University of New Mexico

Civil Engineering Department

Civil Engineering Materials Laboratory, CE 305L

FINENESS OF HYDRAULIC CEMENT BY AIR PERMEABILITY APPARATUS

ASTM C204

Scope

This test method covers the determination of the fineness of hydraulic cement, using the Blaine air permeability apparatus, in terms of the specific surface expressed as total surface area in square meters per kilogram of cement. The Blaine apparatus draws a defined volume of air through a prepared bed of cement of defined porosity.

Apparatus

Blaine air permeability apparatus (shown below) – Consists of a manometer, a stainless steel permeability cell, a perforated metal disk, and a stainless steel plunger.

Balance – 0.001g resolution.

Timer – 0.5s resolution.

Materials

Hydraulic Cement ~ 3g.

Filter Paper – Type 1, Grade B (Federal Specification for Filtering Paper (UU-P-236) with a 12.7 mm diameter.

Manometer Liquid – light grade of mineral oil (low viscosity and density).

NIST Standard Reference Material No. 114.

Procedure

Download Procedure for Fineness of Hydraulic Cement

Download Excel form for Fineness of Hydraulic Cement

•  Place approximately 4 oz of cement in a small covered jar or tin container. Shake vigorously for 2 minutes to fluff the cement and break up lumps and agglomerates. Allow the covered container to stand for 2 minutes, then remove the cover and stir gently to homogenize the sample.

•  Weigh out the cement to the nearest 0.001g. The weight of sample shall be determined as follows:

W = ρV (1- n )

where ρ is the density of the cement (3.15 g/cm³), n is a standard porosity of the bed (0.5) and V is the total volume of the cement bed determined by calibration (See ASTM for calibration procedure using NIST SRM No. 114). Prior calibration has established that this volume is:

V = 1.8372 cm³

•  Gently seat the perforated metal disk in the permeability cell on the ledge at the bottom of the cell using a rod having a diameter slightly smaller than that of the cell. Place a filter paper on the metal disk and press the edges down with this same rod.

•  Place the cement in the cell on top of the first filter paper. Tap the side of the cell lightly in order to level the bed of cement. Place a second filter paper on this bed of cement.

•  Compress the cement with the plunger until the plunger collar contacts the top of the cell. Slowly withdraw the plunger a short distance, rotate the plunger 90°, and compress the cement a second time until the collar contacts the top of the cell. Slowly remove the plunger. Note that fresh filter papers must be used for each determination.

View a Quicktime Movie of compressing the hydaulic cement

•  Attach the permeability cell to the manometer tube (use a little stopcock grease to ensure an airtight connection).

•  Slowly evacuate the air in the right arm of the manometer using the pressure bulb until the liquid reaches the top mark, and then close the manometer valve. The liquid will start to slowly lower because of airflow through the cement sample into the manometer.

•  Start the timer when the bottom of the meniscus of the liquid reaches the second mark from the top and stop the timer when the bottom of the meniscus reaches the third mark (next to the bottom mark). Record this time, T , to the nearest 1 second.

View a Quicktime Movie of timing the liquid

•  Calculate the specific surface values in accordance with the following equation:

where T is the measured time interval of the manometer drop for the test sample, S_s is the specific surface area of the standard reference material (NIST SRM #114), and T_s is the measured time interval of the manometer drop for the SRM. This equation is valid for cement tests performed at the same temperature as the standard reference test, and at the same porosity ( n =0.5). Prior calibration has established that these SRM values are as follows:

S_s= 377.4 m²/kg, and

T_s = 92.2 s

Report

1) The specific surface area to the nearest 1 m²/kg.