#Portland cement specific gravity lab free

The cement that adheres to the inside of the flask should be stirred to form a heterogeneous mixture of cement and the liquid.The inside of Le-Chatelier’s flask should be dry before adding kerosene or naphtha into it.

#Portland cement specific gravity lab free

The liquid to be added to the flask (kerosene or naphtha) should be free from water.

If the obtained value of specific gravity differs greatly from the standard or refernce value (given that the test is performed under standard conditions), the cement contains impurities.

The standard specific gravity of cement is 3.15. Additionally, if the two test results differ by more than 0.03, a retest is mandatory. Note: At least two tests must be carried out and their average value must be reported. Specific Gravity of cement = W c / W w Method IIĭensity of water at 4☌ = ρ w = 1000 g/cm 3 Weight of water having volume V (g) = W w = Volume of water taken in the measuring cylinder = V = Compare the specific gravity value with the standard specific gravity of Ordinary Portland Cement i.e., 3.15.ĭifference in the level of flask = Volume of cement = V = V f – V i Method I.Calculate the specific gravity of cement using the known water density at 4☌ as.Determine the density of cement using its known weight and displaced volume as.Calculate the specific gravity of cement as follows.This is termed as the weight of an equal volume of water, or the weight of displaced volume. Determine the weight of this known volume of water.In order to determine the specific gravity of cement, take water in a measuring flask equal to the volume of cement determined previously.The specific gravity of cement can then be determined in two ways. The differential volume in the flask in actuality, is the volume of cement, the weight of which is already known (64gm).Calculate the change in the level of liquid in the flask by taking the difference of initial and final readings.Record the final reading on the flask after placing it in the water bath to prevent temperature fluctuations from affecting the test results. After the addition of cement, the level of water in the flask will rise.Whirl the flask horizontally to remove air from the cement.Add the weighed quantity of cement into the flask carefully in increments at the same temperature as that of the liquid present in it.Weight about 64g of cement of a weighing balance.Fill the Le-Chatelier’s flask with kerosene oil or naphtha between 0 and 1mL graduations present on the flask using a glass funnel.

The Le-Chatelier’s flask should be immersed in a water bath sporadically to ensure the temperature variation does not exceed 0.2☌ at the time of recording the readings. Water bath, to regulate and control the test temperature.Measuring cylinders, to measure the exact amount of water.Water, as a reference liquid for specific gravity determination.Weighing balance, to weigh the required cement quantity and water.Glass funnel, to transfer kerosene oil into the Le-Chatelier’s flask.Kerosene oil or naphtha, having a density greater than 0.73 g/mL at 23☌.Le-Chatelier’s flask, circular in cross-section and made up of transparent glass having marked graduations.This can possibly affect the binding property of cement, its workability, and strength. In mix design procedures, this is of paramount importance since a higher value of specific gravity than that generally accepted signifies that it has more moisture content. The specific gravity of cement is an important parameter that informs about its density. Significance of determination of specific gravity of cement Therefore, kerosene is used as a replacement for water. This is because when water is added to powdered cement, the hydration process commences. The specific gravity of Ordinary Portland Cement (OPC) is 3.15.įor the determination of specific gravity, water is not used. The denominator in the above expression indicates the weight of the liquid displaced due to addition of cement into it. The specific gravity of cement is the ratio of the weight of cement to the weight of volume displaced by it. The specific gravity of a substance varies with temperature. It is a dimensionless number and is mathematically calculated as, The specific gravity (also called the relative density) of a substance is the ratio of its density to the density of water at 4☌. This test aims at determining the specific gravity or relative density of cement which can then be compared with the standard or reference value to hint out the possible impurities in the cement. Significance of determination of specific gravity of cement.