Consistency test of cement by Vicat apparatus is required to get percentage of minimum required water content on which the Vicat plunger penetrates 5 to 7 mm in cement paste from the bottom of the Vicat mould.
Consistency Test of Cement with Vicat’s Apparatus
For the consistency test of cement, we should confirm that what quantity of water is being mixed with cement for consistency test of cement, it’s sufficient or not for the reaction of cement ingredients like Calcium oxide CaO, Silicon dioxide SiO2, aluminum oxide Al2O3, etc.
Consistency Test of Cement IS Code
For determination of consistency test of cement or test procedure of standard consistency test of cement we follow IS 4031 part 4.
Apparatus and Tools Required for Cement Consistency Test
- Vicat apparatus ( it shall confirm IS 5513-1976 revised in 1996)
What secret in IS 5513-1996
Just take a look, I got this.
It’s all about dimensions of Vicat apparatus components like a plunger, movable rod, graduated scale, Vicat mould and it’s needles.
So now we assume that all doubts are cleared about dimensions of Vicat apparatus components.
- Two numbers of Trowel ( for mixing cement and water ).
- One non-porous plate on which cement and water shall be mixed.
- Weighing balance with at least 0.1 gm accuracy because of permissible variation on 300 gm is +/- 0.3 gm, and for 500 gm is +/- 0.35.
- Hand gloves for your safety.
Precautions before proceeding Consistency test
- Vicat apparatus and it’s components shall be clean, mainly needle.
- De-shuttering agent ( lubricant or grease ) shall be applied the inner surface of Vicat mould.
- Non-porous plate and trowels shall be clean before the test, we should not use trowels and non-porous plate in wet condition, this moisture may affect on the test result.
- The temperature of the room where cement consistency test is going to be done shall be 27 +/- 2-degree Centigrade, which means between 25 to 29.
- Like temperature, Humidity is also an important factor for the consistency test of cement, humidity shall be 65 +/- 5 percent, which means between 60 to 70.
- Ensure zero on a graduated scale with empty Vicat mold and base plate.
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Procedure of Consistency Test of Cement
Percentage of Water for Normal Consistency test of Cement
- Take 400 gram of cement and 25 percent water of cement weight if you are new to this cement,
Means if you are testing consistency this cement first time and you do not know about its property, so you may start with 25 percent water because any cement consistency comes between 25 to 35 percent.
- Water increment will be 0.5 percent like first 25.0 %, 25.5 %, 26.0 %, 26.5 % …….
- Mixing time is 3 to 5 minutes, it will start when you adding water in cement and finish when getting the penetration on the graduated scale.( important )
- Start the stopwatch and add water in cement simultaneously.
- Mix properly by using both trowels, it is very important.
- After mixing well, Vicat mould shall be filled by that cement paste by slightly shaking or slightly struck the mould. Be ensure that no voids is in the paste.
- After filling the mould with cement paste, Vicat mould with paste shall be placed in Vicat apparatus.
- Fix consistency needle in Vicat apparatus before starting the test.
- Lower the Vicat plunger slowly until the consistency needle bottom point touches the cement paste top surface filled in Vicat mould.
- Release the plunger quickly, let it sink in the paste, when it stops sinking ( nearly 3 to 4 seconds ) note down the reading from the graduated scale.
- Increase water content 0.5 percent until you get 5 to 7 mm reading on a graduated scale.
- Note down that water content on which you got penetration between 5 to 7 mm.
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Consistency of Cement Value
On which water content we get penetration between 5 to 7 mm in Vicat’s apparatus reading scale, that water content percentage is the consistency of cement value.
If we added 116 grams of water in 400 grams of cement for consistency test,
so the consistency of cement value = (116/400)*100 = 29%
Range of Values of Standard Consistency Test of Cement
Standard Consistency of Cement in Percentage
The range of values of the standard consistency test of cement is 25% to 35%.
Cement Consistency Limits
Consistency limits of cement are 5 mm to 7 mm.
Report & Calculation of Consistency test of cement
- no. cement (gm) water (%) penetration (mm)
- 400.0 27.0 12
- 400.0 27.5 8
- 400.0 28.0 6
Standard consistency – 28.0 %
Our Practical Video of Consistency Test of Cement
Viva Questions on Initial and Final Setting time of Cement
Q.1 What is consistency of cement?
Ans. The consistency of cement is the minimum required water percentage on which the Vicat plunger penetrates 5 to 7 mm in cement paste from the bottom of the Vicat mould.
Q.2 What is dia and length of the needle to check the consistency of cement?
Ans. The dia and length of the needle of the consistency test are 10.0 mm and 50 mm.
Q.3 What is the IS code for consistency test procedure?
Ans. IS 4031 part 4.
Q.4 What is the mixing time of cement and water for consistency test?
Ans. 3 to 5 minutes.
Q.5 What is the IS code for Vicat apparatus?
Ans. The IS code for Vicat apparatus is IS 5513. In this IS code you can read all about Vicat apparatus.
Any other question? Just ask in comment. We are waiting to reply.
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Hope, Now you clear about “consistency test of cement” procedure.
While flow is not normally included in the specifications for hydraulic cement, it is commonly used in standard tests where the mortar must have a water content that provides a certain level of flow.
Cement paste acts as a separator for aggregates in the mortar, and a lack of mortar results in a mixture with limited fluidity.
A cement paste or mortar mix is placed in a mold of defined volume and dimensions and the mold is placed on top and in the middle of a flow table apparatus where the sample is molded and compacted.
The consistency of a mixture plays an important role in the performance of the mixture as it is cast through rebars within a mold and for the time required for the mortar or concrete to set.
The consistency test is performed to estimate the amount of water needed to form a normal consistency paste, defined as the percentage of water required by the cement paste.
When water is added to the cement, the resulting paste begins to harden and gain compressive strength.
When cement is mixed with water, it is stiff and forms a sticky paste. Over time, the plasticity gradually disappears and the paste turns into a solid mass.
The phenomenon by which the cement paste changes from a plastic state to a solid-state is known as the setting of cement. Time begins with the addition of water to the cement.
Half fill the dashpot with a suitable viscosity oil and unscrew the cap. Put 400 g of cement in a pan and a weighed amount of water in a beaker.
Hold the Vicat mold on a non-porous plate and fill in the cement paste. After filling the mold completely, gently shake it to expel the air.
Little about Cement
Cement is a binder, a substance used in structures that harden and adhere to other materials to connect them.
There are two main types of cement: Geopolymerzement and Portland cement. Cement is rarely used alone, but to bind sand and gravel (aggregates).
Cement mixed with fine aggregate forms a mortar or with sand and concrete gravel.
Concrete in its simplest form is a mixture of Portland cement, sand, coarse aggregate and water.
Currently, most concrete mixes contain additional cement materials that form part of the cement component in concrete.
Can be further processed for use in concrete or not.
Some of these materials are called pozzolans, which in themselves do not have to cement properties, but when used with Portland cement, they react to form cement compounds.
Complementary cement materials can be used fresh and hardened to improve concrete properties.
Concrete mixes with a high Portland cement content tend to crack and increase heat.
Additional cement materials, such as fly ash, slag, and silica dust, enable the concrete industry to use hundreds of millions of tonnes of by-products that would otherwise be dumped as waste.
In addition, their use reduces the consumption of Portland cement per unit volume of concrete.
Essentially released Ch crystals are responsible for creating a passive layer around the reinforcement of reinforced concrete elements.
However, when highly active pozzolanic materials are used in cement-based mixtures, they remove CH from the system and accelerate the normal hydration of Portland cement.
However, this application has largely disappeared due to increasing strength, more accurate milling of Portland cement and the interaction of chemical additives.
When considering the physical chemistry of admixture interactions, their chemistry cannot be inferred from the hydration of Portland cement and even other types of cement, such as cement, for example.
B.based on calcium aluminates for separation. Active dopants react with a dissolved cement component, such as lime, to form a derivative.
These events do not affect the active ingredient of the mixture.
Hesspozz is the same natural, balanced pumice stone that the Romans used, but it was carefully refined, resulting in a puzzle piece that significantly improves concrete chemistry and ensures consistent casting performance.
Over one hundred years ago, pumice stone was identified as the main component of impressively durable and timeless Roman concrete.
Pumice stone HessPozz can compete well with other complementary cement materials (SCM) available on the market, including fly ash, silica fumes, and metakaolin.
The Roman word opus caementicium describes a wall that resembles modern concrete and is made of gravel with quick lime as a binder.
Volcanic ash and powdered brick additives added to quicklime to produce a hydraulic binder were later called cement, resin, cement, and cement.
At present, organic polymers are sometimes used as cement in concrete.
Masonry cement are used for mortar and stucco work and must not be used in concrete.
These are usually complex proprietary formulations containing Portland clinker and a number of other ingredients, including limestone, hydrated lime, air entrainers, retarders, hydrophobic agents and dyes.
They were developed to give machine mortars that enable fast and consistent work in the wall.
Expansion cements in addition to Portland clinker contain expansion clinker (usually aluminate sulfate clinker) and are designed to counteract the effects of shrinkage during drying usually associated with hydraulic cement.
Some standards allow pigments to be added to produce colored Portland cement. Very finely ground cement are cements mixed with sand or slag or other pozzolanic minerals that are very finely ground together.
Hydration products that produce strength are essentially the same as those in Portland cement.
They produce strength by creating ettringite with an increase in strength similar to free Portland cement.
Calcium aluminate cements are hydraulic cements made mainly of limestone and bauxite.
Rather, it settles on drying and reacts with carbon dioxide in the air. Hydraulic cements (e.g. Portland cement) harden and become sticky as a result of a chemical reaction between dry components and water.
Mechanical properties are holistic indicators of the microstructural evolution of cement matrices in response to hydration.
In addition to chemical effects, the values are mainly controlled by physical parameters such as porosity and compactness. shows the development of compressive strength of samples estimated after 28 days of curing and containing increasing amounts of red sludge that replaced Portland cement in the mixture.
As expected, the mechanical strength decreased as cement exchange increased, as red sludge has limited hydraulic properties.
About 3 in red mud can be crucial to increase cement activity. In addition, other researchers13 found that the hydration reaction of Portland cement is favored by the strongly alkaline environment characteristic of red mud.
About half of the Portland cement used in construction is used for masonry and plaster.
In these products, the maximum potential strength that cement develops is never fully utilized.
Portland cement is by far the most commonly used type of cement in the world.
Concrete is composed of aggregates (gravel and sand), cement and water.
Concrete can be poured as a building material in almost any shape and after hardening can be a load-bearing element.