ACI Concrete Field Testing Technician - Grade I Practice Exam

How many layers should a measure be filled with when using rodding for consolidation?

1. 1

2. 2

3. 3

4. 4

The correct answer is: 3

When consolidating a concrete measure using the rodding method, it is standard practice to fill the measure in three layers. Each layer should be uniformly placed and then consolidated using a rod to ensure thorough compaction. By filling the measure in three distinct layers, you allow adequate opportunity for the air to escape and the concrete to achieve proper density, minimizing the effect of air entrapment that can lead to inconsistencies in test results. Rodding each layer typically involves using a straight, rounded end rod to poke the concrete throughout the layer, which helps to eliminate pockets of air and ensures that the material flows into corners and covers the bottom fully. After consolidating each layer, the process is repeated for the subsequent layers, maintaining the specified number to witness effective consolidation. This method is prescribed in guidelines to ensure uniformity and reliability in testing, making it critical for technicians to adhere to this procedure during the consolidation phase of concrete sampling.