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Concrete Sampling and Testing Practice Questions, Exams of Construction

200 practice questions and answers related to concrete sampling and testing. The questions cover procedures for obtaining representative samples, equipment types, elapsed time between obtaining samples, temperature reporting, slump test, density, yield, and air content. useful for students studying civil engineering, construction management, or materials science.

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2023/2024

Available from 12/17/2023

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Download Concrete Sampling and Testing Practice Questions and more Exams Construction in PDF only on Docsity! ACI GRADE 1 WRITTEN EXAM LATEST REAL EXAM 200 QUESTIONS AND CORRECT ANSWERS | LATEST VERSION (2024) | GRADED A+ 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 listed under which the concrete is furnished (C172/C172M-17 = Sampling Freshly Mixed Concrete) ----- CORRECT ANSWER--------------Compliance This practice covers sampling from five types of equipment which are... (C172/C172M-17 = Sampling Freshly Mixed Concrete) -----CORRECT ANSWER--------------Stationary, paving, revolving drum, continous, and open top mixers The elapsed time between obtaining the first and final portions of a composite sample shall not exceed... (C172/C172M-17 = Sampling Freshly Mixed Concrete) -----CORRECT ANSWER--------------15 mins T or F: Portions of a composite sample shall be thoroughly remixed before beginning tests on the sample (C172/C172M-17 = Sampling Freshly Mixed Concrete) -----CORRECT ANSWER--------------True Start tests for slump, temperature, and air content within ___ after obtaining the final portion of the composite sample (C172/C172M-17 = Sampling Freshly Mixed Concrete) -----CORRECT ANSWER--------------5 Start molding specific ends for strength tests within ___ after fabricating the composite sample (C172/C172M-17 = Sampling Freshly Mixed Concrete) - ----CORRECT ANSWER--------------15 The concrete sample must be protected from contamination and ... (C172/C172M-17 = Sampling Freshly Mixed Concrete) -----CORRECT ANSWER--------------Rapid evaporation (also sun and wind) The minimum size sample for making strength test specimens is ... (C172/C172M-17 = Sampling Freshly Mixed Concrete) -----CORRECT ANSWER--------------28 L (aka 1 ft3) 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 (C172/C172M-17 = Sampling Freshly Mixed Concrete) ----- CORRECT ANSWER--------------2 When 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 (C172/C172M-17 = Sampling Freshly Mixed Concrete) --- --CORRECT ANSWER--------------5 When sampling from a revolving drum truck mixer, sample the concrete by collecting ___ or more portions take at regularly spaced intervals during discharge of the middle portion of the batch. (C172/C172M-17 = Sampling Freshly Mixed Concrete) -----CORRECT ANSWER--------------2 concrete) -----CORRECT ANSWER--------------At least 2 mins, but not more than 5 minutes After the temperature of the concrete is read, what is then required? (C1064/C1064M-17, Temperature of Freshly Mixed Hydraulic-cement concrete) -----CORRECT ANSWER--------------Reporting of temperature The temperature of the concrete is reported to the nearest... (C1064/C1064M-17, Temperature of Freshly Mixed Hydraulic-cement concrete) -----CORRECT ANSWER--------------0.5 C (1 F) According to Test Method C1064/C1064M, what is one reason to take the temperature of concrete? (C1064/C1064M-17, Temperature of Freshly Mixed Hydraulic-cement concrete) -----CORRECT ANSWER-------------- Verify conformance to a specified requirement for temperature of concretely T or F: A maximum temperature of freshly mixed concrete is specified in ASTM C1064. (C1064/C1064M-17, Temperature of Freshly Mixed Hydraulic-cement concrete) -----CORRECT ANSWER--------------False T or F: The sample of concrete used for temperature determination must be rodded 25 times. (C1064/C1064M-17, Temperature of Freshly Mixed Hydraulic-cement concrete) -----CORRECT ANSWER--------------False (not rodded at all) The slump test is applicable to plastic concrete with a maximum size aggregate of _____. (C143/C143M - 15a, Slump of Hydraulic-Cement Concrete) -----CORRECT ANSWER--------------1.5 in (37.5 mm) When the concrete contains aggregate larger than allowed for the slump test, the large aggregate must be _____. (C143/C143M - 15a, Slump of Hydraulic-Cement Concrete) -----CORRECT ANSWER--------------Removed by wet surfing the sample over 1.5 in (37.5 mm) sieve The mold for making the slump test is in the shape of _____. (C143/C143M - 15a, Slump of Hydraulic-Cement Concrete) -----CORRECT ANSWER------ --------The frustum of a cone The height of the slump mold is _____. (C143/C143M - 15a, Slump of Hydraulic-Cement Concrete) -----CORRECT ANSWER--------------12 in (300 mm) T or F: The interior surface of the slump mold is allowed to have minor irregularities. -----CORRECT ANSWER--------------False For use in the slump test, the tamping end or both ends of the tamping rod must be ___. (C143/C143M - 15a, Slump of Hydraulic-Cement Concrete) -- ---CORRECT ANSWER--------------Rounded to a hemispherical tip The sample of concrete for use in making the slump test must be obtained in accordance with Practice ___. (C143/C143M - 15a, Slump of Hydraulic- Cement Concrete) -----CORRECT ANSWER--------------C172/C172M T or F: The slump mold should be in a dry condition before beginning the test. -----CORRECT ANSWER--------------False The surface on which the slump mold will be placed must be _____. (C143/C143M - 15a, Slump of Hydraulic-Cement Concrete) -----CORRECT ANSWER--------------Flat, moist, nonabsorbent, and rigid The slump mold is filled in ___ layers. (C143/C143M - 15a, Slump of Hydraulic-Cement Concrete) -----CORRECT ANSWER--------------3 Each layer should fill approximately _____ the volume of the mold. (C143/C143M - 15a, Slump of Hydraulic-Cement Concrete) -----CORRECT ANSWER--------------1/3 The approximate concrete depth (in vertical distance) after placing the first layer is ___, and the second layer is ___. (C143/C143M - 15a, Slump of Hydraulic-Cement Concrete) -----CORRECT ANSWER--------------2-5/8 in (70 mm), 6-1/8 in (160 mm) Rod each layer ___ times uniformly over the cross section with the rounded end of the rod. (C143/C143M - 15a, Slump of Hydraulic-Cement Concrete) -----CORRECT ANSWER--------------25 Measures other than air meter bowls used for this test must conform to ASTM _____. (C138/C138M - 17a, Density (unit weight), yields, and air V = 0.01427 m3 Mass of empty = 8.89 kg Mass with sample = 41.78 kg Want D (21) (C138/C138M - 17a, Density (unit weight), yields, and air content (gravimetric) of concrete) -----CORRECT ANSWER--------------2305 kg/m3 (143.8 lb/ft3) Mass with sample: 41.78 kg Minus mass without sample: 8.89 kg Mass of sample: 32.89 kg D= M/V V = 0.01427 m3 Use density from earlier question to solve (C138/C138M - 17a, Density (unit weight), yields, and air content (gravimetric) of concrete) (22) ----- CORRECT ANSWER--------------Yield per batch 189.8 ft3 Y = M/D Want relative yield (C138/C138M - 17a, Density (unit weight), yields, and air content (gravimetric) of concrete) (23) -----CORRECT ANSWER----------- ---1.00 Y/Yd 189.9 ft3/189 ft3 Calc did content from D in earlier question (C138/C138M - 17a, Density (unit weight), yields, and air content (gravimetric) of concrete) (24) ----- CORRECT ANSWER--------------5.0 % (151.4-143.8)/151.4 * 100 = 5.0% The pressure method of determining air content can be used on concrete containing _____ _____ aggregate. (C231/C231M - 17a, air content of freshly mixed concrete by the pressure method) -----CORRECT ANSWER-- ------------Relatively dense The pressure method of determining air content can not be used on concrere containing the following types of aggregate... (C231/C231M - 17a, air content of freshly mixed concrete by the pressure method) ----- CORRECT ANSWER--------------Lightweight, air-cooled blast furnace slag, aggregates of high porosity What is the minimum allowable capacity of the measuring bowl used in the testing method (C231/C231M - 17a, air content of freshly mixed concrete by the pressure method) -----CORRECT ANSWER--------------6.0 L (0.20 ft3) What are the required characteristics of the tamping rod used in the test method (C231/C231M - 17a, air content of freshly mixed concrete by the pressure method) -----CORRECT ANSWER--------------Round, straight steel rod, with a 16 mm (5/8 in) +/- 2 mm (1/16 in) diameter, length of at least 100 mm (4 in) greater than the depth of the measuring bowl, but not greater than 600 mm (24 in) in overall length, with the tamping end or both needs rounded to hemispherical tip of the same diameter as the rod. The sample of concrete used in this test method must be obtained in accordance with what ASTM Standard? (C231/C231M - 17a, air content of freshly mixed concrete by the pressure method) -----CORRECT ANSWER-- ------------C172/C172M The maximum size aggregate allowed for this test method is _____. (C231/C231M - 17a, air content of freshly mixed concrete by the pressure method) -----CORRECT ANSWER--------------50 mm (2 in) If the concrete contains aggregate larger than the maximum allowed for this test, the sample must be _____. (C231/C231M - 17a, air content of freshly mixed concrete by the pressure method) -----CORRECT ANSWER----------- ---Wet sieved over a 37.5 mm (1.5 in) siege If the concrete sample is to be consolidated by rodding, the measure is filled in _____ layers. (C231/C231M - 17a, air content of freshly mixed concrete by the pressure method) -----CORRECT ANSWER--------------3 equal If the concrete sample is to be consolidated by vibration, the measure is filled in _____ layers. (C231/C231M - 17a, air content of freshly mixed concrete by the pressure method) -----CORRECT ANSWER--------------2 equal When rodding the concrete sample, what is the specified number of strokes required for each layer? (C231/C231M - 17a, air content of freshly mixed concrete by the pressure method) -----CORRECT ANSWER--------------25 Vibration of the concrete sample is not allowed when the slump of concrete exceeds _____. (C231/C231M - 17a, air content of freshly mixed concrete by the pressure method) -----CORRECT ANSWER--------------75 mm (3 in) density polyethylene bar or other plastic of equal or greater abrasion resistance, at least 6 by 20 by 300 mm (1/4 by 3/4 by 12 in) What is the approximate volume of the measuring cup used to add water to the air meted, in relation to the volume of the air meter bowl? (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) -- ---CORRECT ANSWER--------------1.00 +/- 0.04 % What type of alcohol and concentration must be used in this test method? (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) -----CORRECT ANSWER--------------Isopropyl, 70% by volume (65% by weight) A mallet weighing ____ must be used to tap the sides of the bowl after rodding each layer. (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) -----CORRECT ANSWER-------------- 600 +/- 200 g (1.25 +/- 0.50 lb) The sample of concrete used in this test method must be obtained in accordance with what ASTM Standard? (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) -----CORRECT ANSWER--------------C172/C172M The maximum size aggregate allowed for this test method is _____. (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) -----CORRECT ANSWER--------------37.5 mm (1.5 in) If the concrete sample contains aggregate larger than that allowed for this test, the sample must be _____. (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) -----CORRECT ANSWER-------- ------Wet sieved over a 25-mm (1-in) sieve When filling the measuring bowl of the air meter, the concrete must be placed in _____ layers of equal volume. (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) -----CORRECT ANSWER--------------2 What is the specific number of strokes required when rodding each layer of concrete? (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) -----CORRECT ANSWER--------------25 T of F: It is necessary to tap the sides of the measuring bowl after each layer has been rodded. (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) -----CORRECT ANSWER-------------- True T or F: The initial quantity of water and alcohol added to the air meter can be poured directly into the neck of the top section of the air meter. (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) -----CORRECT ANSWER--------------False, the funnel must be used Upon final filling of the air meter with water, what part of the liquid level should be adjusted to the zero mark on the meter? (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) ----- CORRECT ANSWER--------------Bottom of the meniscus How long should the air meter be inverted and agitated? (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) ----- CORRECT ANSWER--------------No more than 5 seconds at a time, but must be repressed for a minimum of 45 seconds to free concrete from the base How many times does the rolling operation occur? (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) ----- CORRECT ANSWER--------------A minimum of 2, maximum of 3 Why is the isopropyl alcohol added to the meter? (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) ----- CORRECT ANSWER--------------To dispel any foam that may be on the surface of the water The direct reading of the final liquid level in the neck of the air meter, is estimated to teh nearest _____. (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) -----CORRECT ANSWER-------- ------0.25 % If the air content is greater than the 9% range of the meter, _____. (C173/C173 M - 16, Air Content of Freshly Mixed Concrete by the Volumetric Method) -----CORRECT ANSWER--------------Calibrated cups of water are added to bring the liquid level within the graduates range T or F: In order for an initial meter reading to be valid, the meter must not be leaking, the liquid level must stabilize within 6 minutes, and the foam on the surface of the liquid must not be greater than 2 full percent divisions. Concrete Test Specimens in the Field) -----CORRECT ANSWER-------------- C172/C172M When strength specimens are to be made, what three are other tests must be made? (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) -----CORRECT ANSWER--------------Slump, air content, temperature The supporting surface on which specimens are stored shall be level within _____. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) -----CORRECT ANSWER--------------20 mm/m (1/4 in/ft) For concrete with a slump of less than 1 in. [25 mm], the test specimens must be consolidated by _____. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) -----CORRECT ANSWER-------------- Vibration If the concrete is to be consolidated by vibration, a standard 4 by 8 in. [100 mm by 200 mm] cylinder mold must be filled in _____ equal layers. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) -----CORRECT ANSWER--------------2 When rodding a standard 6 by 12 in [150 mm by 300 mm] cylinder, each layer must be rodded _____ times. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) -----CORRECT ANSWER-------------- 25 When rodding each upper layer of concrete in a cylinder, the tamping rod should penetrate into the underlying layer by about _____. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) ----- CORRECT ANSWER--------------25 mm (1 in) When using an internal vibrator to consolidate a 6 by 12 in. [150 mm by 300 mm] compressive strength test specimen, the vibrator must be inserted at _____ different points for each layer. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) -----CORRECT ANSWER---- ----------2 When consolidating a flexural strength test specimen by rodding, rod one stroke for each _____ of top surface area. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) -----CORRECT ANSWER---- ----------14 cm2 (2 in2) When internal vibration is used to consolidate a standard flexural strength test specimen, the technician should insert the vibrator at intervals not exceeding _____ along the center line of the beam. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) -----CORRECT ANSWER--------------150 mm (6 in) Concrete mixtures with specified strengths of 6000 psi [40 MPa] or greater shall have an initial curing temperature between __________. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) ----- CORRECT ANSWER--------------20 and 26 C (68-78 F) Up to 48 hours after molding, test specimens that are to be standard cured shall be stored in a temperature range between _____ to _____. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) -----CORRECT ANSWER--------------16 to 27 C (60-80 F) T or F: Upon completion of initial curing, the test specimens may be left in their molds and sealed in plastic bags. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) -----CORRECT ANSWER-------------- False; specimens are to be demolished and placed in water storage tanks or moist rooms with free water at a temperature of 23.0 +/- 2.0 C (73.5 +/- 3.5 F) During transportation, test specimens must be protected from damage due to ___, ___, and ____. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) -----CORRECT ANSWER--------------Jarring, freezing temperatures, moisture loss Specimens shall not be transported until _____ after final set. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) ----- CORRECT ANSWER--------------8 h Transportation time shall not exceed ___. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) -----CORRECT ANSWER---- ----------4 h Standard Curing is the curing method used when test specimens are to be used for _________. (C31/C31M - 19, Making and Curing Concrete Test Specimens in the Field) -----CORRECT ANSWER--------------Acceptance testing for specific strength, checking the adequacy of the mixture proportions for strength, and quality control (Strength, not framework) Strength test specimens transported from the field to the testing laboratory must be (written test practice) A. Protected from jarring B. Protected from moisture loss C. Protected from freezing D. A and B E. A,B, C -----CORRECT ANSWER--------------E.A, B, C Test for slump and air content must be started within __ after obtaining the final portion of the composite sample. (Written test practice) A. 5 min B. 10 min C. 15 min D. 30 min -----CORRECT ANSWER--------------A. 5 min The minimum size for samples to be used for strength tests is: (written practice test) A. 14 L (.5 ft3) B. 28 L (1 ft3) C. 57 L (2 ft3) D. 85 L (3 ft3) -----CORRECT ANSWER--------------B. 28 L (1 ft3) T or F: After strike off of the measure used to determine density, a small quandary of concrete may be added to correct deficiency (written practice) A. True B. False -----CORRECT ANSWER--------------B. False For normal strength concretes, what temperature range must be maintained for test cylinders during initial curing? (Written practice) A. 0-16 C (32 to 60 F) B. 16-27 C (60 to 80 F) C. 27 to 49 C (80 to 120 F) -----CORRECT ANSWER--------------B. 16-27 C (60 to 80 F) T or F: When the concrete contains large aggregate, the testing technician should wet-sieve the sample before making density (unit weight) tests for use in yield computations. (Written practice) A. True B. False -----CORRECT ANSWER--------------B. False When determining the temperature of fresh concrete, what is the minimum amount of concrete cover in all directives around the sense of of the temperature measuring device? (Written practice) A. 25 mm (1 in) B. 50 mm (2 in) C. 75 mm (3 in) D. 130 mm (5 in) -----CORRECT ANSWER--------------C. 75 mm (3 in) T or F: The sides of the slump mold should be lightly tapped to consolidate the concrete in the mold. (Written questions) A. True B. False -----CORRECT ANSWER--------------B. False T or F: Unless specified otherwise, strength test specimens molded from concerted having a slump less than 25 mm (1 in) must be consolidated via vibration. (Written question) A. True B. False -----CORRECT ANSWER--------------A. True T or F: Test cylinders may be capped with a thin layer of portland cement paste which is permitted to harden and cure with the specimen. (Written question) A. True B. False -----CORRECT ANSWER--------------A. True Tamping rod should be (written question) A. Flat B. Tapered C. Pointy D. None of the above -----CORRECT ANSWER--------------D. None of the above Start molding strength test specimens within ________ after fabricating the composite sample. (Written test) A. 5 min B. 10 min C. 15 min D. 30 min -----CORRECT ANSWER--------------C. 15 min T or F: Representative samples are required for use in tests conducted for the purpose of determining compliance with the specifications for concrete quality. (Written question) A. True B. False -----CORRECT ANSWER--------------A. True T or F: Test method C173/C173M specifies a minimum time requirement for investing and agitating the meter to free concrete from the base. (Written) A. True B. False -----CORRECT ANSWER--------------A. True Aci 301 states a strength test should be performed every ______ CY, 318 says ______ CY (sampling c172) -----CORRECT ANSWER--------------100, 150 Collection of composite samples shall not exceed ___ mins (sampling, c172) -----CORRECT ANSWER--------------15 mins Start tests for slump, temp, air content within ___ mins after collecting last of composite, start molding for strength within _____ mins. (C172, sampling) -----CORRECT ANSWER--------------5, 15 - Stationary mixers = 2 or more portions - Paving mixers (are technically stationary) = 5 or more - revolving drum or agitators = 2 or more - Continous = 2 or more -----CORRECT ANSWER--------------- Slump measures: _____ and ________/__________ Does not measure ____________ __________ or __________ ----- CORRECT ANSWER--------------Consistency, mobility/fluidity Not water content or workability Measure slump to what increment? -----CORRECT ANSWER--------------.25 inch How high do you raise the mold when releasing? -----CORRECT ANSWER--------------12 in Plastic concrete is just concrete in its softer phase when you sample it ----- CORRECT ANSWER--------------- Slump can at most do __ inch aggregate and is sieved at __ in ----- CORRECT ANSWER--------------1.5, 1.5 Slump can have concrete added and striked off -----CORRECT ANSWER-- ------------- C31 making and curing is the one you struggled on! C29 is bulk density so not involved -----CORRECT ANSWER--------------- What can lower density indicate? (5) and why should you look out for it as a technician -----CORRECT ANSWER--------------1. Lower specific gravity 2. Higher air content 3. Higher water content 4. Change in proportions or ingredients 5. Lower cement concrete Over-yield happens aka greater volume of concrete and lower strengths/qualities Density test is C____ which makes it applicable for pressure air content C___ and bulk density C____ -----CORRECT ANSWER--------------C138 C231 C29 Density formula -----CORRECT ANSWER--------------D = Mtotal- Mmeasurer / volume Same as theoretical density Yield formula -----CORRECT ANSWER--------------Y = M/D Relative Yield -----CORRECT ANSWER--------------R = Yactual / Ydesign Cement Concrete formula -----CORRECT ANSWER--------------C actual = Cmass in batch / Yactual Air content formula -----CORRECT ANSWER--------------A = (Dtheoretical - Dactual / Dtheoretical) * 100 Or A = (Vbatch - Vactual/Vbatch) * 100 1 yd = 3 ft -----CORRECT ANSWER--------------- Density is reported to the nearest ____ lb/ft3 -----CORRECT ANSWER------ --------0.1 lb/ft3 Samples can be made with... -----CORRECT ANSWER--------------Steel, cast iron, or other non absorbent Must be water tight also