The following important tests are carried out for normal setting of Portland Cement:
1.Fineness Test
This test is conducted to check the proper grinding of cement. The fineness of cement is tested either by sieve method or air permeability method.
The percentage of residue left after sieving good Portland cement in 90 micron IS (Indian standard ) sieve should not exceed 10%.
A good Portland cement should not have specific surface less than 2250 sq cm/g of cement, if found by air permeability method.
2.Consistency Test.
This test is conducted to determine the percentage of water required for preparing cement pastes of standard consistency. The consistency test is performed with the help of Vicat's apparatus which determines the initial and final setting time and normal consistency of cement.
3.Soundness Test:
This test is carried out to detect the pressure of uncombined lime and magnesia in cement which causes the expansion of cement. The soundness of cement is tested with Le Chatelier apparatus. According to Indian standard specifications, the expansion should not exceed 10mm for any type of Portland cement .
4.Tensile strength Test:
This test is carried out on standard briquettes made of a good Portland cement and standard sand mortar (in 1:3 ratio) to determine the tensile strength of cement.
The Average tensile strength after 3 and 7 days of curing should not less than 2 N/ sq mm and 2.5 N/sq mm respectively.
5.Compressive strength test:
This test is carried out on standard cubes of a good Portland cement and standard mortar (in 1:3 ratio) to determine the compressive strength of cement. According to Indian standard specifications, the average compressive strength for three cubes should not be less than 11.5 N/sq mm and 17.5N/sq mm after 3 and 7 days of curing respectively.
This test is conducted to check the proper grinding of cement. The fineness of cement is tested either by sieve method or air permeability method.
The percentage of residue left after sieving good Portland cement in 90 micron IS (Indian standard ) sieve should not exceed 10%.
A good Portland cement should not have specific surface less than 2250 sq cm/g of cement, if found by air permeability method.
2.Consistency Test.
This test is conducted to determine the percentage of water required for preparing cement pastes of standard consistency. The consistency test is performed with the help of Vicat's apparatus which determines the initial and final setting time and normal consistency of cement.
3.Soundness Test:
This test is carried out to detect the pressure of uncombined lime and magnesia in cement which causes the expansion of cement. The soundness of cement is tested with Le Chatelier apparatus. According to Indian standard specifications, the expansion should not exceed 10mm for any type of Portland cement .
4.Tensile strength Test:
This test is carried out on standard briquettes made of a good Portland cement and standard sand mortar (in 1:3 ratio) to determine the tensile strength of cement.
The Average tensile strength after 3 and 7 days of curing should not less than 2 N/ sq mm and 2.5 N/sq mm respectively.
5.Compressive strength test:
This test is carried out on standard cubes of a good Portland cement and standard mortar (in 1:3 ratio) to determine the compressive strength of cement. According to Indian standard specifications, the average compressive strength for three cubes should not be less than 11.5 N/sq mm and 17.5N/sq mm after 3 and 7 days of curing respectively.
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ReplyDeleteI think that tensile strength test is widely used in different industry, such as textile, it is also an important factor for us to make a decision that if we wanna buy it.
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