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siliceous or carbonate 2
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Hoaokapohaku
Geotechnical
Unless you have a special application that requires a very specific kind of aggregate, what type of aggregate you get most often depends on what is economically available in a given region. Specifications normally specify aggregate properties that can be met by wide variety of aggregates. Normally, it's best to start with ASTM C-33 or your local State DOT specs (in the USA, equivalent agencies elsewhere), evaluate the spec, and then just specify exceptions or additions to the standard requirements as may be needed for your specific application.
If ASTM C-33 is used, sometimes local aggregates may not qualify under the grading requirements. However, within C-33 there are exceptions to the grading requirements such that an aggregate may be considered C-33 compliant even if it does not strictly comply with the C-33 requirements, but does have a satisfactory service record and is in compliance with the grading specifications of local public works specifying agencies.
Mix designs may not (usually don't) indicate the type of stone unless the type is specified, but do indicate test values that demonstrate compliance with the performance criteria specified.
If ASTM C-33 is used, sometimes local aggregates may not qualify under the grading requirements. However, within C-33 there are exceptions to the grading requirements such that an aggregate may be considered C-33 compliant even if it does not strictly comply with the C-33 requirements, but does have a satisfactory service record and is in compliance with the grading specifications of local public works specifying agencies.
Mix designs may not (usually don't) indicate the type of stone unless the type is specified, but do indicate test values that demonstrate compliance with the performance criteria specified.
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Hoa is correct. Aggregate type is not usually stated on mix design. Here's what I require to review a mix design...
1. Aggregate source
2. Statement of test results for no reactivity
3. Fineness modulus and statement of satisfactory historical performance if fineness modulus does not meet C33 requirements
4. Statement of satisfactory historical performance of the specific mix design
5. Gradations
6. Sources of all materials
7. Strength history including moving average
8. Strength gain curve for the mix design
Type of aggregate is dependent upon the area of production. Local or nearby aggregates will be first priority. Imported aggregates will be more expensive.
1. Aggregate source
2. Statement of test results for no reactivity
3. Fineness modulus and statement of satisfactory historical performance if fineness modulus does not meet C33 requirements
4. Statement of satisfactory historical performance of the specific mix design
5. Gradations
6. Sources of all materials
7. Strength history including moving average
8. Strength gain curve for the mix design
Type of aggregate is dependent upon the area of production. Local or nearby aggregates will be first priority. Imported aggregates will be more expensive.
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TXStructural
Structural
It is perfectly acceptable, and sometimes necessary, to specify aggregate types. Specifically for exposed applications, the kind of rock is specified for durability, appearance, or thermal characteristics (CTE/COTE). It is seldom specified otherwise, and is usually is just a function of the local sources or ready mix supplier. The easiest way to find out is to call the ready mix companies near the job and ask about the aggregates.
One of the things we are trying to do with ACI 301 is to get changes allowing performance design (and to remove things like slump specification and limitations - but still allow the test for batch-to-batch consistency purposes.) We would like designers to be able to list performance criteria rather than recipes and limits which may or may not work for the application.
One of the things we are trying to do with ACI 301 is to get changes allowing performance design (and to remove things like slump specification and limitations - but still allow the test for batch-to-batch consistency purposes.) We would like designers to be able to list performance criteria rather than recipes and limits which may or may not work for the application.
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