An exterior air-entrained paving mix arrives below the specified slump after a long haul. The driver offers to add water at the chute until the crew likes the look. Which response is appropriate?
Correct Answer
C) Follow the approved adjustment procedure, retest slump and air, and reject the load if it cannot meet specification
Water added outside the approved procedure can raise water-cement ratio and disturb air content; the load needs controlled adjustment and retesting or rejection. Other choices: visual judgment, untested water addition, and bucket cement changes are not quality-controlled concrete practice.
Why This Is the Correct Answer
Water added outside the approved procedure can raise water-cement ratio and disturb air content; the load needs controlled adjustment and retesting or rejection.
Why the Other Options Are Wrong
Option A: The crew should accept the driver's judgment and place the load
The trap in A is Accept the driver's judgment and place the load. That selection is wrong because it leaves out the controlling Slump adjustment result: Follow the approved adjustment procedure, retest slump and air, and reject the load if it cannot meet.
Option B: Add water until finishing becomes easy, then skip testing
Choice B gives Add water until finishing becomes easy, then skip testing. Its specific error: the action skips the timing, documentation, or field-control step needed for Slump adjustment.
Option D: Add extra water and extra cement in equal buckets
In concrete work, Add extra water and extra cement in equal buckets is the wrong selection for Slump adjustment: it points to Add extra water and extra cement in equal buckets, but.
Memory Technique
Picture a tab on the jobsite; slump adjustment is solved by the action that leads to Follow the approved adjustment procedure, retest slump and air, and reject the load if it cannot meet specification.
Reference Hint
Open The Contractor's Guide to Quality Concrete Construction, 4th Ed., 2018; use the index entry or section for "Jobsite slump and air-content control" to confirm that Water added outside the approved procedure can raise water-cement ratio and disturb air content; the load needs controlled adjustment and retesting or rejection.
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