ACI Certification Exam Questions And Verified Answers 2024.

ASTM C172 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 computations. - Answer False 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 is in the shape of a ___________________. - Answer Frustrum of a Cone The top diameter of a slump cone 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