Normal Consistency Of Hydraulic Cement 5w2y65

“Normal Consistency of Hydraulic Cement” ASTM ( C 187-86) 1. Aim: This test method cover the determination of the normal consistency of hydraulic cement. That is by determining the amount of water required to prepare cement pastes for initial and final time of setting test.

2. Apparatus: 1.Weight and weighing devices. 2. Glass graduates. 3. Vicat apparatus with the plunger end, 10 mm in diameter. 4. Containers.

3. Procedure: 1- Weigh 400 g of cement twice for 2 samples. 2- Prepare the weight of water to be for one sample 30% the weight of the cement, and the other sample 26% of the weight of cement (w/c = 30% and 26% respectively). 3- In the first sample, add the cement to the water. 4- Start mixing till all the water is absorbed and a gel is formed. 5- Make sure no materials have collected on the sides of the bowel. 6- Form the cement paste into the approximate shape of a ball. 7- Fill the ring with the paste completely. 8- Remove the excess cement at the top of the ring. 9- Center the paste under the plunger end which shall be brought in with the surface of the paste. 10- Set the movable indicator to the upper zero mark of the scale or take an initial reading, and release the rod immediately. 11- Take a reading of penetration. 12- Repeat the same work for the second sample and take another reading. 13- Draw curve of results describing variation of penetration as a function of w/c ratio of samples. 14- Normal consistency is w/c ratio at 10mm penetration.

4. Calculations and Graph: w/c (%) 30 26

Weight of cement (g) 400 400

Weight of water (g) 120 104

Penetration (mm) 27 4

30% →27 mm x→10 mm 26%→ 4 mm By interpolation: (30-x)/(30-26)=(27-10)/(27-4) x=27.04 % = w/c (normal consistency)

5. Results: Normal consistency (w/c) = 27.04% to be used for initial and final setting times test (ASTM C 403).