AASHTO T153-20 pdf free download
AASHTO T153-20 pdf free download.Fineness of Hydraulic Cement by Air Permeability Apparatus.
4.4. Plunger—The plunger shall be constructed of austenitic stainless steel and shall fit into the cell with a clearance of not more than 0.1 mm. The bottom of the plunger shall sharply meet the lateral surfaces and shall be at right angles to the principal axis. An air vent shall be provided by means of a flat section 3.0 ± 0.3 mm wide on one side of the plunger. The top of the plunger shall be provided with a collar such that when the plunger is placed in the cell and the collar brought in contact with the top of the cell, the distance between the bottom of the plunger and the top of the perforated disk shall be 15 ± 1 mm.
4.5. Filter Paper—The filter paper shall be medium retentive, corresponding to Type 1, Grade B, in accordance with ASTM E832. The filter paper disks shall be circular, with smooth edges, and shall have the same diameter (see Note 2) as the inside of the cell.
Note 2—Filter paper disks that are too small may leave part of the sample adhering to the inner wall of the cell above the top disk. When too large in diameter, the disks have a tendency to buckle and cause erratic results.
4.6. Manometer—The U-tube manometer shall be constructed according to the design indicated in Figure 1, using nominal 9-mm outside diameter, standard-wall glass tubing. The top of one arm of the manometer shall form an airtight connection with the permeability cell. The manometer arm connected to the permeability cell shall have a midpoint line etched around the tube at 125 to 145 mm below the top side outlet and also others at distances of 15 ± 1 mm, 70 ± 1 mm, and
110 ± 1 mm above that line. A side outlet shall be provided at 250 to 305 mm above the bottom of the manometer for use in the evacuation of the manometer arm connected to the permeability cell. A positive airtight valve or clamp shall be provided on the side outlet not more than 50 mm from the manometer arm. The manometer shall be mounted firmly and in such a manner that the arms are vertical.
4.7. Manometer Liquid—The manometer shall be filled to the midpoint line with a nonvolatile, nonhygroscopic liquid of low viscosity and density, such as dibutyl phthalate
(dibutyl I ,2-benzenedicarboxylate) or a light grade of mineral oil. The fluid shall be free of debris.
4.8. Timer—The timer shall have a positive starting and stopping mechanism and shall be capable of being read to the nearest 0.5 s or less. The timer shall be accurate to 0.5 s or less for time intervals up to 60 s, and to 1 percent or less for time intervals of 60 to 300 s.
5. CALIBRATION OF APPARATUS
5.1. Sample—The calibration of the air permeability apparatus shall be made using the current lot of National Institute of Standards and Technology (NIST) Standard Reference Material No. 114 or No. 46h. The sample shall be at room temperature when tested.
5.2. Bulk Volume of compacted Bed of Powder—Determine the bulk volume of the compacted bed of powder by physical measurement or the mercury displacement method as follows:
5.2.1. Bulk Volune Determination by Physical Measurement—Place two filter papers in the permeability cell. Use a rod slightly smaller than the diameter of the cell to press down the edges of the filter paper flat on the perforated disk. Determine the dimensions of the permeability cell using a measuring device readable to 0.001 cm. Measure the inside diameter of the permeability cell near the perforated disk as well as the depth of the cell and the length of the plunger. AASHTO T153-20 pdf download.
