ACI Concrete Field Testing Technician - Grade I Practice Exam

What is the specified size of the mallet required when the measuring bowl has a capacity of 14 L (0.5 ft³) or less?

1. 0.30 ± 0.15 kg (0.66 ± 0.33 lb.)

2. 0.60 ± 0.25 kg (1.25 ± 0.50 lb.)

3. 1.00 ± 0.50 kg (2.20 ± 1.10 lb.)

4. 1.50 ± 0.25 kg (3.31 ± 0.55 lb.)

The correct answer is: 0.60 ± 0.25 kg (1.25 ± 0.50 lb.)

The specified size of the mallet for a measuring bowl with a capacity of 14 L (0.5 ft³) or less is 0.60 ± 0.25 kg (1.25 ± 0.50 lb.). This specification is provided to ensure that the mallet delivers an appropriate amount of force when striking the sides of the measuring bowl, facilitating the proper consolidation and settling of the concrete mixture being tested. Using the correct mallet weight is crucial for achieving consistent and reliable test results. An undersized mallet may not adequately compact the concrete, while an oversized mallet could cause excessive vibration and lead to unintended segregation or anomalies in the sample. The specified range of weight for the mallet aligns with industry standards to ensure standardized testing procedures are followed for accurate measurement and assessment of concrete properties. Selecting this weight helps technicians perform tests effectively while also adhering to the guidelines set by organizations like ASTM and ACI. It’s important to note that the requirements may vary based on bowl size, and using a mallet that is heavier or lighter than specified could compromise the integrity of the test results, which is why knowing the correct mallet weight is key for any technician involved in concrete testing.