ACI written exam questions and answers 2024

False. Relatively dense - The method of determining air content of concrete containing lightweight aggregate is the pressure method True - Is the following statement true or false? When making a test cylinder from concrete being used in construction, the field technician must also measure the slump of the concrete. Disregard the test and retest on another portion of the sample. - While the technician is checking the slump of the concrete, there is a decided falling away or shearing off of concrete from one side of the sample. What should the technician do? Determination that at least 8 hours has elapsed since final set. - Preparation of specimens for transport includes: 4.8% - If the aggregate correction factor for a given source of fine and coarse aggregate is found to be 0.2% in a pressure air meter, and an air content value of 5.0% is read on the gauge of the same air meter containing concrete with the same aggregate, what is the correct air content? Protected from jarring, moisture loss, and freezing - Strength test specimens transported from the field to the testing laboratory must be: 5 MInutes - Tests for slump and air content must be started within ________ after obtaining the final portion of the composite sample. 1 cubic foot - The minimum size for samples to be used for strength test is: False - Is the following statement true or false? After strike off of the measure used to determine density, a small quantity of concrete may be added to correct a deficiency. 60 to 80 degrees f (16 to 27 degrees C) - For normal strength concretes, what temperature range must be maintained for test cylinders during initial curing? False - Is the following statement true or false? When concrete contains large aggregate, the testing technician should wet-sieved the sample before making density (unit weight) tests for use in yield computations. 3 inches ( 75MM) - When determining the temperature of fresh mixed concrete, what is the minimum amount of concrete cover in all directions around the sensor of the temperature measuring device?