NORMAL CONSİSTENT TESTTo determine the quantity of water required to produce a cement paste of standard consistency.The standard consistency is that consistency, which will permit the vicat plunger to penetrate to a point 5 to 7mm from the bottom of the vicat mould when tested as described below.APPARATUS1. VICAT APPARATUSThe vicat apparatus consists of a frame having a movable rod with a cap at one end and at the other end any one of the following attachment, which are interchangeable.i) Needle for determining the initial setting timeii) Needle for determining the final setting timeiii) Plunger for determining the standard consistency2.NEEDLESNEEDLE FOR INITIAL SETTING TIMEThe needle is having a cross sectional area of 1mm2. The end of the needle is flat.NEEDLE FOR FINAL SETTING TIMEThe needle is circular having a cross sectional area of 1mm2. The needle is fitted with a metal attachment. The end of the needle projects beyond the cutting edge of the hollowed out metal attachment.3.PLUNGER FOR STANDARD CONSISTANCYIt is of polished brass 10 ± 0.05mm in diameter with a projection at the upper end for insertion into the movable rod. The lower end is flat.MOVABLE RODMovable rod carries an indicator which moves over a graduated scale attached to the frame (certain models have an additional attachment of dash pot, which facilitates lowering of movable rod slowly).4. GRUADUATED SCALEGraduated scale is 40mm in length and the smallest division of scale is 1mm.5. VICAT MOULDSingle mould: – The vicat mould is in the foam of a frustum of a cone having an internal diameter of 60+/-0.5mm at the top, 70 +/- 0.5mm at the bottom and height 40 +/_ 0.5mm.Split type vicat mould:- The split type vicat mould is used as an alternative to single mould. This mould consist of a split ring having an internal diameter 80+/- 0.1mm and a height 40+/_0.5mm. A non-porous base plate is provided. The split mould is provided with a suitable clamping ring.PROCEDURE

1. Take 300 g of cement and place it in the enameled tray.

2. Mix about 30% water by weight of dry cement thoroughly to get a cement

paste. Total time taken to obtain thoroughly mixed water cement paste i.e.

“Gauging time” should not be more than 3 to 5 minutes.

3. Fill the vicat mould, resting upon a glass plate, with this cement paste.

4. After filling the mould completely, smoothen the surface of the paste, making

it level with top of the mould.

5. Place the whole assembly(i.e. mould + cement paste + glass plate) under the

rod bearing plunger.

6. Lower the plunger gently so as to touch the surface of the test block and

quickly release the plunger allowing it to sink into the paste.

7. Measure the depth of penetration and record it.

8. Prepare trial pastes with varying percentages of water content and follow the

steps (2 to 7) as described above, until the depth of penetration becomes 33

to 35 mm.

CEM 52.5 N AND R

Initial Setting Time

Initial setting time is that time period between the time water is added to cement and time at which 1 mm square section needle fails to penetrate the cement paste, placed in the Vicat’s mould 5 mm to 7 mm from the bottom of the mould.

Place the test block confined in the mould and resting on the non-porous plate, under the rod bearing the needle.

Lower the needle gently until it comes in contact with the surface of test block and quick release, allowing it to penetrate into the test block.

In the beginning the needle completely pierces the test block. Repeat this procedure i.e. quickly releasing the needle after every 2 minutes till the needle fails to pierce the block for about 5 mm measured from the bottom of the mould.

Final Setting Time

Final setting time is that time period between the time water is added to cement and the time at which 1 mm needle makes an impression on the paste in the mould but 5 mm attachment does not make any impression.

For determining the final setting time, replace the needle of the Vicat’s apparatus by the needle with an annular attachment.

The cement is considered finally set when upon applying the final setting needle gently to the surface of the test block; the needle makes an impression thereon, while the attachment fails to do so. Record this time 

OBSERVATIONS AND CALCULATIONSWeight of cement taken (g) = __300__g_____Initial percentage of water added to cement = _______90 g___Quantity of water added to cement =___30%____     Standard Consistency= (Quantity of water for 5-7 mm penetration/Weight of cement) X 100 POINTS TO BE NOTED1. The time of gauging should not be less than 3 minutes and not more than 5 minutes. Gauging time is the time elapsing from the time of adding water to the dry cement until commencing to fill the mould.2. The test should be conducted at room temperature 27oC +/- 2oC3. There should be no vibration on the working table.4. The plunger should be cleaned during every repetition. RESULTPercentage of water content for standard consistency = %