Placement window

Definition

The gap the crew may leave between lifts, which is not the truck's clock and gets confused with it.

Why It Matters

Read this beside the discharge limit, because as the trade usually states them the two collapse into one rule. The truck's clock runs from the moment cement meets water until the load leaves the drum, and it belongs to the batch plant and the schedule. This one belongs to the crew: a pour is continuous work, and the interval allowed between adjoining lifts is what decides whether the joint between them is sound or cold. The number is set by the project's own specification and not by any general rule, and the standard that governs ready-mixed concrete on private work is sold and not published, so a state highway specification is the public substitute a reader can actually check. Ask which specification the crews work to and what it says about an interruption, because the answer is a document and not a rule of thumb.