SAFETY WORKBOOK SOLVED QUESTIONS
COMPILATION
◉ When can unmetered water be added to the concrete?
Answer: Not at all.
◉ Do not allow the total number of revolution at mixing speed to
exceed:
Answer: 160 Revolutions
◉ After all materials have been charged into the transit mixer drum,
the concrete must be mixed at how many revolutions at the plant
before leaving for the project?
Answer: 70 to 100
◉ When the water meters / scales are calibrated, prior to
production, at what frequency should they be checked there after?
Answer: 3 moths
◉ To what accuracy should the scales for weighing cement ,
pozzolan, slag and aggregates at the plant be maintained
, Answer: 0.5% of maximum load normally handled
◉ For concrete containing a water-reducing retarding admixture, in
an agitator truck, the maximum time for depositing the concrete
shall not exceed:
Answer: 90 minutes
◉ If a load of concrete has been rejected due to excessive slump, the
concrete may remain in the transporting vehicle to reduce the
slump.
Answer: Is not allowed.
◉ Who places the orders for concrete with the producer?
Answer: The contractor
◉ The minimum normal sampling frequency for the chloride
content of structural concrete is:
Answer: 1 per design mix in use from the first day of production and
every 30 calendar days or less thereafter.
◉ In what moister condition are the aggregates on the approved
concrete mix designs?
Answer: SSD condition