What is the Percent Maximum Density for modified base subgrade material?

The Percent Maximum Density for modified base subgrade material is typically set at 98 percent. This value is derived from compaction standards that ensure the subgrade material is dense enough to provide a stable foundation for roadways and other structures. Achieving 98 percent Maximum Density indicates that the material has been compacted effectively, minimizing voids and increasing the material's load-bearing capacity.

This standard is important because a well-compacted subgrade reduces the potential for settlement and improves the durability and longevity of the surface layers that will be placed on top. It also helps in maximizing the strength of the materials used, making sure they can support the anticipated loads throughout their service life.

In contrast, other density percentages, such as 90 percent, are typically reserved for more granular materials or less critical structural elements, while 100 percent would suggest an impractical or non-achievable level of compaction in real-world applications. Therefore, 98 percent is recognized as the threshold that balances compaction effectiveness with practical construction techniques for modified bases in subgrade situations.