ACI Certification Exam Questions With Verified Answers, Latest UPDATED 2024/2025 | Scored A+

- Standard Test Method For Temperature of Freshly Mixed Hydraulic-Cement Concrete The sensor of the temperature measuring device shall be submerged a minimum of ______ inches into the freshly mixed concrete. Answer - 3" The temperature measuring device shall have a capacity of measuring temperature of freshly mixed concrete to ± ______ °F throughout a range of ____________. Answer - 1 degree, 30 degrees to 120 degrees The temperature measuring device shall be calibrated ______ , or whenever there is a question of ______ . Answer - Annually, accuracy 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 What must be done to the sample container prior to sampling the concrete? Answer - Dampen with water 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 How long must the temperature measuring device remain in the freshly mixed concrete? Answer - minimum of two minutes, maximum of five minutes ACI Certification Exam Questions With Verified Answers, Latest UPDATED 2024/2025 | Scored A+ The temperature of the concrete is reported to the nearest ______ °F Answer - 1 degree A maximum temperature of freshly mixed concrete is specified in ASTM C1064. True or False? Answer - False ASTM C172 Answer - Standard Practice for Sampling Freshly Mixed Concrete Sampling by this method is required when tests are to be made to determine _____ with specification requirements. Answer - Compliance This method covers sampling from four types of mixers, which are _____ , _____ , _____ , and _____ . Answer - Stationary mixers, paving mixers, revolving drum mixers and open top mixers The maximum allowable time between obtaining the first and final portions of a composite sample is _____ minutes. Answer - 15 Portions of a composite sample shall be thoroughly remixed before beginning tests on the sample. True or False? Answer - True 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 The molding of strength test specimens shall begin within _____ minutes after fabricating the composite sample. Answer - 15 The concrete sample must be protected from contamination and _____. Answer - Rapid evaporation The minimum size sample for making strength test specimens is _____. Answer - 1 cubic foot 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 - 2 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. Answer - 5 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 - 2 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 The composite sample from a truck mixer must be obtained from the _____ portion of the batch. Answer - middle 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 What must occur before a sample of concrete can be taken from a revolving drum mixer? (Oral Exam) Answer - All of the water must be added to the mixer Describe the different procedures that can be used to collect a sample of concrete from a stationary or revolving drum mixer. (Oral Exam) Answer - Repeatedly pass a receptacle through the entire discharge stream, Completely divert the discharge stream into a sample container What are the required steps for collecting a sample of concrete from a stationary or revolving drum mixer? (Oral Exam) Answer - Collect two or more portions of concrete, Take the portions at regularly spaced intervals, Take the portions from the middle of the batch Describe the procedure for collecting a sample of pavement concrete deposited on grade. (Oral Exam) Answer - Discharge the contents of the paving mixer, Obtain samples from at least five different portions of the pile What is the minimum size for a sample when strength test specimens are to be molded? (Oral Exam) Answer - 1 cubic foot (28 L) What is the maximum allowable time between obtaining the first and final portions of the composite sample? (Oral Exam) Answer - 15 min. What is required after the concrete sample has been transported to the place where tests are to be performed? (Oral Exam) Answer - Combine and remix the sample with a shovel What should be done if the concrete contains aggregate larger than is appropriate for the size of the molds or equipment being used? (Oral Exam) Answer - Wet sieving Start the tests for slump, temperature, and air content within how many minutes after obtaining the final portion of the composite sample? (Oral Exam) Answer - 5 min. Start molding specimens for strength tests within how many minutes after fabricating the composite sample? (Oral Exam) Answer - 15 min. From what must the concrete sample be protected? (Oral Exam) Answer - Sun, wind, rapid evaporation, and contamination ASTM C143 Answer - Standard Test Method for Slump of Hydraulic-Cement Concrete The slump test is applicable to plastic concrete with a maximum size aggregate of _____ . Answer - 1½ in. 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 in. sieve The mold for making the slump test is in the shape of _____. Answer - The frustum of a cone The height of the slump mold is _____. Answer - 12 in. The interior surface of the slump mold is allowed to have minor irregularities. True or False? Answer - False For use in the slump test, the end or both ends of the tamping rod must be _____. Answer - Rounded to a hemispherical tip The sample of concrete for use in making the slump test must be obtained in accordance with ASTM Standard _____. Answer - C172, Standard Practice for Sampling Freshly Mixed Concrete The slump mold should be in a dry condition before beginning the test. True or False? Answer - False The surface on which the slump mold will be placed must be _____. Answer - Flat, level, moist, nonabsorbent, and free of vibration The slump mold is filled in _____ layers. Answer - 3 Each layer should fill approximately _____ the volume of the mold. Answer - One-third The approximate concrete depth (in vertical distance) after placing the first layer is _____, and the second layer is _____. Answer - 2⅝ in. [70 mm], 6⅛ in. [160 mm] What is the specified number of roddings for each layer? Answer - 25 How 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 in. [25 mm] When rodding the bottom layer, the tamping rod must be _____ to uniformly distribute the strokes. Answer - Slightly inclined