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Contractor Quality Control

            The contractor shall perform all quality control tests including, but not limited to, tests on fine and course aggregates, moisture content, and slump.

            For fine aggregates, a sieve analysis should be performed twice a day from randomly-sampled material from storage bins or conveyor belts in accordance with ASTM C 136. Moisture content of the fines should be tested in comparison with ASTM C 566 or ASTM C 70.

            For course grain aggregates a sieve analysis should be made twice a day for each size of aggregate. Tests will be conducted using ASTM C 136 as guidelines from randomly sampled material.

            The slump tests should be performed for each lot in accordance with ASTM C 143 from the material randomly sampled from trucks at the plant site.

 

CONTROL CHART LIMITS FOR SLUMP AND AIR CONTENT

Based on Sample Size n=4

Control Parameter

Individual Measurements

Range Suspension Limit

 

Action Limit

Suspension Limit

 

Slump

+/- 1 inch (25 mm)

+/- 1.5 inch (38 mm)

+/- 2.4 inch (61 mm)

Air Content

+/- 1.2 percent

+/- 1.8 percent

+/- 2.8 percent