Examination of Aggregates for Concrete (ASTM C295)

ASTM C295 is one component of a testing program to assess the suitability of an aggregate for use in concrete. It can be performed in conjunction with tests listed in ASTM C33, Specification for Concrete Aggregates, or conducted independently as an indicator of general aggregate quality. Related tests often performed in conjunction with ASTM C295 include petrographic number (PN), scratch hardness, and percentage of flat and elongated particles.

The test is performed on:

• Natural sand
• Natural gravel
• Manufactured aggregate of all sizes
• Crushed and partially crushed stone
• Drilled rock core
• Ledge rock

The detailed petrographic report will provide the following information:

• Aggregate lithology (rock types) with quantitative data of rock and mineral types presented in table format
• Identification of characteristics that may influence the aggregate’s performance in concrete, and quantification of amounts of potentially chemically or physically deleterious constituents
• Narrative description of mineralogical composition, texture, presence of coatings, and physical condition of particles
• Photodocumentation and photomicrographs of pertinent observations