In concrete paving operations, good workability and resistance to segregation are important. As for the hardened concrete properties, good durability, adequate strength, and less volume change potential due to shrinkage and temperature variations are characteristics that will provide good performance of concrete pavement. For the concrete to have good workability, durability, and adequate strength, two conditions must be met:

The current coarse aggregate gradations in Item 421 are more or less gap graded, which has less total coarse aggregate volume in a unit volume of concrete compared with well graded aggregate. Concrete with gap graded aggregates tend to require more paste to achieve a desired workability. Concrete with more coarse aggregate volume per unit volume of concrete (optimized) tend to need less paste to fill the voids between the aggregate. Having less paste results in less heat of hydration, less drying shrinkage, and less potential for cracking. All these provide for better long-term pavement performance.