AND ANSWERS SURE A+
✔✔Slump Test time requirement - ✔✔Done in 2 minutes or less. If 2 operators testing, 4
minutes or less.
✔✔When measuring slump read to the nearest how many mm? - ✔✔5
✔✔Freshly Mixed Concrete Temperature cover, range, accuracy, calibration accuracy,
calibration separation - ✔✔Sample container made large enough to ensure 75mm of
concrete is in all directions around the temperature sensor or at least 3 times the
nominal maximum size of the aggregate, Must measure from 0 to 50 degrees C and be
within 0.5 degrees C accuracy. Calibration must be within 0.2 degrees C.
✔✔How long do you have to take a temperature reading of your sample after you have
collected it? - ✔✔5 minutes.
✔✔Slump Flow Test - ✔✔Fill cone to slightly above, don't rod, strike off, raise
immediately 225mm +/- 75mm above surface in approximately 3 +/- 1 seconds. Allow
maximum spread or 2 minutes to pass. This test should take 3 minutes. Report to the
nearest 10mm.
, ✔✔ Sampling from a mixer/truck agitator- Where is sample taken? - ✔✔Between 10%
and 90% (Not when testing with Super P)
✔✔How is a sample taken when sampling plastic concrete? - ✔✔Either pass a
receptacle completely through a discharge stream OR divert a discharge stream
completely into a sampling container.
✔✔How many grab samples are needed when testing for uniformity of samples? - ✔✔3
✔✔What size sample is needed when casting 3 100mm x 200mm cylinders? -
✔✔Minimum 20L
✔✔What size sample is needed when casting 150mm x 300mm cylinders? -
✔✔Minimum 30L
✔✔What size sample is needed when casting 150mm x 150mm x 535mm beams? -
✔✔Minimum 55L
✔✔How much extra sample is needed when more than 3 cylinders/specimens are to be
cast? - ✔✔Volume of the cylinders/specimens plus 10% extra
✔✔How much time is allowed for obtaining, transporting and remixing the sample? -
✔✔10 minutes
✔✔If A sample contains aggregate larger than that appropriate for the size of the
moulds or equipment. - ✔✔It must be wet-sieved prior to testing
✔✔Information required on reports - ✔✔Conc mix no, Sample source, Batch time/date,
Sample time/date, Project site, Sample location if different, Location of conc in structure,
Technician name, Lab name/address, Signature of test report reviewer, Any deviation
from test procedures
✔✔What is Air Content - ✔✔The volume of air voids of plastic concrete, exclusive of
pore space in aggregate particles, determined through observations of the change of air
volume in concrete with a change in pressure.
✔✔What is Slump - ✔✔A measure of consistency of freshly mixed hydraulic cement
concrete, equal to the subsidence, measured to the next 5mm, of the moulded
substance immediately after the removal of the slump cone
✔✔Slump Flow - ✔✔The horizontal spread of concrete immediately upon removal of the
slump cone as a measure of the unconfined fluidity of concrete giving a relative degree
of indication of the degree to which concrete can travel