FIELD SAMPLING AND TESTING MANUAL TESTING .
FIELD SAMPLING AND TESTING MANUAL . TESTING PROCEDURES . ... ND T 121 Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete . ND T 141 Sampling Freshly Mixed Concrete . ND T 152 Air Content of Freshly Mixed Concrete by the Pressure Method . ... This test defines the procedures used to obtain samples that will show the nature