In the context of slump, what is the minimum slump allowed if the maximum is specified at 6 in.?

The minimum slump allowed when the maximum is specified at 6 inches is determined by the guidelines set forth in concrete specifications, which often allow for a certain range of acceptable slumps for different applications. In this case, if 6 inches is established as the maximum slump, a standard practice is to allow for a minimum slump that ensures the concrete remains workable and can achieve the desired performance in its application.

In many specifications, a minimum slump of approximately 3½ inches is commonly permissible when a maximum of 6 inches is specified. This range helps ensure that while the concrete is not too fluid (which could compromise strength or stability), it still retains enough workability for proper placement and finishing. This balance is critical in maintaining the integrity and performance of the final concrete mix while accommodating variations that may occur during the mixing or pouring process.

Other values, such as 5 inches, 4 inches, and 2 inches, may either exceed the standard minimum functional requirements for workability in this context or fall below acceptable levels that could lead to challenges in handling the concrete effectively.