Design of normal concrete mixes
factors that have a major effect on the characteristics of
the concrete, but can, at least at the first stage, ignore
those which only have a minor effect on the concrete.
There is little point in devising a complex method of mix
design which takes into account factors which are
difficult to measure or which are unlikely to remain
constant during the progress of the job. The effects of
various factors on the properties of concrete are
described in Sections 2 and 3.
The principle behind the method described in this
publication is that from the restricted data usually
available at the mix design stage, mix proportions are
derived in an attempt to produce a concrete having the
required workability and strength.
In this publication two alternative test methods are used,
the slump test[15] which is more appropriate for the higher
workability mixes, and the Vebe time test[16] which is
particularly appropriate for those mixes which are to be
compacted by vibration. The compacting factor[17] is not
used in this method since it is not possible to establish
consistent relationships between it and the slump or Vebe
time tests. If required, it can be used as a control test.
the slump test[15] which is more appropriate for the higher
workability mixes, and the Vebe time test[16] which is
particularly appropriate for those mixes which are to be
compacted by vibration. The compacting factor[17] is not
used in this method since it is not possible to establish
consistent relationships between it and the slump or Vebe
time tests. If required, it can be used as a control test.
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