What test is used to determine the water absorption capacity of aggregates?

The water absorption test is specifically designed to measure the ability of aggregates to absorb water. This test involves immersing the aggregate sample in water for a specified period of time and then measuring the weight difference before and after immersion. The increase in weight indicates the amount of water absorbed by the aggregates, which is a critical factor in understanding the material's performance in concrete and other applications.

Understanding water absorption is essential because it affects the workability, durability, and strength of concrete. Aggregates with high water absorption can lead to issues such as increased porosity and reduced long-term strength. Therefore, this test provides valuable information for material selection and quality control in construction projects, making it an integral part of aggregate testing protocols.

Other tests, while important in assessing different properties of aggregates, do not directly measure water absorption. The hydraulic conductivity test evaluates the permeability of the aggregate material, the specific gravity test determines the density of the aggregates, and the shell test is not commonly recognized in the context of aggregate testing. Each of these tests serves distinct purposes but does not focus on the water absorption capacity in the way that the water absorption test does.