Research of sampling and testing rates for project tests listed in the Guide Schedule shows that the risk of either rejecting "good" material or accepting "bad" material ranges from 20 percent to 40 percent. Use this baseline for sampling and testing. The frequency of testing for high-variablity materials should be increased for high-variability materials when testing results do not meet specifications.

Current Guide

• May 2020

Previous Guides

• August 2017