ACI Concrete Field Testing Technician - Grade 1 (18) Exam Questions and Answers 2024 Correctly done

ASTM C1064 - Answer-Standard Test Method For Temperature of Freshly Mixed Hydraulic-Cement Concrete The end of the temperature sensing portion of the temperature measuring device shall be submerged a minimum of ____ into the freshly mixed concrete. - Answer-3 inches [75 mm] C1064, Sec. 8.1 The temperature measuring device shall have a capacity of measuring the temperature of freshly mixed concrete to ± ____ °F (± ____ °C) throughout a range of ____ °F ( ____ °C). - Answer-±1 °F (±0.5 °C) ; 30 to 120 °F (0 to 50 °C) C1064, Sec. 5.2 The temperature measuring device shall be calibrated ____ , or whenever there is a question of ____ . - Answer-annually, accuracy C1064, Sec. 6.1 The temperature of concrete may be measured in a wheelbarrow. True or False - Answer-True The temperature of concrete may be measured in a wall form. True or False - Answer-True C1064, Sec. 7.1 A composite sample of concrete is required even if the only purpose for obtaining the sample is to determine temperature. True or False - Answer-FalseC1064, Sec. 7.2.2 What must be done to the sample container prior to sampling the concrete? - Answer-Dampen with water C1064, Sec. 7.2.1 What must be done to the concrete surrounding the temperature measuring device after the device is submerged in the fresh concrete? - Answer-Close off air voids by gently pressing the concrete around the device C1064, Sec. 8.1 How long must the temperature measuring device remain in the freshly mixed concrete? - Answerminimum of two minutes, maximum of five minutes C1064, Sec. 8.2 After the temperature of the concrete is read, what is then required? - Answer-Reporting of temperature C1064, Sec. 9.1 The temperature of the concrete is reported to the nearest ____ °F - Answer-1 °F (0.5 °C) C1064, Sec. 9.1 According to Test Method C1064, what is one reason to take the temperature of concrete? - AnswerVerify conformance to a specified requirement for temperature of concreteC1064, Sec. 4.1 A maximum temperature of freshly mixed concrete is specified in ASTM C1064. True or False - AnswerFalse The sample of concrete used for temperature determination must be rodded 25 times. True or False - Answer-False C1064, Sec. 7 & 8 ASTM C172 - Answer-Standard Practice for Sampling Freshly Mixed Concrete Sampling by this practice covers procedures for obtaining representative samples, on which tests are to be performed to determine ____ with quality requirements of the specifications under which the concrete is furnished. - Answer-compliance C172, Sec. 1.1 This practice covers sampling from five types of equipment, which are ____, ____, ____, ____, and ____. - Answer-stationary mixers, paving mixers, revolving drum mixers, continuous mixers, and open top mixers C172, Sec. 5.2.1 - 5.2.4 The maximum allowable time between obtaining the first and final portions of a composite sample shall not exceed ____ . - Answer-15 minutes C172, Sec. 4.1 Portions of a composite sample shall be thoroughly remixed before beginning tests on the sample. True or False? - Answer-TrueC172, Sec. 4.1.1 Start tests for slump, temperature, and air content within ____ after obtaining the final portion of the composite sample? - Answer-5 minutes C172, Sec. 4.1.2 The maximum elapsed time allowed between obtaining the final portion of the composite sample and beginning the tests for slump, temperature, and air content is ____ minutes. - Answer-5 minutes C172, Sec. 4.1.2 Start molding specimens for strength tests within ____ after fabricating the composite sample. - Answer- 15 minutes C172, Sec. 4.1.2 The concrete sample must be protected from contamination and ____ . - Answer-rapid evaporation C172, Sec. 4.1.2 The minimum size sample for making strength test specimens is ____ . - Answer-1 ft³ [28 L] C172, Sec. 5.1 When sampling from a stationary mixer, the batch must be sampled at ____ or more regularly spaced intervals during discharge of the middle portion of the batch. - Answer-two C172, Sec. 5.2.1When sampling from a paving mixer, obtain samples from at least ____ different portions of the pile and combine them into one composite sample for test purposes. - Answer-five C172, Sec. 5.2.2 When sampling from a revolving drum truck mixer, concrete must be sampled at a minimum of ____ regularly spaced intervals during discharge of the middle portion of the batch. - Answer-two C172, Sec. 5.2.3 Concrete samples from a truck mixer must be obtained before any water or admixtures are added to the mixer at the job site. True or False - Answer-False C172, Sec. 5.2.3 The composite sample from a truck mixer must be obtained from the ____ portion of the batch. - Answer-middle C172, Sec. 5.2.3 When the concrete contains aggregate larger than that permitted for a particular test method, the sample of concrete must be ____ before making the test. - Answer-wet sieved C172, Sec. 6.1 C172 (Oral Exam) What must occur before a sample of concrete can be taken from a revolving drum mixer? - Answer-All of the water must be added to the mixer C172 (Oral Exam) Describe the different procedures that can be used to collect a sample of concrete from a stationary or revolving drum mixer. - Answer-Repeatedly pass a receptacle through the entire discharge stream, Completely divert the discharge stream into a sample containerC172 (Oral Exam) What are the required steps for collecting a sample of concrete from a stationary or revolving drum mixer? - Answer-Collect two or more portions of concrete, Take the portions at regularly spaced intervals, Take the portions from the middle of the batch C172 (Oral Exam) Describe the procedure for collecting a sample of pavement concrete deposited on grade. - Answer-Discharge the contents of the paving mixer, Obtain samples from at least five different portions of the pile C172 (Oral Exam) What is the minimum size for a sample when strength test specimens are to be molded? - Answer-1 ft³ (28 L) C172 (Oral Exam) What is the maximum allowable time between obtaining the first and final portions of the composite sample? - Answer-15 minutes C172 (Oral Exam) What is required after the concrete sample has been transported to the place where tests are to be performed? - Answer-Combine and remix the sample with a shovel C172 (Oral Exam) What should be done if the concrete contains aggregate larger than is appropriate for the size of the molds or equipment being used? - Answer-wet sieving C172 (Oral Exam) Start the tests for slump, temperature, and air content within how many minutes after obtaining the final portion of the composite sample? - Answer-5 minutes C172 (Oral Exam) Start molding specimens for strength tests within how many minutes after fabricating the composite sample? - Answer-15 minutes C172 (Oral Exam) From what must the concrete sample be protected? - Answer-Sun, wind, and rapid evaporation ; contamination ASTM C143 - Answer-Standard Test Method for Slump of Hydraulic-Cement Concrete The slump test is applicable to ____ concrete with a maximum size aggregate of ____ . - Answer-plastic , 1½ inch (37.5 mm)C143, Sec. 4.2 When the concrete contains aggregate larger than allowed for the slump test, the large aggregate must be ____ . - Answer-removed by wet sieving the sample over 1½ inch [37.5 mm] sieve C143, Sec. 4.2 The mold for making the slump test is in the shape of _____. - Answer-the frustum of a cone C143, Sec. 3.1 The height of the slump mold is ____ . - Answer-12 inches [300 mm] C143, Sec. 5.1 The interior surface of the slump mold is allowed to have minor irregularities. True or False - AnswerFalse C143, Sec. 5.1 For use in the slump test, the end or both ends of the tamping rod must be ____ . - Answer-rounded to a hemispherical tip C143, Sec. 5.2 The sample of concrete for use in making the slump test must be obtained in accordance with Practice _____. - Answer-C172, Standard Practice for Sampling Freshly Mixed Concrete C143, Sec. 6.1The slump mold should be in a dry condition before beginning the test. True or False - Answer-False; the mold should be dampened. C143, Sec. 7.1 The surface on which the slump mold will be placed must be ____ . - Answer-flat, moist, nonabsorbent, and ridged ; free of vibration C143, Sec. 7.1 The slump mold is filled in _____ layers. - Answer-3 C143, Sec. 7.1 Each layer should fill approximately ____ the volume of the mold. - Answer-1/3 C143, Sec. 7.1 The approximate concrete depth (in vertical distance) after placing the first layer is ____, and the second layer is ____ . - Answer-2⅝ inch [70 mm], 6⅛ inch [160 mm] C143, Sec. 7.1, Note 5 Rod each layer ___ times uniformly over the cross section with the rounded end of the rod. - Answer-25 C143, Sec. 7.2How deep should the tamping rod penetrate into each layer? - Answer-Rod each layer throughout its depth; on the second and final layers, the rod should penetrate into the previous layer approximately 1 inch [25 mm] C143, Sec. 7.2 When rodding the bottom layer, the tamping rod must be ____ to uniformly distribute the strokes. - Answer-slightly inclined C143, Sec. 7.2 What must be done if the concrete drops below the top of the slump mold while the top layer is being rodded? - Answer-Add additional concrete to keep an excess of concrete above the top of the mold at all times C143, Sec. 7.3 Prior to lifting the mold, concrete must be removed from ____ . - Answer-the area surrounding the base of the mold C143, Sec. 7.3 After the final rodding, the sides of the slump mold should be tapped lightly with the tamping rod. True or False - Answer-False C143, Sec. 7.3 When raising the slump mold, it should not be rotated or twisted. True or False - Answer-True C143, Sec. 7.3How much time is allowed for lifting the slump mold? - Answer-5 ±2 seconds C143, Sec. 7.3 The measurement for slump is made from the top of the mold to what point of the concrete specimen? - Answer-The displaced original center of the top surface of the specimen C143, Sec. 7.4 The slump of the concrete is measured and reported to the nearest ____ . - Answer-¼ inch [5 mm] C143, Sec. 8.1 How much time is allowed to conduct the slump test from beginning to completion? - Answer-2½ minutes C143, Sec. 7.3 ASTM C138 - Answer-Standard Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete The diameter of the tamping rod used in this test method is ____ . - Answer-⅝ inch [16 mm] ±1⁄16 inch [2 mm] C138, Sec. 4.2 What is the required shape of the tamping end of the rod? - Answer-Rounded to a hemispherical tip C138, Sec. 4.2What is the required minimum frequency of the vibrator used in this test method? - Answer-9000 vibrations per minute [150 Hz] C138, Sec. 4.3 The outside diameter or side dimension of the vibrating element must be at least ____ but not greater than ____ . - Answer-0.75 in. [19 mm], 1.50 in. [38 mm] C138, Sec. 4.3 A plastic container can be used for the measure in this method. True or False - Answer-False, measure must be steel or other suitable metal C138, Sec. 4.4 What is the minimum thickness of a metal strike-off plate? - Answer-¼ inch [6 mm] C138, Sec. 4.5 What is the minimum thickness for a glass or acrylic strike-off plate? - Answer-½ inch [12 mm] C138, Sec. 4.5