The compressive test is done on cement, when it is used as mortar and concrete. The mixture of cement and sand in pre defined ratios and the strength of the mortar depend on this ratio. The compressive strength of the mortar depends on the strength and weakness of the mortar. If mortar is weak then the compressive strength of the mortar is also weak. If mortar is strong, then the compressive strength of the mortar will be high.
The mixture of cement and sand in water is generally weak in tension but it is strong in compression when it is subjected to tensile tension with iron rods. The mortar is used for plastering and brick masonry. The first case gives mortar heavy load in form of construction on it by placing bricks on mortar .that is why, it is important to know the strength of the mortar. For testing the compressive strength of the mortar, the mixture of cement and sand is prepared for testing after certain period of curing. The strength of the mortar will depend on the quality of the cement, the gradation of sand used in mixture and the water –cement ratio.
The above mixture Compressive strength testing machine supplier should be according to the ASTM standard to have the required compressive strength of the mortar. If the mixture is not based on the ASTM standard then the strength of the mortar is not up to mark
The ASTM standards are provided for different ratios of the mixture of sand, cement and water. The test value is taken when the mortar is removed from the curing.
Procedure before testing
First, the mixture of sand and cement is made in ratio of 1; 3. That means one part cement and three part sand. The amount of the water to be used in this ratio has to depend on the ASTM standard. The water has to be 10 % of the total weight. The sand and cement is mixed first and the water is added to make the paste
Then one inch cube mould is taken and paste in put into it and pressed with round ended rod. The mixture is tempered at least 25 times. Then next one third portion of the cube mould is filled and again the mixture is tempered. This way at least 6 cubes are filled with mixture. These cubes are kept in open for one day and then three are kept for curing and three are kept in water. Then these cubes Cement testing equipment manufacturer in Delhi are taken out and put under tremendous load to test their strength.