The Table of Contents for this section is available.
All aggregates shall meet the applicable requirements of this section except where other requirements are specified in another section covering a particular aggregate or its use for a particular application.
A list of sources of aggregates in North Carolina and adjoining states that have been approved by the Department, and the purposes for which these aggregates are acceptable, is on file at the Department's Laboratory in Raleigh. Where an aggregate meets specification requirements but has a history of unsatisfactory service performance, its use for construction purposes may be restricted by the Department. Such restriction will be noted on the list of approved sources.
Aggregates proposed to be used on a project which are from sources that are not listed as approved will be investigated upon request of the owner or Contractor. Approval of such sources will be based not only on the quality of the aggregate, but also on satisfactory production facilities and procedures. Except as otherwise provided herein, aggregates from unlisted sources which have already been produced may be used in the work provided they have been properly stockpiled in units of not less than 200 cubic yards and tests of representative samples of these aggregates indicate satisfactory compliance with the specifications.
When an aggregate source contains rock of more than 1 identifiable rock type or contains particles of visibly different degrees of weathering in amounts of 10 percent or more, each individual type, when separated from the total aggregate shall have a percentage of wear of not more than that specified for a particular use. Blending of aggregates from different sources will not be permitted if either of the aggregates fails to meet the specifications for soundness or resistance to abrasion.
1005-2 HANDLING AND STORING AGGREGATES.
Aggregates shall be handled in such a manner as to minimize segregation.
Sites for aggregate stockpiles shall be grubbed and cleaned prior to storing aggregates, and the ground surface shall be firm, smooth, and well drained. A cover of at least 3 inches of aggregate shall be maintained over the ground surface to avoid the inclusion of soil or foreign material. Stockpiles shall be built as to minimize segregation. When it is necessary to operate trucks or other equipment on a stockpile in the process of building the stockpile, it shall be done in a manner approved by the Engineer.
Stockpiles of different types or sizes of aggregates shall be spaced far enough apart, or else separated by suitable walls or partitions, to prevent the mixing of the aggregates.
Any method of stockpiling aggregate which allows the stockpile to become contaminated with foreign matter or causes excessive degradation of the aggregate will not be permitted. Excessive degradation will be determined by sieve tests of samples taken from any portion of the stockpile over which equipment has been operated, and failure of such samples to meet all grading requirements for the aggregate will be considered cause for discontinuance of such stockpiling procedure.
All standard sizes of coarse aggregate shall meet the gradation and any other requirements of Table 10051. Standard sizes of coarse aggregate are identified by numerical or alphabetical designation.
All standard sizes of fine aggregate shall meet the gradation and any other requirements of Table 10052.
(A) General:
Aggregates shall be tested in accordance with the requirements of this article except where other test procedures are required by other articles covering a particular application.
(B) Gradation:
Aggregates will be tested for gradation in accordance with AASHTO T27 and AASHTO T11, except that aggregate to be used in a base course or as a stabilizer aggregate will be tested for gradation in accordance with AASHTO T88 as modified by the Department. Copies of the modified test procedures are available upon request from the Materials and Tests Unit.
(C) Liquid Limit:
Aggregates will be tested for liquid limit in accordance with AASHTO T89 as modified by the Department. Copies of the modified test procedures are available upon request from the Materials and Tests Unit.
(D) Plasticity Index:
Aggregates will be tested for plasticity index in accordance
with AASHTO T90.
(E) Resistance to Abrasion (Percentage of Wear):
Aggregates will be tested for percentage of wear in accordance with AASHTO T96.
(F) Soundness:
Aggregates will be tested for soundness in accordance with AASHTO T104 using sodium sulfate.
It is the intent of these specifications that the gradation of
the aggregate be the middle of the range shown in Column B of
Table 10081. If, however, the average test results
for a lot are within the limits shown in Column B of Table 10081,
the gradation of the lot will be considered as acceptable.