Which of the following tests is used to assess the air content in fresh concrete?

The air content meter test is designed specifically to determine the amount of entrained air in fresh concrete. Air content is a critical factor in concrete as it affects workability, durability, and resistance to freezing and thawing cycles. The test usually involves using an air meter, which measures the air voids within the concrete mixture. Accurately assessing air content ensures that concrete mixes perform as intended in various environmental conditions.

The other tests, while important for other aspects of concrete assessment, do not measure air content. The bleeding test evaluates how much water rises to the surface of freshly placed concrete, which is more about water-cement ratio and segregation. The slump test measures the consistency or workability of the concrete mix, indicating how easily it can be placed and finished but does not provide any information on air content. The compression test assesses the strength of hardened concrete, focusing on how much load the concrete can withstand after it has set and cured, completely separate from air content considerations.