Concrete Testing Procedures, Exams of Advanced Education

Download Concrete Testing Procedures and more Exams Advanced Education in PDF only on Docsity! ACI Exam Questions With 100% Correct Answers | Verified | Updated 2023-2024 Collecting a representative sample of concrete to be tested is as important as executing the test methods to obtain ___________ - Correct Answer-Accurate Results This practice covers sampling from four types of equipment, which are ____________ , ____________ , _____________ , and ______________. - Correct Answer-Paving Mixers, Stationary mixer, revolving mixer, continuous mixer. The elapsed time between obtaining the first and final portions of a composite sample shall not exceed ____________ - Correct Answer-15 Mins Portions of a composite sample shall be thoroughly remixed before beginning tests on the sample. T or F - Correct Answer-T Start test for slump, temperature, air content within __________ after obtaining the final portion of the composite sample. - Correct Answer-5 mins Start molding specimens for strength tests within __________ after fabricating the composite sample. - Correct Answer-15 mins The concrete sample must be protected from contamination and ___________. - Correct Answer-Evaporation The minimum size sample for making strength test specimens is _______. - Correct Answer-1 ft^3 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. - 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. - Correct Answer-5 When sampling from a revolving truck mixer, sample the concrete by collecting _______ or more portions take at regularly spaced intervals during discharge of the middle portion of the batch. - Correct 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. T or F - Correct Answer-F When the concrete contains aggregate larger than that permitted for a particular test method, the sample of concrete must be ________________ before making the test. - Correct Answer-Wet sieved The stem of the thermometer is submerged a minimum of __________ into the freshly mixed concrete. - Correct Answer-3 in The thermometer shall be capable of accurately measuring the temperature of freshly mixed concrete to ____________ throughout a range of _________ to ___________ . - Correct Answer-(+-1 F ) , (30-120 F) The thermometer shall be verified within ________. - Correct Answer-1 year The temperature of concrete may be measured in a wheelbarrow. T or F - Correct Answer-T The temperature of concrete may be measured in a wall form. T or F - Correct Answer- T A composite sample of concrete is required even if the only purpose for obtaining the sample is to determine temperature. T or F - Correct Answer-F What must be done to the sample container prior to sampling the concrete? - Correct Answer-Dampen / Wet it What must be done to the concrete surrounding the thermometer after the device is submerged in the fresh concrete? - Correct Answer-compacted 3 in around stem no voids. How long must the thermometer remain in the freshly mixed concrete? - Correct Answer-2-5 min After the temperature of the concrete is read, what is then required? - Correct Answer- Record the temperature The temperature of the concrete is recorded to the nearest ________. - Correct Answer-1 F There is a specified maximum temperature of freshly mixed concrete. T or F - Correct Answer-F The sample of concrete used for temperature determination must be rodded 25 times? T or F - Correct Answer-F When the concrete contains aggregate larger than allowed for the slump test, the large aggregate must be _____. - Correct Answer-Wet Sieved (1-1.5 in sieve) If vibration is the method of consolidation, the measure must be filled in _____ approximately equal layers. - Correct Answer-2 If, after consolidation of the final layer, the concrete level is 1/2 in. (13 mm) above the top of the measure, what should be done? - Correct Answer-Remove excess till only 1/8 in remains After completing the strike off procedure, what must be done before weighing the measure and sample? - Correct Answer-Remove excess from measure The pressure method of determining air content can be used on concrete containing __________ and ____________ aggregate. - Correct Answer-Normal Weight, Heavy Weight The pressure method of determining air content cannot be used on concrete containing the following: ___________ or ___________. - Correct Answer-lightweight aggregates, aggregates of high porosity What is the specified size of the mallet required for a typical air meter? - Correct Answer-1.25 lb +- 0.5 lb Wet screening may be necessary when the mix contains aggregate with a nominal maximum size greater then ________. - Correct Answer-1.5 in If the concrete sample is to be consolidated by rodding, the measure is filled in _____ layers. - Correct Answer-3 If the concrete sample is to be consolidated by vibration, the measure is filled in _____ layers. - Correct Answer-2 When rodding the concrete sample, what is the specified number of strokes required for each layer? - Correct Answer-25 Vibration of the concrete sample is not allowed when the slump of concrete exceeds _____. - Correct Answer-3 In rodding the sample how deep should the rod penetrate each layer? - Correct Answer- Completely through and at least 1 in into previous layer. After rodding each layer, what should be done to the measure before adding another layer of concrete? - Correct Answer-Tap with mallet 10-15 times evenly distributed around the measure. What tools may be used to strike off the top surface of the concrete following consolidation of the final layer? - Correct Answer-Strike off Plate or Bar The volumetric method of determining air content of concrete can be used on concrete containing what types of aggregate? - Correct Answer-Lightweight, Normal, and Heavy What are the requirements for the tamping rod used in this test method? - Correct Answer-Hemispherical tip, 4 inches longer in length then measure no more then 24 inches in length. What are the requirements for the strike off bar used in this test method? - Correct Answer-Must be 3/4" wide 12" long, 1/8" thick if metal, 1/4" thick if plastic. What is the approximate capacity of the measuring cup used to add water to the air meter? - Correct Answer-1 Quart What type of alcohol and concentration must be used in this test method? - Correct Answer-Isopropyl, 70% A mallet weighing _____________ must be used to tap the sides of the bowl after rodding each layer. - Correct Answer-1.25lb +- .5 lb The test must be preformed on concrete containing materials that pass the __________. - Correct Answer-1" Wet sieve When filing the measuring the bowl of the air meter, the concrete must be placed in ________ layers of equal volume. - Correct Answer-2 What is the specified number of strokes required when rodding each layer of concrete? - Correct Answer-25 It is necessary to tap the sides of the measuring bowl after each layer has been rodded. T or F - Correct Answer-T 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. T or F - Correct Answer-F (Need a Funnel) Upon final filling of the air meter with water, what part of the liquid level should be adjusted to teh zero mark on the meter? - Correct Answer-Meniscus How long should the air meter be inverted? - Correct Answer-5 seconds How many times does the rolling operation occur? - Correct Answer-At least twice no more then 3 Why is the isopropyl alcohol added to the meter? - Correct Answer-to dispel any foam The direct reading of the final liquid level, in the neck of the air meter, is estimated to the nearest ________. - Correct Answer-.25% The air content is greater than the 9% range of the meter, ___________________________________________. - Correct Answer-Add enough cups to hit in the 6-7 range. In order for an initial meter reading to be valid, the meter must not be leaking, the liquid level must be stabilize within 6 min, and the foam on the surface of the liquid must not be greater than 2 full percent divisions. T or F - Correct Answer-T If less than 1.25 L [2.5 pt] of alcohol are used, the air content is always indicated by the final meter reading. True or False? - Correct Answer-Correction Factor At the end of the procedure, the air meter is _________________________________________________. - Correct Answer- Dismantle and check for full agitation If portions of undistributed concrete are found in the air meter at the end of the test, ___________________________________________. - Correct Answer-You fail the test 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 _____. - Correct Answer-5/8 " The minimum frequency of an internal vibrator used in this procedure is _________. - Correct Answer-9000 VPM Concrete containing aggregate with particles not exceeding ______ can be used to cast specimens without the need for wet screening. - Correct Answer-2" For concrete with a slump of less than 1 in. [25 mm], the test specimens must be consolidated by _____. - 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. - Correct Answer-2 When rodding each upper layer of concrete in a cylinder, the tamping rod should penetrate into the underlying layer by about _____. - Correct Answer-1" When rodding a standard 6 by 12 in [150 mm by 300 mm] cylinder, each layer must be rodded _____ times. - Correct Answer-25 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. - Correct Answer-2