ACI 214R-11

Statistical procedures provide valuable tools for evaluating the results of concrete strength tests. Information derived from such procedures is valuable in defining design criteria, specifications, and other parameters needed for structural evaluation and repair. This guide discusses variations that occur in concrete strength and presents statistical procedures useful in interpreting these variations with respect to specified testing and criteria. Keywords: coefficient of variation; concrete strength; normal distribution; required overdesign; quality control; standard deviation; statistical methods