ACI Certification Practice Exam questions with correct answers

For 4x8 cylinders, how many layers and rod strokes to properly consolidate the concrete? Answer 2 layers, 25 strokes For 6x12 cylinders, how many layers and rod strokes to properly consolidate the concrete? Answer 3 layers, 25 rod strokes After rodding each layer, the sides of the molds should be tapped 10-15 times with a tapping rod? T/F Answer False It should be done with a rubber mallet When rodding the second and/or third layers, the rod must go through the current ;layer and penetrate the previous layer approximately 1" Answer True While rodding the top layer and the concrete becomes low, additional concrete must be added before the 25th stroke Answer True A tamping rod, flow, or trowel can be used to produce a smooth flat level surface on top of the cylinders Answer Tamping rod, flow, trowel, all the above All of the above is correct When a strength specimen is used for acceptance testing, quality control testing, or trial batching a mix design, which type of curing method should be used Answer Standard lab cure