Compaction of a lime-stabilized area requires _______.

• A. High shear stress
• B. The moisture content be reduced to within the specified range
• C. Increased compaction speed
• D. Additional cement

Answer: (B)

Maintaining proper moisture during compaction is essential when lime-stabilized soils are compacted. Water is needed for lime hydration and the subsequent pozzolanic reactions with clay minerals, which form cementitious bonds that increase strength. These reactions and the density gained through compaction happen best within a specific moisture range, so keeping moisture within that target range allows the material to densify effectively. If moisture is too low, the mix becomes stiff and cannot compact to its maximum density; if moisture is too high, the mix becomes plastic and compaction yields poorer density and potential rutting, and lime reactions can be impaired. The other factors aren’t the controlling ones here: high shear stress isn’t the driving requirement for achieving density, compaction speed isn’t the main determinant, and adding cement would shift the system away from lime stabilization toward cement stabilization.