GRADED A+
⩥ How is a sample taken when sampling plastic concrete?
Answer: 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?
Answer: 3
⩥ What size sample is needed when casting 3 100mm x 200mm
cylinders?
Answer: Minimum 20L
⩥ What size sample is needed when casting 150mm x 300mm cylinders?
Answer: Minimum 30L
⩥ What size sample is needed when casting 150mm x 150mm x 535mm
beams?
Answer: Minimum 55L
, ⩥ How much extra sample is needed when more than 3
cylinders/specimens are to be cast?
Answer: Volume of the cylinders/specimens plus 10% extra
⩥ How much time is allowed for obtaining, transporting and remixing
the sample?
Answer: 10 minutes
⩥ If A sample contains aggregate larger than that appropriate for the size
of the moulds or equipment.
Answer: It must be wet-sieved prior to testing
⩥ Information required on reports
Answer: 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
Answer: 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