Commonwealth of Pennsylvania PA Test Method No. 507 Department of Transportation 6 Pages 1. SCOPE LABORATORY TESTING SECTION Method of Test for BULK SPECIFIC GRAVITY (SATURATED SURFACE-DRY BASIS), ABSORPTION, AND SOLID VOLUME OF SLAG COARSE AGGREGATE 1.1 This method of test is intended for use in making, in the field, the determinations of bulk specific gravity (saturated surface-dry), absorption, and the solid volume of slag coarse aggregate (Note 1). NOTE 1 - The bulk specific gravity (S.S.D) is the value generally desired for calculating proportions of aggregates to be used in portland cement concrete (It should be recognized that the value obtained by this test is not a true determination because of the variation within the material, however it is a satisfactory method). After having obtained numerous values, it is possible to arrive at an average value which is referred to as the "Bulk Specific Gravity Factor for Slag." 2. APPARATUS 2.1 Balance - The balance or scale shall be readable to at least 45.4 grams (0.1 lbs). 2.2 Tamping Rod - Refer to AASHTO T-19, Section 5 2.3 Measure - Refer to AASHTO T-19 and use a 0.03 cubic meter (one cubic foot) measure meeting the requirements specified in Section 5. 3. CALIBRATION OF MEASURE 3.1 Refer to AASHTO T-19, Section 8 4. SAMPLE 4.1 Select a sample representative of the material to be tested, in the combination of sizes to be used in the concrete, and mix thoroughly. Exercise care to prevent segregation of the material and to prevent evaporation of moisture from the material during the test.
Page 2 5. DETERMINATION OF SURFACE MOISTURE 5.1 Refer to AASHTO T-85 and do the following: 5.1.1 Obtain a sample in accordance with Section 7.2 and discard the material passing the 4.75 mm (No 4) sieve. Immediately weigh the resultant sample to the nearest 1.0 g and record the mass. Make all subsequent weighing to the nearest 1.0 g. 5.1.2 Roll the material in a large absorbent towel until all visible films of water are removed, although the surfaces of the particles still appear to be damp. The larger fragments may be individually wiped. Exercise care to prevent evaporation during operation of surface drying. Weigh the saturated surface dry sample immediately and record the mass. After recording the mass, dry the sample to constant mass for use in Section 6. 5.1.3 Subtract the surface dry mass obtained in Section 5.1.2 from the sample mass recorded in Section 5.1.1 and calculate the percentage of surface moisture from the following formula: 100 (A - B) = C B A = Original wet mass of the sample (Section 5.1.1) B = Surface-dry mass of the sample (Section 5.1.2) C = Percent of surface moisture 6. ABSORPTION 6.1 After drying the sample to constant mass, (Section 5.1.2) remove the sample from the source of heat and cool to room temperature. NOTE 2 - Never place hot material on a scale or balance. If the sample is too hot to handle, it is too hot to weigh accurately.
Page 3 6.2 Weigh the sample and calculate the percentage of absorption from the following formula: 100 (B - F) F = Absorption, percent B = Mass of sample, S.S.D (Section 5.1.2) F = Mass of sample after drying (Section 5.1.2) 7. LOOSE UNIT WEIGHT DETERMINATION OF SURFACE-DRY AGGREGATE 7.1 Refer to AASHTO T-19 and, using the "Shoveling Procedure" outlined in Section 12. Determine the wet unit weight of the aggregate by multiplying the net mass of the aggregate in the measure by the factor found as described in Section 3.1. The product is the Wet Loose Unit Weight of the material (Note 2). Keep the material intact in the container where it shall remain undisturbed for use in later Solid Volume Determinations. NOTE 3- Results with the same material shall check within 1.0 percent. 7.2 Calculate the Unit Weight of Surface-Dry Aggregate from the following formula: H x 100 D = E H = Loose Unit Weight of Wet Aggregate D = Percent of Surface Moisture + 100 percent E = Loose Unit Weight of Surface-Dry Aggregate
Page 4 8. DETERMINATION OF MASS PER SOLID VOLUME (kg/m 3 )(lbs/ft 3 ) 8.1 Compact the material retained in the container (Section 6.1), preferably by jigging, so that all of the pieces of aggregate are below the top surface of the measure. Inundate the aggregate with water, agitating or tapping the measure (Note 3) as the water is being added, in order to remove all of the entrapped air. After all of the aggregate has been covered with water, place the container with aggregate and water on a level platform scale. Add water to the measure to the point of overflowing and carefully wipe dry any water that may have spilled onto the outer surface of the measure or the platform scale. NOTE 4- A rubber mallet or a metal tamping rod may be used satisfactorily for tapping the measure in order to remove entrapped air while water is being added. 8.2 Calculate the Solid Volume by using the following formulas: J E K = V E 100 V = S = T S J = Loose Unit Weight of wet aggregate plus the mass of water required to fill the container E = Loose Unit Weight of the surface dry aggregate K = Unit Weight of water per cubic meter - 1000 kg (per cubic foot - 62.4 lbs.) S = Percent of Solids V = % volume of voids T = Mass per Solid Volume (kg/m 3 )(lbs./cu. ft.)
Page 5 9. BULK SPECIFIC GRAVITY OF SLAG AGGREGATE (S.S.D.) 9.1 Calculate the Bulk Specific Gravity of Slag Aggregate, (Saturated Surface-Dry Basis) from the following formula: T = K R T = Solid Volume (kg per cubic meter)(lbs. per cubic foot) K = Mass of Water per cubic meter -1000 kg (per cubic foot - 62.4 lbs.) R = Bulk Specific Gravity of Slag Aggregate, Saturated Surface Dry Basis 10. REFERENCES PTM 509 AASHTO T-85
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