Weigh a clean and dry Le Chatelier Flask or Specific Gravity Bottle with its stopper (W1). Place a sample of cement upto half of the flask (about 50 gm) and weight with its stopper (W2). Add kerosene (polar liquid) to cement in flask till it is about half full. Mix thoroughly with glass rod to remove entrapped air.
What is specific gravity of cement definition?
The specific gravity of cement is defined as the mass of cement of a specified volume to the mass of water of the same volume of cement. It can also be defined as the density of cement to the density of water for the same volume. The specific gravity of cement ranges from 3.1 to 3.16 g/cc.
What is the acceptable specific gravity of cement?
Specific gravity is normally used in mixture proportioning calculations. The specific gravity of portland cement is generally around 3.15 while the specific gravity of portland-blast-furnace-slag and portland- pozzolan cements may have specific gravities near 2.90 (PCA, 1988 ).
Why specific gravity test is done?
Why the Test is Performed – This test helps evaluate your body’s water balance and urine concentration.
What are the 3 types of gravity?
How many types of gravity are there? Answer Verified
Hint: In order to solve this question, we are going to firstly define the gravity and explain it mathematically then, the equation for gravitational force is given and it is discussed about the types of gravity and the reason for the existence of those types and the properties of gravitational forces. Formula used: The gravitational force is given by the formula: Complete step-by-step solution:
\Where, \is the Gravitational constant, \and \are the masses of the two bodies and \is the distance between the two masses.Gravity is the gravitational force which is the force of attraction between two bodies that depends on the product of the masses of the bodies and is inversely proportional to the square of the distance between the bodies.
The gravitational force is given by the formula:\Where, \is the Gravitational constant, \and \are the masses of the two bodies and \is the distance between the two masses.There is only one type of gravity. There are no other types of gravity present in nature. This means there is only one type of gravitational force that pulls the two bodies together based on their masses and the distance between their centers.
Gravity is a type of central force and is the weakest force known in nature. It follows the inverse square law. It is a universal attractive force and there are no other types in which it is classified. Note: It is to be noted that with the advancement in science and research, it may be possible that there are some types of gravitational waves called LIGO but it hasn’t formed a theory yet.
What are the other methods of measuring specific gravity?
Methods of Determining Specific Gravity – A number of experimental methods for determining the specific gravities of solids, liquids, and gases have been devised. A solid is weighed first in air, then while immersed in water; the difference in the two weights, according to Archimedes’ principle, is the weight of the water displaced by the volume of the solid.
If the solid is less dense than water, some means must be adopted to fully submerge it, e.g., a system of pulleys or a sinker of known mass and volume. The specific gravity of the solid is the ratio of its weight in air to the difference between its weight in air and its weight immersed in water. Two methods are commonly used for determining the specific gravities of liquids.
One method uses the hydrometer, an instrument that gives a specific gravity reading directly. A second method, called the bottle method, uses a specific-gravity bottle, i.e., a flask made to hold a known volume of liquid at a specified temperature (usually 20°C).
The bottle is weighed, filled with the liquid whose specific gravity is to be found, and weighed again. The difference in weights is divided by the weight of an equal volume of water to give the specific gravity of the liquid. For gases a method essentially the same as the bottle method for liquids is used.
Specific gravities of gases are usually converted mathematically to their value at standard temperature and pressure (see STP ).
Why specific gravity of cement is required?
Significance or Importance of Specific Gravity of Cement Specific gravity of a material is defined as the ratio between weight of a given volume of material and weight of an equal volume of water. Therefore, specific gravity of cement is the ratio of weight of a given volume of cement with weight of an equal volume of water at a specified temperature. Hi friends, you are welcomed in the world of Civil Allied Gyan. “Read here significance or Importance of specific gravity of cement,” Also read:
Density of the cement and other material is one of the vital parameter, which determines the design of the concrete. Since concrete mix proposition is done based on the weigh batching not on volumetric so density is most important factor. The specific gravity of cement is important because it is one of the factor which determines the density of the cement. As we know that, the cement may contain lots of moisture content if it is exposed to various conditions and humidity. We all know that water cement ratio is an important factor of cement paste. It is directly proportional to workability and strength of a bonding. If the cement has already more moisture content in it then, the value of water-cement ratio will actually affect the workability and strength of cement paste rather than increasing it. If the specific gravity of cement is more than 3.19 then, the cement is either not minced finely as per the industry standard or it has more moisture (or water) content, which will affect the mix and bonding. This is why you find many chunks while mixing old stock cement for concrete. Every material contains solid particles and pores, which may contain moisture content due to extreme weather conditions. Which may rise the specific gravity of material. Ones the specific gravity of cement reaches 3.19 then pores are filled with moisture, the chemical reaction take place. This process is called hydration. Moisture is the biggest enemy of cement. Once cement hydrated with water, it becomes useless. This is the reason that is why many lumps are formed in the old stock of cement due to moisture content. As per Indian Standard Specification, cement is tested for specific gravity if it is older than 3 months. Generally, a nominal mix is prepared with the cement of specific gravity value 3.15. If there is any change in this value, it will affect the mix design. It may increase the water-cement ratio, which will affect the workability and strength of concrete.
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Significance or Importance of Specific Gravity of Cement