AASHTO T 291-22

This test method describes the procedures for sampling and testing a soil for chloride ion content.

This standard is divided into two parts. The first part specifies the procedure for sampling and preparing the sample to size for testing. The second part delineates two test procedures (MethodsA or B) for the determination of the water-soluble chloride ion content in soil. Two methods are given as follows:
Section
Method A:
(Mohr Titration Method) (1 to 7) and (8 to 16)
Method B:
(pH/mV Meter Method) (1 to 7) and (17 to 28)

Method A is based on the Mohr procedure for determining chloride ion with silver nitrate. Method B utilizes a pH/mV meter. By comparing the mV readings to the calibration curve, determine the chloride ion content. 

The values stated in SI units are to be regarded as the standard.