Page 32 - Concrete-Technology-Interacted_Book_Prof-MIK_Neat

PART 3

Quality and standards

Statistical analysis
techniques in ACT

Concrete is notable as a material whose properties can vary widely depending on the
choice and proportions of aggregates, cement, water, additives etc., together with the
production technique. An associated feature is that even with a desired (target) mix the
inherent variability in the materials and the production process will inevitably result in a
final product that differs from the target requirement. Of course, provided the concrete
remains within specified tolerances on key attributes then the product is acceptable.
Effective management of concrete therefore must include a quantitative knowledge of the
key attributes, monitoring techniques, decision methods, their limitations and an ability
to interpret the measured values. Statistical techniques are consequently used extensively
to understand and compare variations between concrete batches, to modify and control
the production of concrete and to form the basis of Quality Control and Quality Assurance.

Within a short chapter it is impossible and not appropriate to provide an in-depth
coverage of statistical theory and the underpinning ideas from probability theory. An
emphasis is on statistical techniques that are exploited and applied explicitly to current
practical circumstances in ACT such as trends and errors, estimation of parameters,
checking test results, mix design, compliance and quality control. Initially each section
will concentrate on providing fundamental understanding and competence of the background
techniques that will be required and use will be made of relevant statistical tables and
formulae.

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