1.1 This test method describes the procedure and apparatus for determining a pH value of coarse-grained material conforming to Standard Specification C33/C33M and C330/C330M by use of a pH meter. The principal use of the test method is to supplement soil resistivity measurements to identify conditions under which the corrosion of metal embedded in the coarse-grained material, or in contact with the coarse-grained material may be sharply accentuated.
KeywordspH values, coarse grained material, corrosion of metal
Rationale: A pH test procedure does not exist for coarse-grained material. 1) D4972, The Standard Test Method for pH of Soils, does not work for coarse-grained material as most or all of the coarse-grained material is larger than the No. 10 sieve. D4972 -13, Section 5.3 verifies that this test is not appropriate for larger particle sizes. 5.3 For the purpose of this test method the test soil must be sieved through a No. 10 sieve (2 mm sieve mesh openings). Measurements on solids of soil fractions having particle sizes larger than 2 mm by this test method may be invalid. If soil or soil fractions with particles larger than 2 mm are used, it must be stated in the report since the results may be significantly different. 2) G51 - 95 (Reapproved 2012) Standard Test Method for Measuring pH of Soil for Use in Corrosion Testing, does not work for coarse-grained material either. This method is predominately used for in-place soil. It is also not appropriate to crush the coarse-grained material down so they pass the No. 10 sieve, as that would significantly misrepresent the material being placed in the field. 3) History: This standard was originally proposed under ASTM C09 jurisdiction and title Standard Test Method for Determining pH of Lightweight Aggregate. However C09 rejected it because this test is used for material placed in geotechnical applications and not in concrete
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
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