Compressive Strength Test of Cement

Compressive Strength test of cement is very important test for using the cement, and design the any constructions like; bridges , multi storey building etc,

Compressive strength test procedure :-

Compressive Strength test of cement are not made on neat cement paste because of difficulties of excessive shrinkage and subsequent cracking of neat cement. Strength of cement is indirectly found on cement sand mortar in specific proportions. 
          The standard sand ( Ennore sand found in Kerla ) is used for finding the strength of cement. It shall conform to IS 650-1991. Take 555 gms of standard sand (Ennore sand), 185 gms of cement (i.e., ratio of cement to sandis 1:3) in a non-porous enamel tray and mix them with a trowel for oneminute, then add water of quantity P/4 + 3.0 percent of combined weight of cement and sand and mix the three ingredients thoroughly until the mixture is of uniform colour. 

• What is surveying? | Types | Classification |
• Types of Cement , Properties and uses of construction
• Fineness Test of Cement

                The time of mixing should not be less than 3 minutes nor more than 4 minutes. Immediately after mixing, the mortar is filled into a cube mould of size 70.6 mm. The area of the face of the cube will be equal to 50 sq cm. Compact the mortar either by hand compaction in a standard specified manner or on the vibrating equipment (12000 RPM) for 2 minutes.

Keep the compacted cube in the mould at a temperature of 27°C ± 2°C and at least 90 percent relative humidity for 24 hours. Where the facility of standard temperature and humidity room is not available, the cube may be kept under wet gunny bag to simulate 90 percent relative humidity. After 24 hours the cubes are removed from the mould and immersed in clean fresh water until taken out for testing.

Three cubes are tested for compressive strength test at the periods 

The periods being reckoned from the completion of vibration. The compressive strength shall be the average of the strengths of the three cubes for each period respectively. The strength requirements for various types of cement. An average of free sample having the deviation of +-15 % in straingth is consdered as a test result .