ACI Practice Questions

[@charleswhitbourne1268]

-The theoretical density of a mixture is 151.2 lb/ CU FT. The measured density for the mixture is 142.6 lb/ CU FT. Calculate the gravimetric air content for the mixture. B - ((151.2 - 142.6) / 151.2) X 100 - 5.7% -When the coarse aggregate of a concrete mixture can be retained on a 2 inch sieve, we sieve a sufficient amount of material for the air content test over a: 1 ½ sieve. - When consolidation is by vibrating, place concrete in the measuring bowl of a type B pressure meter in 2 layers of approximately equal volume. - After closing both petcocks, pump air into the chamber until the dial is on the initial pressure line. False. - after consolidating a layer of concrete by vibration, strike the measuring bowl 10-15 times with a mallet? False. - after opening the main air valve between the chamber and measuring bowl of type B meter: Tap the sides of the bowl with the mallet. - After completion of the air test: release the pressure in the measuring bowl by opening both petcocks. - assume that the reading from the dial guage is 6.2% and the aggregate correction factor for the concrete mixture is .5%, the final air content for the mixture is: B 6.2- .5 - 5.7% - insert the vibrator how many times per layer? C - 3 times. - when consolidation is by vibration: A - Never continue vibrating long enough to cause froth to escape from the concrete. - ASTM C173 measures the total volume of air present in: B the mortar fraction only. - when the course aggregates of a concrete mixture can be retained on a 1 ½” Sieve, Wet sieve a sufficient amount of material for ASTM C173 over a 1” Sieve. - prior to adding any isopropyl alcohol to the meter, it is necessary to add at least 1 pint of water to the meter. - The rolling process should last approximately how long? 1 Minute - when the liquid level in the neck of the meter is considered stable? D - the liquid level does not change more than .25% is 2 minutes. - A test must be discarded if the amount of foam present in the neck is equivalent to 2% air content divisions, or more under the liquid level. - confirmation of the initial meter reading is obtained when the difference the initial and final meter reading are within .25 of eachother. - the final meter reading from the neck is found to be 5.25%. Three pints of alcohol were added with the water, giving a correction factor of .25. Thre was no need to add calibrated cups of water to the meter. Final air content is: A 5.25 - .25 = 5.0% - if the liquid level fails to stabilize in 6 minutes: Discard and rerun test with more alcohol.

[@hijinxignatius]

Thanks! I could hear and see the questions just fine.

[@adityakuware1144]

8:42 bro thought we wouldn’t notice the Wolf of Wall Street reference!

[@jedimasteryoda798]

If im hauling 8000 yds to a job, we’re doing business 😂

[@charleswhitbourne1268]

-The elapsed time between obtaining the first and final portions of a composite samples shall not exceed: 15 minutes. -When is it necessary to wet sieve a concrete sample? Wet sieving should be performed before the individual samples are combined into a composite sample. - Test for slump, temperature and air content shall be started within 5 minutes after obtaining the final portion of the composite sample. - When sampling from a paver mixer, it is permissible to place 3 shallow containers on the subgrade in order to obtain the needed portions of concrete. True. - Regulate the rate that the concrete is discharges from a revolving drum by Adjusting the rate of revolution of the drum. - after wet sieving a portion of a concrete sample any aggregate retained on the sieve: shall be discarded. - when sampling from a paving mixer obtain at least 5 portions from the discharge pile. - the primary objective when sampling concrete is to get a representative sample. - the slump test provides a sense of water content : False (it tests consistency) - a slump mold can be fabricated from materials other than metal? True. - A slump test is applicable to concrete having a nominal maximum aggregate size of 1.5”. - If the condition of a non metal mold is suspected of being out of tolerance, in comparison with a metal mold shall not differ more than .5”, otherwise non metal mold shall be taken out of service.

[@charleswhitbourne1268]

-If while rodding the 3rd layer of concrete the top of the concrete falls below the top of the mold: C - Stop, add concrete to maintain an excess then continue rod count where you left off. -Complete the slump test with interruptions from the start of filling the mold through the removal of the mold within an elapsed time of 2 ½ minutes. -The slump test is not applicable to non-plastic and non-cohesive concrete: True. -Report the slump to the nearest 0.25 Inch -Consolidate the concrete in the slump mold by vibration: D Never. -if after raising the mold there is shearing off, or falling away of material from the mass of the concrete: Disregard test and perform on another portion of the sample. -The size of the measure, used in determining the density of fresh concrete is based on the nominal maximum size of the course aggregate. -It is permissible to use the bowl from the volumetric meter to determine density: False - when a vibrator is used to consolidate concrete in the measure, fill the measure in 2 equal layers. -is it permissible to add a small quantity of concrete to the measure to correct a deficiency? True (before strike off) -yield represents the: volume of concrete produced per batch. - after consolidating a layer by vibrating, tap the outside of the measure10-15 times? False. - volume of a measure is .510 CUFT the net mass of concrete in the measure is 73.2 lbs. Calculate the density of concrete: C 72.3/ .510 = 141.8 -The total mass of all material in a batch of concrete is 26,520 lbs. measured density was 144.3, calculate yields: A - 26,520/ (144.3 X27) - 6.8 CU YD. - design yield for a batch is 8.5 CU YD, the actual yield for the batch is 8.7YD, Calculate relative Yield: A - 1.02

[@syedjaffery179]

thanks

[@schumi9xwdc]

I used a magnifying glass, that helped….these questions were more to trip you up than to teach, no wonder they can’t find inspectors anymore.

[@joseleos9363]

So these werent on the test?

[@danielledrake1590]

@@joseleos9363 I highly doubt these are on the actual test

[@mahmoudabouegila5360]

Thank you for this vedio

[@jesusgjchuza6491]

This’s nice, but trie to make it more visible & sound better, but good job.

[@Monewood]

🙏🏾

[@heterozombie]

Can't hear or see a thing

[@danielledrake1590]

Are any of these on the actual test? Thank you

[@osmaknn9778]

A Year later but yes almost all of these are

[@torsheen1]

pleeeeez can wright the questions and the answers

[@saquality7078]

Can u please share pdf copy