Download ACI Concrete Field Testing Exam Prep: 130+ Questions & Answers and more Exams Construction Procedures in PDF only on Docsity!
ACI WRITTEN EXAM 2025/ACTUAL 130+QUESTIONS
AND ANSWERS|GRADED A+
The sensor of the temperature measureing device shall be submerged a minimum ofin ANS:->> - 3 (75mm) The temperature measureing device shall have a capacity of measuring temperature of freshly mixed conrcrete to +- degrees F throught a range of ANS:->> - 1(.5 degrees C), 30-120 (0- 50 degrees C) The temperature measuring device shall be calibrated , or whenever there is a question of ANS:->> - annually, accuracy The temp of concrete may be measured in a wheelbarrow ANS:->> - true the temp of concrete may be measured in a wall form ANS:->> - true A composite sample of concrete is required even if the only purpose for obtaining the sample is to determine temp. ANS:->> - false What must be done to the sample container prior to sampling the concrete **ANS:-
- dampen (with water)** what must be done to the concrete surrounding the temp measuring device after the device has submerged ANS:->> - Press concrete around measuring device How long must the temp device remain in the concrete ANS:->> - at least 2 minutes (but no more than 5) After temp of concrete is read, what then is required ANS:->> - reporting of
temp the temp of concrete to be measured to the nearest degree F ANS:->> - 1 (. degree C) According to the ASTM C1064 what is one reason to take the temp of concrete ANS:->> - verify conformance to a specified requirement for temp A max temp of concrete is specified in ASTM C1064 ANS:->> - False The sample of concrete used for temp determination must be rodded 25 times ANS:->> - False Sampling by this method is required when tests are to be made to determine with specification requirements ANS:->> - compliance The method covers sampling from four types of mixers which are , , , and ANS:->> - stationary mixes, 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 ANS:->> - 15 Portions of a composite sample shall be thoroughly remixed before beginning tests on the sample ANS:->> - True The maximum elapsed time allowed between obtaining the final portion of the composite sample and beginning the tests for slump, temp, and air content is minutes ANS:->> - 5 the molding of strength test specimens shall begin within minutes after fabricating the composite sample ANS:->> - 15
large aggregate must be ANS:->> - removed by wet sieving the sample over 1.5 in sieve The mold for making the slump test is the shape of ANS:->> - the frustum of a cone The height fo the slump mold is in ANS:->> - 12 The interior surface of the slump mold is allowed to have minor irregularities ANS:->> - false For use in the slump test, the end or both ends of the tamping rod must be ANS:-
- rounded the sample of concrete for use in making the slump test must be obtained in accordance with ASTM standard ANS:->> - C172 (Standard Practice for sampling freshly mixed concrete The slump mold should be in a dry condition before the beginning of the test ANS:-
- false the surface on which the slump mold will be placed must be ANS:->> - flat, level moist, nonabsorbent, free of vibration The slump mold is filled in layers ANS:->> - 3 Each layer should fill approx volume of the mold ANS:->> - One third The approx conrete depth after placing the first layer is , and after the second ANS:->> - 2 and 5/8 in (70mm), 6.125 in (160 mm) what is the specified number of rodding for each layer ANS:->> - 25
How deep should the tamping rodd penetrate each layer ANS:->> - 1st layer all the way then one inch into previous layer What must be done if the concrete drops below the top of the slump mold while the top layer is being rodded ANS:->> - add additional concrete Prior to lifting the mold, concrete must be removed from ANS:->> - the area surrounding base of the mold After final rodding the sides of the mold should be tapped lightly ANS:->> - False When raising the slump mold it should not be rotated or twisted ANS:->> - true how much time is allowed for lifting the slump mold ANS:->> - 5 +- 2 seconds The measurment for slump is made from the top of the mold to what point of the concrete ANS:->> - the displaced original center of the top surface of the specimen the slump of concrete is measure and reported to nearest ANS:->> - 1/4 in ( 5mm) How much time is allowed to conduct the slump test from beginning to completion ANS:->> - 2.5 minutes The diameter of the tamping rod used in this (density and air) method is ANS:->> - 5/ in (16mm) What is the required shape of the tamping rod ANS:->> - rounded What is the required minimum frequency of the vibrator used in this test method ANS:->> - 7000 vibrations per minute The outside diameter or side dimension of the vibrating element must be at least but not greater than ANS:->> -
When rodding the middle and top layers the tamping rod should penetrate in into the previous layer ANS:->> - 1 (25mm) If vibration is the method of consolidation, the measure must be filled in approx equal layers ANS:->> - 2 If after consolidation of the final layer the concrete layer is 1/2 in (13 mm) above the top of the measure, what should be done? ANS:->> - Remove a representative portion of the excess concrete with a trowel or scoop After consolidation of the final layer, an excess of concrete above the top of the measure is considered optimum ANS:->> - 1/8 in(3mm) After completing the strike off procedure, what must be done before weighing the measure and the sample ANS:->> - Clean off any excess concrete The pressure method of determining air content can be used on concrete containing aggregate ANS:->> - relatively dense The pressure method of determining air content can be used on concrete containing the following types of aggregate , , ANS:->> - lightweight, air cooled blast furnace slag, aggregates of high porosity What is the minimum allowable capacity of measuring bowl used in this test ANS:-
- 6 L (0.20 ft^3) What are the required characteristics of the tamping rod used in this test method ANS:->> - Round straight steel rod with a 16 mm (5/8 in) +- 2mm (1/16in) diameter. Hemispherical tip What is the specified size of the mallet required for this test when measuring bowl has a capacity of 0.5 ft^3 ANS:->> - 0.6+- .25kg (1.25+-0.5lbs)
The sample of concrete used for this test is to be obtained in accordance with astm Standard ANS:->>
- C The max size aggregate allowed for this method is ANS:->> - 50 mm (2in) If the concrete contians aggregate larger than max allowed it must be ANS:->> - wet sieved over a 1.5 in sieve vibration of the concrete sample is not allowed when slump exceeds ANS:->> - 75 mm (3in) When consolidating the concrete by vibration how many times should the vibrator be inserted into each layer ANS:->> - 3 What tools may be used to strike off top surface ANS:->> - strike off bar or acrylic plate The volumetric method of determining air content of concrete can be used on concrete containing what types of aggregates ANS:->> - All types of aggregates
It is necessary to tap the sides of the measuring bowl after each layer has been rodded ANS:->> - True The initial quantitiy of water and alcohol added to the air meter can be directly poured into the neck of the top section of the air meter ANS:->> - 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 ANS:->> - Bottom of the meniscus How long should the air meter be inverted and agitated ANS:->> - No more than five seconds at a time for 45 seconds How many times does the rolling operation occur ANS:->> - a minimum of 2, a max of 3 Why is the isopropyl alcohol added to the meter ANS:->> - 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 the nearest ANS:->> - 0.25 percent If the air content is greater than 9% range of the meter then ANS:->> - Calibrated cups of water are added to bring liquid in range 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 division ANS:-
- True If less than 1.25 L (2.5 pt) of alcohol are used, the air content is always indicated by the final meter reading ANS:->> - False, if air content is more than 9 percent the number of calibrated cups of must be added
if more than 1.25 L (2.5pt) of alcohol are used the final meter reading is adjusted using ANS:->> - a correction factor When large amounts of alcohol are used the direct reading will tend to indicate a air content ANS:->> - Higher At the end of the procedure the air meter is ANS:->> - disassembled and its contents are examined If portions of undisturbed concrete are found in the air meter at the end ANS:->> - the test is invalid ASTM Method C31 gives standardized rquirements for , , , and of test specimens ANS:->> - making, curing, protecting and transporting For cylinders with a diameter of 6 in or greater the tamping rod must be a round, straight steel rod with a diameter ANS:->> - 5/8 in +-1/16 in (16mm +-2mm) The minimum frequency of an internal vibrator used in this procedure ANS:->> - 9000 vibrations per minute (150Hz) The container for obtaining the concrete sample used in this procedure can be a , , , ANS:->> - Metal pan, wheelbarrow, flat clean nonabsorbent mixing board a 6 in by 12 in cylinder mold can be used for concrete containing aggregate with particles not exceeding in size, without the need for wet sieving concrete ANS:->> - 2 in (50 mm) The sample of concrete used in molding test specimens must be obtained in accordance with what ASTM ANS:->> - C
Concrete mixtures with spec strengths of 600 psi or greater shall have an initial curing temp between ANS:->> - 68 and 78 degrees F (20 and 26 C) Up to 48 hours after molding, test specimens that are to be standard cured should be stored ina temp range between ANS:->> - 60 and 80 degree F (16 and 27 C Upon completion of initial curing the test specimens may be left in their molds and sealed in plastic bags ANS:->> - False, specimens are to be demolded and placed in water storage tanks or moist rooms with free water at a temp of 73.5+3.5F (23. +2.0 C) During transportation, test specimens must be protected form damage due to , and ANS:->> - Jarring, freezing temps, moisture loss Specimens shall not be transported until after final set ANS:->> - 8h Transportation time shall not exceed ANS:->> - 4h Standard curing is the curing method used when ANS:->> - Acceptance testing for spec strength, checking the adequacy of mixture proportions for strength, quality control Field curing is the curing method used for when ANS:->> - Determination of whether structure is capable of being put into service cylinders that are to be field cured are stored and protected ANS:->> - In or on the structure as near to the point of deposit of the concrete represented as possible The temp and moisture environment for field cured cylinders must be ANS:->> - The same as the structural work Cylinders made for the purpose of determining when a structure may be put into
service shall be removed form the molds ANS:->> - at the time of removal of formwork
