ASTM C786/C786M-25

Podrobné informace

Označení: ASTM C786/C786M-25

Datum vydání: 01.04.2025

Stran: 4

Země: Americká technická norma

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Anotace

This test method covers wet sieving techniques for determination of fineness of hydraulic cement and raw materials by means of the No. 50, No. 100, and No. 200 sieves. The following apparatus shall be utilized: wet test sieves; spray nozzle; pressure gage; balance; weights; brush; dry test sieves; and NBS SRM No. 1004 (glass bead standard). Dry sieve standardization shall be performed by determining the correction factors and by preparing the standard samples. Wet sieve calibration shall follow and shall utilize the sieve correction factor. The procedure for wet sieving shall include the following: weighing of the sample; recording the weight and transferring the sample quantitatively to a clean dry sieve; wetting the sample thoroughly with a gentle stream of water; removing the sieve from under the nozzle and adjusting the pressure of the spray nozzle; returning the sieve to its position under the nozzle and washing it; moving the sieve in the spray with a circular motion; rinsing the sieve with distilled or deionized water immediately after removing it from the spray; blotting the lower surface of the screen cloth with a damp, clean cloth; drying the sieve and residue in an oven or over a hot plate; cooling the sieve; brushing the residue from the sieve; and weighing the sieve on a balance.


Keywords:
fineness, hydraulic cement and raw materials, sieve,, ICS Number Code 91.100.10 (Cement. Gypsum. Lime. Mortar)