Unchanging concepts - Concrete Mix Design, Quality Control and Specification - page 247

Unchanging concepts
11.1 CASH PENALTY SPECIFICATION
The authors believe that a cash penalty basis can provide fully fair and
effective regulation of concrete strength (and thereby, quality). However,
many in the industry or its clients have been reluctant to accept it. The
most pressing reason why concrete might desirably incur a penalty is in
fairness to other suppliers who allowed in their quotation to supply the
specified strength in full and thereby failed to obtain the contract to supply.
If well-intentioned suppliers do not see this as an advantage, then so be it.
However, the section remains in the topic to satisfy the authors' conscience
that they have done everything reasonably possible to bring about this
desirable reform.
This section was first published by Day (1982b) as an article in Concrete
International: Design and Construction in 1982 under the title “Cash
Penalty Specifications Can Be Fair and Effective”. Permission granted by the
American Concrete Institute to reproduce it here is gratefully acknowledged.
A cash penalty of twice the cost of the extra cement that would have
been required to avoid defectiveness is proposed. It is shown in detail that
if this is based on the statistical analysis of any 30 consecutive 28-day test
results, very little inequity would result to either party (in contrast to the
substantial risk of inequity under current specifications based on inaccu-
rate, small sample criteria). The aspect of legal enforceability is considered
and examples are provided of a suitable cash penalty provision used in a
major Australian structure, and of several situations where cash penalty
provisions would have been desirable.
A good specification system accomplishes the following (Day, 1961):
1. Ensures the detection and penalisation of unsatisfactory concrete
2. Avoids the penalisation of good concrete
3. Encourages good quality control
4. Avoids any doubt of fairness and eliminates disputes
5. Is based on sound theoretical principles