![]() Define cement plaster |Methods and Measurement of cement plaster The maximum total quantity of aggregate per 50 Kg of cement shall not exceed 450 Kg except when otherwise specifically approved by Engineer. It shall be very clearly understood that whenever the class of concrete such as M 20 is specified it shall be the engineer responsibility to ensure that minimum crushing strength as per the for the respective class of concrete. Time and strength gain: time and strength of cement relationship are non linear.ġ) 1 day of curing time cement gain its strength about 16% of total strengthĢ) 3 days of curing time cement gain its strength about 40% of total strengthģ) 7 days of curing time cement gain its strength about 65% of total strengthĤ) 14 days of curing time cement gain its strength about 90% of total strengthĥ) 28 days of curing time cement gain its strength about 99% of total strengthĦ) 3 months of time cement gain its strength about 110% of total strengthħ) 6 months of time cement gain its strength about 115% of total strengthĨ) 1 year of time cement gain its strength about 120% of total strength.Compressive strength of concrete cube testĪll concrete in the works shall be of design mix as defined in IS 456: 2000, unless it is a nominal mix concrete.It should be assumed that two types of cement meeting the same minimum requirements will produce the same strength of mortar or concrete without modification of mix proportions. Strength tests are not made on a neat cement paste because of difficulties of moulding and testing with a consequent large variability of test results.Ĭompressive strength is influenced by the cement type, or more precisely, the compound composition and fineness of cement. Place the test cube on the platform of a compressive testing machine without any packing between the cube and the plates of the testing machine.Īpply the load steadily and uniformly, starting from zero at a rate of 35 N/mm2/minute.Ĭement compressive = load/ cross sectional area F= p/AĪ=Cross sectional area (Calculated from the mean dimensions) (mm2)ģ)The temperature and humidity must be accurately controlledĤ) Increase the load gradually during testing.ĥ) The cubes should be tested immediately after taking out of water and not allowed to dry until they fail under testing.Ħ) The gauging time should be strictly observed.ħ) The cubes should be tested on their sides and not on their faces. The cube be taken out of the water only at the time of testing. Remove the mould from the machine and keep it in a place with temp of 27☒☌ and relative humidity of 90% for 24 hours.Īt the end of 24 hrs remove the cube from the mould and immediately submerge in fresh clean water. Place the thoroughly cleaned and oiled (on interior face) mould on the vibrating machine and hold it in position by clamps provided on the machine for the purpose.įill the mould with entire quantity of mortar using a suitable hopper attached to the top of the mould for facility of filling and vibrate it for 2 minutes at a specified speed of 12000±400 per minute to achieve full compaction. Take 200 g of cement and 600 g of standard sand (1:3) and mix them dry thoroughly.Īdd cement consistency is 2 for water (where P is % of water required for preparing paste of standard consistency) to the dry mix of cement and sand and mix thoroughly for a minimum of 2 minutes by vibrator at the rate of 12000+- 400 per minute to obtain a mix of uniform colour. ![]() Test procedure for compressive strength of cement and other apparatus is used for cube test isĮnamel tray, Trowel, Poking rod,Cement MouldĢ) environmental condition: the temperature should be 29℃ or 25℃ are represented as temperature 27 ± 2☌, humidity should be 65 ± 5%ģ) cement sand ratio:_ cement sand ratio for preparing mortar is 1:3 in which one part is cement and 3 part is sand.Vibration machine Should be as per IS:10080._ Compressive strength of cement testġ) For the cube test we require following appartus ![]()
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