ACI EXAM Q&A 2023

This test method covers sampling from stationary, paving and truck mixers, and from agitating and non agitating equipment used to transport central mixed concrete - Answer- True When the concrete contains large aggregate, the testing technician should wet sieve the sample before making unit weight tests for use in yield computation - Answer- False - cant wet sieve unit weight Samples should be taken before 10% or after 90% of the batch has been discharged. - Answer- False Samples smaller than 28L (1 .) are allowed on routine air content, temperature, and slump tests - Answer- True Tests for slump and air content must be started within ___ after obtaining the final portion of the composite sample - Answer- 5 minutes Start molding strength test specimens within ___ after fabricating the composite sample - Answer- 15 minutes How do you regulate the rate of discharge of the batch from the revolving truck drum mixer or agitator - Answer- By the rate of revolution of the drum The mold of the shaper of a ___ - Answer- Frustum of a cone The top diameter is ___ and the diameter at the base is __ - Answer- 4",8" While the technician is checking the slump of the concrete, there is a decided falling away or shearing off of the concrete from one side of the sample. What should the technician do? - Answer- Disregard the test and retest on another portion of the sample The mold is filled in three equal layers by volume, which makes the first third at __ and the second third at ___ - Answer- 2 5/8, 6 1/8 The maximum size of aggregate allowed for slump test is - Answer- 1 1/2" When ridding the second and third layers the rod should penetrate through the layer and into the previous layer ___ - Answer- 1" The slump of the concrete was determined to be 4 5/16 what should be recorded as the slump - Answer- 4 1/4 - closest quarter What's is the maximum amount of time to complete the slump test - Answer- 2.5 m