Volume of measure = 14.27 L or 0.01427 m3 [0.504 ft3] Mass of empty measure = 8.89 kg [19.6 Ib] The procedures of Test Method C138/C138M are followed, and the mass of the measure plus the concrete is found to be 41.78 kg [92.1 1b]. Calculate the density of the concrete in kg/m3 [Ib/ft3]?
Density of the concrete D=(92.1-19.6)/0.504 = 143.84 Ib/ft3 Density of the concrete D=(41.78-8.89)/0.01427 = 2305 kg/m3
Q56. When the concrete contains aggregate larger than allowed for the slump test, the large aggregate must be__________ .
Removed ASTM C143-(Para 4.2) Removed in accordance with the section. titled "Additional Procedure for Large Maximum Size Aggregate Concrete" in Practice C172
Q87. What method of consolidation must be used when the slump is greater than 75 mm [3 in.]?
Rodding ASTM C138- (Para 6.1) Rod concretes with a slump greater than 75 mm [3 in.].
Q85. Air meter bowls used for this test must conform to Test Method_______ and be calibrated for volume according to Test Method_______ .
Test Method C231/C231M, Test Method C29/C29M. ASTM C138- (Para 4.4) When measuring bowls of air meters are used, they shall conform to the requirements of Test Method C231/C231M,and shall be calibrated for volume as described in Test Method C29/C29M.
Q20. What is the maximum allowable time between obtaining the first and final portions of the composite sample?
The maximum allowable time= 15min ASTM C172- (Para. 4.1)
Q19. What is the minimum size for a sample when strength test specimens are to be molded?
The minimum size for a sample is 28 L (1 ft3) ASTM C172- (Para. 5.1)
Q37. The end of the temperature sensing portion of the temperature measuring device is submerged a minimum of ____mm [__in] into the freshly mixed concrete.
a minimum of 75 mm [3 in.] into the freshly mixed concrete. ASTM C1064- (Para 7.1)
Q64. What must be done if the concrete drops below the top of the slump mold while the top layer is being rodded?
add additional concrete to keep an excess of concrete above the top of the mold at all times. ASTM C143- (Para 7.3) If the rodding operation results in subsidence of the concrete below the top edge of the mold, add additional concrete to keep an excess of concrete above the top of the mold at all times.
Q82. What is the minimum thickness for a glass or acrylic strike-off plate?
at least 12 mm [1⁄2 in.] thick ASTM C138- (Para 4.5) glass or acrylic plate at least 12 mm [1⁄2in.] thick.
Q79. The outside diameter or side dimension of the vibrating element must be at least_______ but not greater than__________ .
at least 19 mm [0.75 in.] and not greater than 38 mm [1.50 in.] ASTM C138- (Para 4.3) The outside diameter or the side dimension of the vibrating element shall be at least 19 mm [0.75 in.] and not greater than 38 mm [1.50 in.].
Q81. What is the minimum thickness of a metal strike-off plate?
at least 6 mm [1⁄4 in.] thick ASTM C138- (Para 4.5) Strike-Off Plate—A flat rectangular metal plate at least 6 mm [1⁄4 in.] thick
Q78. What is the required minimum frequency of the vibrator used in this test method?
at least 9000 vibrations per minute [150 Hz] ASTM C138- (Para 4.3) The vibrator frequency shall be at least 9000 vibrations per minute [150 Hz] while the vibrator is operating in the concrete.
Q95. After completing the strike-off procedure, what must be done before weighing the measure and sample?
clean all excess concrete. ASTM C138- (Para 6.7) After strike-off, clean all excess concrete from the exterior of the measure.
Q41. What must be done to the sample container prior to sampling the concrete?
dampen (with water) ASTM C1064-(Para 6.2.1) Immediately, prior to sampling the freshly mixed. concrete, dampen (with water) the sample container.
Q69. The measurement for slump is made from the top of the mold to what point of the concrete specimen?
displaced original center of the top surface of the specimen. ASTM C143- (Para 7.4) Immediately measure the slump by determining the vertical difference between the top of the mold and the displaced original center of the top surface of the specimen.
Q71. In the slump test, if a decided falling away or shearing off the concrete from one side or portion of the mass occurs upon raising the slump cone, one should: A. Reject the load for lack of uniformity B. Accept the load but warn the plant C. Disregard the test and make a new test when the next load arrives D. Disregard the test and make a new test on another portion of the sample.
disregard the test and make a new test on another portion of the sample. ASTM C143- (Para 7.4) If a decided falling away or shearing off of concrete from one side or portion of the mass occurs (Note 6), disregard the test and make a new test on another portion of the sample.
Q68.How much time is allowed for lifting the slump mold?
in 5 _+ 2 s ASTM C143- (Para 7.3) Raise the mold a distance of 12 in. [300 mm] in 5 _+ 2 s by a steady upward lift with no lateral or torsional motion.
Q93. If, after consolidation of the final layer, the concrete level is 13 mm [1/2 in] above the top of the measure, what should be done?
remove a representative portion of the excess concrete with a trowel or scoop immediately. ASTM C138- (Para 6.5) If the measure contains a great excess of concrete at completion of consolidation, remove a representative portion of the excess concrete with a trowel or scoop immediately following completion of consolidation and before the measure is struck-off.
Q65. Prior to lifting the mold, concrete must be removed from__________.
remove concrete from the area surrounding the base of the mold. ASTM C143- (Para 7.3) Remove concrete from the area surrounding the base of the mold to preclude interference with the movement of slumping concrete.
Q77. What's the required shape of the tamping end of the rod?
rounded to a hemispherical tip. ASTM C138- (Para 4.2) The rod shall have the tamping end or both ends rounded to a hemispherical tip of the same diameter as the rod.
Q59. For use in the slump test, the tamping end or both ends of the tamping rod must be ____________ .
rounded to a hemispherical tip. ASTM C143-(Para 5.2) The rod shall have the tamping end or both ends rounded to a hemispherical tip of the same diameter as the rod.
Q63. When rodding the bottom layer, the tamping rod must be __________ to uniformly distribute the strokes.
slightly inclined ASTM C143- (Para 7.2) For the bottom layer, this will necessitate inclining the rod slightly and making approximately half of the strokes near the perimeter.
Q57.The mold for making the slump test is in the shape of___________
the frustum of a cone. ASTM C143-(Para 5.1) The mold shall be in the form of the lateral surface of the frustum of a cone.
Q89. If rodding is the method of consolidation being used, the measure must be filled in how many layers?
three layers ASTM C138- (Para 6.3) Rodding—Place the concrete in the measure in three layers of approximately equal volume.
Q92. If vibration is the method of consolidation, the measure must be filed in ______ approximately equal layers.
two ASTM C138- (Para 6.4) Fill and vibrate the measure in two approximately equal layers.
Q38. The temperature measuring device shall be verified _______or whenever there is a question of_______
verified annually, or whenever there is a question of accuracy. ASTM C1064-(Para5.1)
Q88. What method of consolidation must be used when the slump is less than 25 mm [1 in.]?
vibration ASTM C138- (Para 6.1) Consolidate concretes with a slump less than 25 mm [1 in.] by vibration.
Q24. Start molding specimens for strength tests within how many min. after fabricating the composite sample?
within 15 min ASTM C172- (Para. 4.1.2)
Q75- How much time is allowed to conduct the slump test from beginning to completion?
within an elapsed time of 21⁄2 min. ASTM C143- (Para 7.4) Complete the entire test from the start of the filling through removal of the mold without interruption and complete it within an elapsed time of 21⁄2 min.
