Rationale

D1990 is being revised to change the clarify the purpose of monitoring and to change the required statistical tests to determine if a monitoring sample is significantly lower than the sample upon which the design values are based from a Wilcoxon test (which compares the entire distribution) to a Melded Random Quantile test for strength properties and a Welch’s t-test for average properties. This allows more emphasis to be placed on the specific quantile or average of interest rather than the entire distribution. Section 8.2.1 is also being revised to no longer require a data reduction to monitoring samples based on the Grade Quality Index of the sample. GQI information will still be collected and reported.