CTN PRESS

CTN PRESS

NEWS & BLOGS EXCLUCIVELY FOR INFORMATION TO ENGINEERS & VALUERS COMMUNITY

DIFFERENT PHYSICAL TEST ON CEMENT

1. Fineness Test

The fineness of cement is a measure of cement particle size and is denoted as terms of the specific surface area of cement. The Test is done by sieving cement samples through a standard IS sieve.

The weight cement particle whose size is greater than 90 microns is determined and the percentage of the retained particle are calculated. This is known as the Fineness of cement.

2. Normal Consistency Test

Normal Consistency test of cement is conducted to determine the quantity of water required to produce a cement paste of standard or normal consistency for use in other tests.

3. Initial and Final Setting Time Test

When cement is mixed with water is stiff and sticky paste is formed. This cement paste remains plastic for a short period. As the time lapses, the plasticity gradually disappears and the paste changes into a solid mass.

The phenomenon by virtue of which the cement paste changes from a plastic state to a solid-state is known as the setting of cement. The time to reach this stage is known as setting time.

4. Soundness Test

Soundness test of cement is performed to identify the presence of excess free lime and magnesia in the cement. This test is performed with the help of  Le-Chatelier apparatus.

5. Compressive Strength Test

To perform this test 200 gm of cement and 600 gm of standard sand are taken and mixed thoroughly. To this, water is added @ P/4 + 3% when standard sand is used and @ P/4 + 3.5 % when ordinary sand is used. Where P is the percentage of water required for a paste of normal consistency.

It is mixed thoroughly to an even colour. The cube mould of size 7.06 cm is placed on a non-porous base plate and is oiled inside. The above mortar is put into the cube mould and is compacted for two minutes by the vibration machine. The top surface is smoothened off by trowel.

6. Chemical Composition Test.

As per IS: 269 – 1975 the chemical requirements of ordinary cement should be as follows

  1. The ratio of the percentage of alumina to that of iron oxide should not be less than 0.66
  2. The ratio of the percentage of lime to those of alumina, iron oxide and silica calculated with the following formula should not be less than 0.66 and it should not be greater than 1.02.

7. The Heat of Hydration Test

The heat of hydration is defined as the chemical reaction between cement and water. during hydration of cement, sufficient heat is generated. The process of heat generation is quite rapid in the initial stage of the setting but its rate diminishes with the passage of time.

8. Tensile Strength Test

For evaluate the tensile strength of the cement, at first, six numbers of standard briquettes are made from cement mortar. All these briquettes are broken after 1 day, 3 days and 7 days of curing.

 

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