What is the maximum diameter of stone usually specified for general purpose concrete work?

For general purpose concrete work, the maximum diameter of stone, often referred to as aggregate size, is typically specified as 1 1/2 inches. This size strikes a balance between providing sufficient structural integrity and ensuring proper workability of the concrete mix.

Using aggregates that are too large can lead to difficulties in mixing and placing the concrete, as they may not fill in the voids between the smaller particles adequately. Conversely, smaller aggregates can lead to a denser mix but may increase the risk of shrinkage and cracking. Therefore, a maximum aggregate size of 1 1/2 inches is commonly chosen to achieve optimal performance in structural applications, where the concrete needs to support load and maintain durability.

This standard ensures that the concrete mixture maintains good flow characteristics while achieving a cohesive bond among the cement, aggregates, and any added additives. Additionally, following this guideline helps ensure that the concrete achieves its intended strength and durability for typical construction projects.