ACI Concrete Field Testing Technician- Grade I 2024 Edition. Questions & Answers. Grade A+, Exams of Material Engineering

Download ACI Concrete Field Testing Technician- Grade I 2024 Edition. Questions & Answers. Grade A+ and more Exams Material Engineering in PDF only on Docsity! ACI Concrete Field Testing Technician- Grade I 2024 Edition. All Questions & Verified Correct Answers. Graded A+ A 6 by 12 in [150 mm by 300 mm] cylinder mold can be used for concrete containing aggregate with particles not exceeding _____ in size, without the need for wet sieving the concrete. - ANS2 in. [50 mm] A composite sample of concrete is required even if the only purpose for obtaining the sample is to determine temperature. True of False? - ANSFalse A mallet weighing ____ must be used to tap the sides of the bowl after rodding each layer. - ANS1.25 +- 0.50 lb. (600 +- 200 g) A maximum temperature of freshly mixed concrete is specified in ASTM C1064. True of False? - ANSFalse A plastic container can be used for the measure in this method. True or False? - ANSFalse, measure must be steel or another suitable metal According to ASTM C1064, what is one reason to take the temperature of concrete? - ANSVerify conformance to a specified requirement for temperature of concrete After completing the strike-off procedure, what must be done before weighing the measure and sample? - ANSClean off any excess concrete After consolidation of the final layer, an excess of concrete ____ above the top of the measure is considered optimum. - ANS1/8 in. [3 mm] After molding test specimens, you should wait two hours before moving them to the location of initial storage. True or False? - ANSFalse; the specimens must be moved immediately After rodding each layer, what should be done to the measure before adding another layer of concrete? - ANSTap the sides of the measure smartly 10 to 15 times with the mallet After the final rodding, the sides of the slump mold should should be tapped lightly with the tamping rod. True or False? - ANSFalse After the temperature of the concrete is read, what is required? - ANSReporting of temperature Air meter bowls used for this test must conform to ASTM _____ and be calibrated for volumee according to ASTM _____. - ANSC231, C29 ASTM Method gives standardized requirements for _____, _____, _____, and _____, of test specimens. - ANSMaking, curing, protecting, transporting At the end of the procedure, the air meter is _____. - ANSDisassembled and its contents examined Concrete mixtures with specified strengths of 6000 psi [40 MPa] or greater shall have an initial curing temperature between __________. - ANS68 and 78 degrees F [20 and 26 C] 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? - ANSFalse Cylinders made for the purpose of determining when a structure may be put into service shall be removed from the mold __________. - ANSAt the time of the removal of formwork Cylinders that are to be field cured are stored __________ and protected __________. - ANSIn or on the structure as near to the point of deposit of the concrete represented as possible; In as near as possible the same way as the formed work During transportation, test specimens must be protected from damage due to _____, _____, and _____. - ANSJarring, freezing temperatures, moisture loss Each layer should fill approximately _____ the volume of the mold. - ANSOne-third Field Curing is the curing method used when test specimens are to be used for __________. - ANSDetermination of whether the structure is capable of being put into service; Comparison with standard cured specimens test results or with results from various in-place test methods; Adequacy of curing and protection of concrete in the Structure, or Form or shoring removal time requirements For a measure of 0.5 ft^3 [14 L], what is the required number of strokes of the tamping rod for consolidation of each layer? - ANS25 For concrete with a slump of less than 1 in. [25 mm], the test specimens must be consolidated by _____. - ANSVibration For cylinders with a diameter of 6 in. [150 mm] or greater, the tamping rod must be a round, straight steel rod with a diameter of _____. - ANS5/8 +- 1/16 in [16 mm +- 2 mm] For use in the slump test, the end or both ends of the tamping rod must be _____. - ANSRounded to a hemispherical tip The composite sample for a paving mixer must represent a minimum of _____ different portions of the batch of concrete taken from the pile after discharge. - ANS5 The composite samples from a truck mixer must be obtained from the _____ portion of the batch. - ANSMiddle The concrete sample must be obtained in accodance with what ASTM method? - ANSC172 The concrete sample must be protected from contamination and _____. - ANSRapid evaporation The container for obtaining the concrete sample used in this procedure can be a _____, _____, or _____. - ANSMetal pan, wheelbarrow, flat, clean nonabsorbent mixing board The diameter of the tamping rod used in the test method is _____. - ANS5/8 in. [16 mm] The direct reading of the final liquid level in the neck of the air meter, is estimated to teh nearest _____. - ANS0.25% The height of the slump mold is _____. - ANS12 in. [300 mm] 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. True or False? - ANSFalse; the funnel must be used The interior surface of the slump mold is allowed to have minor irregularities. True or False? - ANSFalse The maximum allowable time between obtaining the first and final portions of a composite sample is _____ minutes. - ANS15 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. - ANS5 The maximum size aggregate allowed for this test method is _____. - ANS50 mm (2 in.) The maximum size aggregate allowed in this test method is_____. - ANS1 1/2 in. (37.5 mm) The measurement for slump is made from the top of the mold to what point of the concrete specimen? - ANSThe displaced original center of the top surface of the specimen The minimum frequency of an internal vibrator used in this procedure is _____. - ANS9000 vibrations per minute [150 Hz] The minimum size sample for making strength test specimens is _____. - ANS28 L (1ft^3) The mold for making the slump test is in the shape of _____. - ANSThe frustum of a cone The molding of strength test specimens shall begin within _____ minutes after fabricating the composite sample. - ANS15 The outside diameter or side dimension of the vibrating element must be at least _____ but not greater than _____. - ANS0.75 in. [19 mm], 1.50 in. [38 mm] The pressure method of determining air content can be used on concrete containing _____ _____ aggregate. - ANSRelatively Dense The pressure method of determining air content cannot be used on concrete containing the following types of aggregates, _____, _____, _____. - ANSLightweight, air-cooled blast furnace slag, or aggregates of high porosity The sample of concrete for use in making the slump test must be obained in accordance with ASTM Standard _____. - ANSC172, Standard Practice for Sampling Freshly Mixed Concrete The sample of concrete used for temperature determination must be rodded 25 times. True or False? - ANSFalse The sample of concrete used for this test is to be obtained in accordance with what ASTM Standard? - ANSC172 The sample of concrete used in molding test specimens must be obtained in accordance with what ASTM Standard? - ANSC172 The sample of concrete used in this test method must be obtained in accordance with what ASTM Standard? - ANSC172 The sensor of the temperature measuring device shall be submerged a minimum of _____ in. [_____mm] into the freshly mixed concrete. - ANS3 in. [75 mm] The slump mold is filled in _____ layers. - ANS3 The slump mold should be in a dry condition before beginning the test. True or False? - ANSFalse The slump of the concrete is measured and reported to the nearest _____. - ANS1/4 in. [5 mm] The slump test is applicable to plastic concrete with a maximum size aggregate of _____. - ANS1.5 in. [37.5 mm] The supporting surface on which specimens are stored shall be level within _____. - ANS1/4 in. per ft. [20 mm per m] The surface on which the slump mold will be placed must be _____. - ANSFlat, level, moist, nonabsorbent, and free of vibration The temperature and moisture environment for field cured cylinders must be __________. - ANSThe same as the structural work The temperature measuring device shall be calibrated _____, or whenever there is a question of _____. - ANSAnnually, accuracy The temperature measuring device shall have a capacity of measuring temperature of freshly mixed concrete to +- _____ degrees F [+- _____ C] throughout a range of _____. - ANS1 degree F [0.5 C], 30 degrees F to 120 F [0 C to 50 C] The temperature of concrete is reported to the nearest _____ degrees F [_____ C] - ANS1 degree F [0.5 C] The temperature of concrete may be measured in a wall form. True of False - ANSTrue The temperature of concrete may be measured in a wheelbarrow. True or False? - ANSTrue The volumetric method of determining air content of concrete can be used on concrete containing what types of aggregate? - ANSAll types of aggregate This method covers sampling from four types of mixtures which are _____, _____, _____, and _____. - ANSStationary mixers, paving mixers, revolving drum mixers, and open top mixers Transportation time shall not exceed _____. - ANS4h Up to 48 hours after molding, test specimens that are to be standard cured shall be stored in a temperature range between _____ to _____. - ANS60 and 70 degrees F [16 and 27 C] Upon completion of initial curing, the test specimens may be left in their molds and sealed in plastic bags. True or False? - ANSFalse; specimens are to be demoled and When filling the bowl of the air meter, the concrete must be placed in _____ layers of equal depth. - ANS2 When internal vibration is used to consolidate a standard flexural strength test specimen, the technician should insert the bibrator at intervals not exceeding _____ along the center line of the beam. - ANS6 in. [150 mm] When large amounts of alcohol are used, the direct reading will tend to indicate a _____ air content. - ANSHigher When raising the slump mold, it should not be rotated or twisted, True or False? - ANSTrue When rodding a standard 6 by 12 in [150 mm by 300 mm] cylinder, each layer must be rodded _____ times. - ANS25 When rodding each upper layer of concrete in a cylinder, the tamping rod should penetrate into the underlying layer by about _____. - ANS1 in. [25 mm] When rodding the bottom layer, the tamping rod must be _____ to uniformly distribute the strokes. - ANSSlightly inclined When rodding the concrete sample, what is the specified number of strokes required for each layer? - ANS25 When rodding the middle and the top layers, the tamping rod should penetrate into the layer below approximately _____. - ANS1 in. [25 mm] 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 this batch. - ANS2 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 - ANS2 When strenght specimens are to be made, what three other tests must be made? - ANSSlump, air content, temperature When the concrete contains aggregate larger than allowed for the slump test, the large aggregate must be _____. - ANSRemoved by wet sieving the sample over 1.5 in. [37.5 mm] sieve When the concrete contains aggregate larger than that permitted for a particular test method, the sample of concrete must be _____ _____ before making the test. - ANSWet sieved 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. - ANS2 Why is the isopropyl alcohol added to the meter? - ANSTo dispel any foam that may be on the surface of the water