3126Fine Aggregate for Concrete

3126.1SCOPE

Provide fine Aggregate for use in concrete.

3126.2REQUIREMENTS

A General Provide fine Aggregate consisting of clean, sound, durable particles, uniform in quality and free from wood, bark, roots, and other deleterious Material. The Engineer may consider the following as the basis for acceptance of fine Aggregate for Portland cement concrete:

geological formations or deposits

the Concrete Engineer Provide fine Aggregate from natural sand. If producing fine and coarse Aggregates simultaneously from natural Gravel deposits during the same operation, the Contractor may provide fine Aggregate containing particles of crushed rock with the approval of the Concrete Engineer. B Quality B.1 Washing Wash the fine Aggregate. B.2 Deleterious Material Provide fine Aggregate containing a cumulative quantity of deleterious Materials in accordance with Table 3126.2-1. Table 3126.2-1 Deleterious Materials Quality Test Maximum Percent by Weight Shale, Alkali, Mica, and Soft and Flaky Particles, Cumulative Total 2.5 Coal and Lignite, Cumulative Total 0.3 B.3 Organic Impurities Provide fine Aggregate free of injurious quantities of organic impurities. The Concrete Engineer will reject Aggregates that produce a color darker than the standard color when tested in accordance with AASHTO T 21 Standard Method of Test for Organic Impurities in Fine Aggregates for Concrete, unless the mortar specimens pass the mortar strength requirements specified in 3126.2B.4, “Structural Strength.” B.4 Structural Strength The Engineer will test the structural strength of fine Aggregate in mortar specimens in accordance with AASHTO T 71 Standard Method of Test for Effect of Organic Impurities in Fine

Aggregate on Strength of Mortar,” and Table 3126.2-2. The Engineer will prepare control mortar specimens using Ottawa sand with a Fineness Modulus (FM) from 2.30 to 2.50 for comparison with the proposed fine Aggregate. Table 3126.2-2 Structural Strength in Fine Aggregate Mortar Specimens Containing: Compressive Strength Type I/II Portland cement ≥ 90 percent of control at 7 Calendar Days Type III Portland cement ≥ 90 percent of control at 3 Calendar Days C Gradation Requirements Produce fine Aggregate in accordance with the gradation requirements in Table 3126.2-3. Table 3126.2-3 Fine Aggregate Gradation Requirements Sieve Size Percent Passing* 3/8 inch 100 No. 4 95 – 100 No. 8 80 – 100 No. 16 55 – 85 No. 30 30 – 60 No. 50 5 – 30 No. 100 0 – 10 No. 200 0 – 2.5 * Percent passing by weight through square opening Sieves. D Requirements for Uniformity of Grading The uniformity of grading is determined by the Fineness Modulus (FM) of the fine A ggregate. Both the Engineer and Contractor will determine the FM of fine Aggregate in accordance with the Concrete Manual. The established FM is available on the Department Concrete Engineering website. Do not allow the Material to deviate from the FM by greater than 0.20. Contact the Engineer, in conjunction with the Concrete Engineer, for an adjustment if the FM approaches the tolerance limit.

3126.3SAMPLING AND TESTING

Provide fine Aggregates in accordance with Table 3126.3-1. Table 3126.3-1 Preliminary Fine Aggregate Testing Aggregate Notification and Testing Required New source Notify the Engineer at least 30 Calendar Days before use. Perform new source concrete Aggregate testing. Previously tested Aggregate Notify the Engineer at least 14 Calendar Days before use. Perform additional testing as required by the Engineer in conjunction with the Concrete Engineer.

Sample and test fine Aggregate in accordance with Table 3126.3-2.

Table 3126.3-2 Fine Aggregate Test Methods Test Testing Method Sampling Concrete Manual Sieve analysis Concrete Manual Deleterious substances Laboratory Manual Method 1207 Quantity of Material passing the No. 200 Sieve Concrete Manual Organic impurities (color plate) AASHTO T 21 Structural strength AASHTO T 71 Specific gravity and absorption Laboratory Manual Method 1205 Alkali silica reactivity Laboratory Manual Method 1222