Explanation of cement markings and application features

A unique building material - cement, in accordance with its intended purpose, is produced in a huge variety of types, types and subtypes. At the same time, the purpose, composition and other basic consumer characteristics are indicated by the marking of cement.

The marking is printed on the surface of the packaging (paper bag or big bag) or indicated in the accompanying documentation for a batch of cement supplied in bulk.

The marking of cement in bags, big bags and in bulk must comply with GOST requirements, otherwise the buyer of the material purchases fake cement with all the ensuing “troubles”.

Cement marking in the Russian Federation

In the Russian Federation, new cement markings compiled and applied in accordance with the requirements of the regulatory document GOST 31108-2003 “General Construction Cements”, which came into force on September 1, 2004, are considered “legal”. At the same time, in old documents and on the Internet you can find old markings of cements for general construction purposes in accordance with GOST 10178-85.

In this regard, it can be difficult for a non-specialist to figure out what building material to order for the independent construction of a building or concrete structure. Therefore, within the framework of this article, the new marking of cement GOST 31108-2003 and the old version - designation according to GOST 10178-85 will be considered.

Specifications

The M500 cement grade demonstrates high performance characteristics. The mixture is especially popular due to its strength, reliability and durability, as well as versatility.

Main properties of Portland cement M500:

• Start of setting – 45 minutes after mixing
• Complete hardening and strength gain - within 28 days
• Frost resistance – about 70 freeze/thaw cycles
• Bending load – up to 6.3 MPa (63 atmospheres)
• Grinding fineness – 92%
• Hygroscopic expansion – maximum 10 millimeters
• Compressive strength – 59.9 MPa (591 atmospheres)
• The shelf life of the dry mixture is about 1 year in original, undamaged packaging (despite the fact that the packages usually indicate M500 for 12 months, after 3-6 months it gradually loses its properties)
• Radioactivity – up to 370 BC/kg (class 1)
• Density – up to 3200 kg/m3

Density

Density is an informative indicator that is responsible for the quality of the binder. It is the density that affects the reliability and strength of the hardened stone. The higher the bulk density indicator of Portland cement (PC) 500, the lower the porosity of the monolith will be and the worse it will absorb water and collapse under frost and various loads.

The bulk density of M500 cement can vary between 1100-1600 kg/m3. In calculations, an indicator of 1300 kg/m3 is usually used. The true density of the material is 3200 kg/m3.

Supplements

Various additives are introduced into Portland 500 cement, designed to improve certain of its properties and perform other tasks.

Main types of cement additives:

• To regulate properties - affect strength, setting time, plasticity, water absorption.
• Material – influence the processes of hydration and hardening. These can be active mineral additives or fillers.
• Technological - influence the grinding process, which can in a certain way affect the characteristics of the material, but is not at all necessary.

The volume of additives may vary, as indicated by the labeling. D0 is cement without additives, D5 or D20, for example, is cement that contains 5% and 20% of different substances, respectively. All additives are designed to improve the characteristics of the binder, to one degree or another.

Consumption rates

Portland cement M500 is supplied in bags of 25 kg, 50 kg (more in demand). And the question of how much binder is needed to prepare the solution is relevant for all craftsmen. Consumption rates depend on what kind of concrete needs to be prepared and why. Masonry and plaster mixtures are made from cement and sand in a ratio of 1:3, 1:2.

As a rule, the following components are used to fill and create durable structures: clean sand (without clay, silt, debris, small crushed stone), crushed stone with frost resistance F-65 and strength minimum M1000, Portland cement M500.

M500 for different solutions:

• Concrete M200 – 250 kilograms
• M250 – 300 kilograms
• M300 – 350 kilograms
• M350 – 400 kilograms
• M400 – 450 kilograms

It is almost impossible to prepare concrete with a strength of M300 or higher at home, since it requires thorough mixing, which is extremely difficult to achieve without the use of technological equipment.

Packing and packing

Cement is produced and supplied in any volume. Standard packaging of M500 is in bags of 25, 50 kg (you can find M500 40 kg, but less often). After production, the cement is distributed into sealed towers, where a powerful ventilation system with a low level of air humidity is installed. Here the binder can be stored for up to 14 days.

Then the Portland cement is packaged in paper bags. The gross weight of the bag is no more than 51 kilograms. The bags must be made of several layers of polyethylene to prevent moisture from penetrating the powder. The packaging indicates the packaging date and markings with basic symbols that provide information about the material.

Under production conditions, the M500 should only be stored in its original container and for no more than a few months. If you plan to store it for a long time, the bags are placed on special pallets and turned over every 2 months.

Storage conditions: normal humidity level, air temperature up to +50 degrees. When in contact with air, cement absorbs moisture from it, which reduces its properties. Also, the binder loses parameters every few months, so the highest quality mortar can be obtained from fresh cement.

Decoding cement grades according to the new GOST 31108-2003

In accordance with the current regulatory document, the designation of a general purpose binder consists of the following “components”:

• Product type. For example: “Portland cement”, “Portland slag cement”, “Composition cement”, etc.
• Type of cement. It is a combination of capital letters and Roman numerals. For ease of work, we summarize the designation and decoding of the type of cement in the following table:

• The designation of the type of additives following the designation of the subtype of the material composition of the product is summarized in the following table:

Also in the marking of cement you can find the letter “H” , which means that the cement was prepared using a standardized clinker composition.

• Strength class: 22.5; 32.5; 42.5; 52.5. Strength marking of cement is the most important indicator for the consumer. This group of numbers identifies the compressive strength of concrete 28 days after mixing. For example, a group of numbers 32.5 corresponds to the old designation of compressive strength 400 kgf/cm2 (Portland cement M400), numbers 42.5 - 500 kgf/cm2 (Portland cement M500), etc.
• Compressive strength when setting cement for two to seven days (except for cement of strength class 22.5) is characterized by the letters N or B, normally hardening and fast-hardening, respectively.
• The regulatory document in accordance with which the product is manufactured is GOST 31108-2003.

Example of marking: Portland cement with the addition of slag TsEM III/V-Sh 42.5B GOST 31108-2003. Explanation of cement marking: Portland cement with additives, subtype B, with the addition of granulated slag, strength class for 28 days 42.5, fast-hardening, meeting the requirements of GOST 31108-2003.

Types of cement grade 400

Binder with strength grade M400 can be produced on the basis of different components; depending on this, the material is divided into several main groups:

1. Portland cement (PC) is the most common type, produced on the basis of calcium silicates (alite). These are metamorphic rocks. It is characterized by medium-term hardening and high technical characteristics.
2. Aluminous cement (GC or VGC) is produced on the basis of aluminum, calcium, iron and silicon oxides in accordance with GOST 969-91. The material is characterized by accelerated setting and hardening. Suitable for urgent construction, including in winter.
3. Magnesia cement (MGC) is a product of grinding clinker with a high magnesium content. The hardened stone is characterized by high wear resistance and density.
4. Pozzolanic cements (PPCs) are made from volcanic rocks that are carefully crushed to a powdery state. Suitable for production are siliceous and aluminous mineral substances, some types of slag and fly ash, which have significant viscosity.
5. Slag Portland cement (SPC) is a binder made from clinker and blast furnace or electrothermophosphorus slag with the amount of the latter not exceeding 20%. This binder is cheaper than the classic one; it is used when it is necessary to equip structures in aggressive environments and mineralized waters.

Cement marking GOST 10178-85

The designation of cements according to this regulatory document is a combination of capital letters and Arabic numerals. In accordance with the requirements of GOST, the designation of cement must consist of the following “components”:

Full or abbreviated name of the product type (see table below).

• A group of numbers indicating the compressive strength of concrete or mortar 28 days after mixing (grade) kgf/cm2: 300, 400, 500, 600.
• A combination of the capital letter “D” with a group of numbers indicating the content of additives as a percentage per unit mass of the product: D0 (additive content 0%), D20 (additive content 20%), etc.
• A capital letter or a group of capital letters indicating the special properties of cement: “B” (fast-hardening), “N” (cement with normalized clinker content), “PL” (cement with plasticizing properties), “GF” (cement with water-repellent properties).
• The regulatory document in accordance with which the product is manufactured is GOST 10178-85.

Example of marking: PC 500-D0-B – GF GOST 10178-85. Explanation: Portland cement, grade M500, fast-hardening, without additives, hydrophobized, manufactured according to GOST 10178-85.

Properties and characteristics of cement

Cement grades reflect the main characteristics necessary for the preparation of high-quality mortars. This material is made from clinker, which makes up the bulk of it. They are made by burning limestone and clay and then grinding them into fine powders. The smaller the fraction of the astringent inorganic component, the faster the mortar hardens. To improve the properties, mineral impurities are added - pyrites, bauxites, tripolis. The main characteristics of the material include:

• Strength is the mechanical load withstood by the sample. The sample contains 25% binder and 75% pure quartz sand. A 10x10x10 cm sample poured into a mold is destroyed to determine the pressure. Cement grades are classified according to the strength of the resulting solution.
• Setting time is the most important parameter affecting the speed of work, especially at low temperatures. To speed up the process, gypsum or other additives are added to the mixture.
• Frost resistance - the number of freezing and thawing cycles - to increase it, wood pitch or sodium abietate is added to the composition.

The use of various additives helps to obtain formulations with specified technical characteristics:

• Quick-setting composition;
• Sulfate-resistant, used in the construction of hydraulic structures;
• Expandable waterproof;
• Compositions with plasticizers for work at low temperatures;
• Facing materials, compositions for finishing premises;
• Standardized cement with specified properties.

Specific gravity of sand-cement mixture

How much one cubic meter of sand-cement mortar will weigh directly depends on the bulk density and mass of the mixture components. Light fillers (perlite, expanded clay, etc.) reduce the mass of the finished solution, heavy fillers, respectively, increase it. In addition, much may depend on the proportion of the components taken and the characteristics of the solution preparation.

The classic composition involves the use of cement as a binder, sand (fine filler), crushed stone (coarse filler), and water. In this case, when there are no additives or light fillers that change the density of the solution, the weight of a cubic meter of the mixture is standard.

• M100 – up to 2494 kg/m3.
• M200 – up to 2432 kg/m3.
• M250 – up to 2348 kg/m3.
• M300 – up to 2389 kg/m3.
• M350 – up to 2502 kg/m3.
• M400 – up to 2376 kg/m3.
• M500 – up to 2980 kg/m3.

M 200

A popular brand for making foundations, floors, pouring floor screeds, and installing building structures. The M200 index means that a frozen monolith from this solution can withstand loads of up to 200 kg/m2 (that is, the brand determines the strength of the stone).

• High level of strength and reliability due to low density (class B25).
• Fast drying.
• Low thermal conductivity.
• Mobility at level P3.
• The ability to work with the mixture at temperatures up to +5 without changing its properties.
• Waterproof –
• Frost resistance – F
• No cracks or deformations during shrinkage.

The proportions for preparing the M200 mixture from M400/M500 cement are indicated above. The specific gravity of the mixture is about 2430 kilograms.

M 300

The standard specific gravity of M300 concrete is 1800-2500 kg/m3. The indicator depends on the density - and, therefore, the type of crushed stone that is included in the composition. The specific gravity of the mixture is also influenced by the method of using the solution and the presence of air cavities in it.

Water resistance corresponds to W5-W6 - this means that concrete at a pressure of 0.5-0.6 MPa (5-6 atmospheres) will not allow water to pass through. The value can be increased through the use of hydrophobic cement and special additives.

The mobility of the composition is at the P4-P5 level and depends on the volume of water in the mixture, the presence/absence of additives in the solution.

M 400

Concrete grade M400 is used where it is necessary to achieve high strength characteristics, resistance to various influences, reliability and durability. Thus, the M400 index indicates that the frozen monolith can withstand a load of 400 kg/cm2, which is quite a lot.

Application of different brands

The scope of application of cement depends on its brand and the characteristics that determine its properties. The main types include:

• M300 is the cheapest brand used in single-story, private construction.
• M400 – applicable for the manufacture of reinforced concrete structures, preparation of standard concrete, plaster mortars, bricklaying, concreting of above-ground and underground structures.
• M500 is used in bridge supports in water or on land, as it provides increased strength, and is used in the construction of communications and structures, and for repair work.
• M600 is intended for the production of high-quality prefabricated structures with high requirements for strength and frost resistance.
• M700 is used for concrete with strength class B35 and above, used in structures with high mechanical stress.

Various brands of Portland cement can change their properties due to additives that increase the setting speed, frost resistance, and pouring at high humidity.

The use of cement depends on its type, composition and properties:

• Portland cement – ​​concrete monoliths, reinforced concrete structures.
• Portland slag cement – ​​monoliths, including underground and underwater.
• Pozzolanic compositions – prefabricated structures, underwater and underground monoliths.
• Alumina - used for repairs and damage repairs due to their high setting speed. With increasing alumina concentration, the heat-resistant properties of the resulting materials increase.
• Gypsum-alumina - used for waterproof concrete, expanding and non-shrinking materials.
• Colored and white materials - used for interior and exterior finishing work.

The correct selection of cement grade will allow you to obtain a building material with the specified characteristics. The combination of mixture components, according to which the product is produced, will make it possible to produce concrete of the required strength class and hardening speed. Additional parameters provide the properties of the composition for its use in special conditions - high and low temperatures, high humidity, vibration, and other negative influences. The markings and other properties of the binder are reflected in its packaging.

How to find out how much a standard size bag of cement weighs

The question of how much a bag of cement weighs is relevant in many situations in the process of calculations, procurement of materials, and implementation of repair and construction work.
Specific gravity is an important indicator that demonstrates the ratio of mass to occupied volume. We can say that this is an indicator of the density of bulk material. And this parameter is important when choosing cement and drawing up the proportion of the solution mixed on the base of the material. Each brand of cement has its own specific gravity and therefore it is important to know the ratio of volume to mass in order to be able to mix the solution in the correct proportion with the desired characteristics.

Composition and fractions

In addition to the additives used, the quality and characteristics of cements are directly influenced by such factors as the fineness of their grinding, the granulometric composition of the product, as well as the shape of the particles included in the powder mixture.

The bulk of cement compositions, as a rule, consists of grains having sizes from 5-10 to 30-40 microns. The quality of the grinding material is determined by the presence of residues on sieves with mesh sizes of 0.2, 0.08 or 0.06 mm, as well as by testing on specialized devices that determine the specific surface area of ​​the powder.

These devices also serve to determine the air permeability of the material.

Modern industry produces cements that are as finely ground as possible, with increased strength and a high hardening rate. For example, ordinary Portland cements are crushed to 5-8% particle residue on a 0.08 sieve. Grinding of fast-hardening cements occurs to a residue of 2-4% or less.

The specific surface area is 2500-3000 cm2/g of product in the first case and 3500-4500 cm2/g of material in the second.

After reaching a specific surface area of ​​7000-8000 cm2/g, the strength characteristics of cement begin to decrease. For this reason, excessive grinding of cement into dust is considered unsustainable.

According to studies and practical experiences in the field of testing various grades of cement, it has been proven that the main influence on the activity of the material in the short term is exerted by fractions whose size is up to 20 microns. Larger grains (within 30-50 microns) affect the activity of cements at later stages of their hardening.

Thus, by grinding the starting material to a finer state, it is possible to obtain cements of varying degrees of strength and grades. For example, materials marked M600, M700 and M800 are obtained from clinker crushed to contain 45, 50, 65 and 80% of fractions with sizes from 0 to 20 mm in the total powder composition.

The video talks about the marking of cement according to the old and new GOST and their differences:

Specifications

The M500 cement grade demonstrates high performance characteristics. The mixture is especially popular due to its strength, reliability and durability, as well as versatility.

Main properties of Portland cement M500:

• Start of setting – 45 minutes after mixing
• Complete hardening and strength gain - within 28 days
• Frost resistance – about 70 freeze/thaw cycles
• Bending load – up to 6.3 MPa (63 atmospheres)
• Grinding fineness – 92%
• Hygroscopic expansion – maximum 10 millimeters
• Compressive strength – 59.9 MPa (591 atmospheres)
• The shelf life of the dry mixture is about 1 year in original, undamaged packaging (despite the fact that the packages usually indicate M500 for 12 months, after 3-6 months it gradually loses its properties)
• Radioactivity – up to 370 BC/kg (class 1)
• Density – up to 3200 kg/m3

Density

Density is an informative indicator that is responsible for the quality of the binder. It is the density that affects the reliability and strength of the hardened stone. The higher the bulk density indicator of Portland cement (PC) 500, the lower the porosity of the monolith will be and the worse it will absorb water and collapse under frost and various loads.

M500 can vary between 1100-1600 kg/m3. In calculations, an indicator of 1300 kg/m3 is usually used. The true density of the material is 3200 kg/m3.

Supplements

Various additives are introduced into Portland 500 cement, designed to improve certain of its properties and perform other tasks.

Main types of cement additives:

• To regulate properties - affect strength, setting time, plasticity, water absorption.
• Material – influence the processes of hydration and hardening. These can be active mineral additives or fillers.
• Technological - influence the grinding process, which can in a certain way affect the characteristics of the material, but is not at all necessary.

The volume of additives may vary, as indicated by the labeling. D0 is cement without additives, D5 or D20, for example, is cement that contains 5% and 20% of different substances, respectively. All additives are designed to improve the characteristics of the binder, to one degree or another.

Consumption rates

Portland cement M500 is supplied in bags of 25 kg, 50 kg (more in demand). And the question of how much binder is needed to prepare the solution is relevant for all craftsmen. Consumption rates depend on what kind of concrete needs to be prepared and why. Masonry and plaster mixtures are made from cement and sand in a ratio of 1:3, 1:2.

As a rule, the following components are used to fill and create durable structures: clean sand (without clay, silt, debris, small crushed stone), crushed stone with frost resistance F-65 and strength minimum M1000, Portland cement M500.

M500 for different solutions:

• Concrete M200 – 250 kilograms
• M250 – 300 kilograms
• M300 – 350 kilograms
• M350 – 400 kilograms
• M400 – 450 kilograms

It is almost impossible to prepare concrete with a strength of M300 or higher at home, since it requires thorough mixing, which is extremely difficult to achieve without the use of technological equipment.

Packing and packing

Cement is produced and supplied in any volume. Standard packaging of M500 is in bags of 25, 50 kg (you can find M500 40 kg, but less often). After production, the cement is distributed into sealed towers, where a powerful ventilation system with a low level of air humidity is installed. Here the binder can be stored for up to 14 days.

Then the Portland cement is packaged in paper bags. The gross weight of the bag is no more than 51 kilograms. The bags must be made of several layers of polyethylene to prevent moisture from penetrating the powder. The packaging indicates the packaging date and markings with basic symbols that provide information about the material.

Under production conditions, the M500 should only be stored in its original container and for no more than a few months. If you plan to store it for a long time, the bags are placed on special pallets and turned over every 2 months.

Storage conditions: normal humidity level, air temperature up to +50 degrees. When in contact with air, cement absorbs moisture from it, which reduces its properties. Also, the binder loses parameters every few months, so the highest quality mortar can be obtained from fresh cement.

How much concrete will be produced from a bag of cement?

Often proportions are indicated in volume fractions and therefore, when making calculations, it is useful to know how much concrete can be made from one bag of cement. But we need to talk about a specific brand and a specific concrete solution. The proportions are different and you need to decide on this first. The difference is significant - this can be seen from the following table.

How much concrete will be produced from 10 liters of cement?

For each binder and each brand, you will again have to count separately. For each concrete, the approximate consumption of cement for the production of one cube of mortar is known. Based on these data, you can calculate how much solution can be obtained from a kilogram of cement. Next, it is easy to find out the amount of concrete that can be obtained from a bag of cement.

Binder consumption by concrete grade

For example, a cube of M300 concrete requires 350 kilograms of M400 cement. That is, from one kilogram we get 1 m³ / 350 kg = 0.0028 m³. To find out how much M400 concrete you can get from a 50 kg bag, multiply by 50. We get 0.14 m³. As you can see, the calculations are simple.

To consolidate the information, let’s calculate for M200 mortar and the same M400 Portland cement. This type of concrete requires 250 kg. Then from a kilogram we get 1 cubic meter / 250 kg = 0.004 cubic meters. Then from 50 kg it will be: 0.004 * 50 = 0.2 cubic meters, from 40 kg - 0.004 * 40 = 0.16 cubic meters.

Source

Principles of calculation

In laboratory conditions, the bulk density of cement is calculated according to GOST 9758-2012 “Porous inorganic aggregates for construction work. Test methods". To perform measurements, use an oven (according to the current standard, the sample must be dried), a cylindrical measuring vessel, a scoop, a funnel, a metal ruler and a scale.

To independently determine the bulk density of the cement to be used for preparing mortar or concrete, a drying oven is not required. It is most convenient to use a cylindrical measuring vessel with a volume of 1 liter - at the first stage of work it needs to be weighed.

The vessel is filled with cement using a funnel and a scoop; the material is poured into a small mound, which is removed flush with the edges of the container using a steel ruler or slat. Then weighing is carried out. You cannot shake the vessel or compact the material - this will affect the reliability of the calculations.

To find out the bulk density of cement, you need to subtract the mass of the measuring vessel from the obtained mass value and divide the result by the volume of this vessel.

The choice is yours!

If you think that cement in factory packaging is expensive, then it is not so. There are certain quality standards and factories comply with them. These are not inflated prices, but real prices for real quality products. In fact, by buying high-quality materials you always save. If you are offered M500 cement with delivery to Moscow at the price of pick-up from the factory, you are being deceived!

In our company you can buy M500 D0 cement with delivery directly from the manufacturer . Cement delivery is carried out by Euro trucks of 20 tons. It is also possible to order from 10 tons. At your request, cement can be supplied or without stretch film

If you are satisfied with the M500 cement that you purchase from transshipments, then you are satisfied with the cement with the actual M400 grade. In our company you can buy M400 cement with delivery from the manufacturing plant and it will cost you less.

Why are supplements needed?

It would seem that if all these “additives” so degrade the performance of finished concrete structures, why introduce them at all? However, they are not included in the mix to reduce the cost.

“Pure” cement mixtures are characterized by fairly average resistance to aggressive factors from the external environment. They do not tolerate sudden temperature changes, especially in conditions with cold winters or even permafrost. They don't cope well with constant exposure to moisture.

And additions to the composition of the mixture help the material become more practical. The positive effects of “additives” are as follows: Increased resistance to constant or short-term exposure to moisture, including soil moisture or that naturally formed in basements and similar recesses; The ability to resist the appearance and effect of corrosion, which is especially important for reinforced concrete structures and various utilities laid through floor slabs; Internal strength, which manifests itself during prolonged exposure to low temperatures and sudden changes in climatic conditions. Of course, the hardening speed and mechanical strength of such materials will be lower than that of pure clinker, but in some operating conditions they will prove to be more reliable and durable.

Proportions of cement solutions

The weight of the bag is always indicated on the bag itself, but the density of cement can change even within the same substance stored for different times. Therefore, you need to be able to convert some quantities into others and vice versa.

So, to mix a mortar from M500 cement, you need to take the following proportion: 1 part cement, 2 parts sand, 4 parts crushed stone. From the ratio you can determine the volumes of each of the components: to do this, take the total volume of the solution that needs to be obtained and divide it by the number of parts. So, if you need to get 1 cubic meter of solution, then per part there will be 1:7 = 0.142 m3. One part of any of the components is equal to this indicator.

• 1 part of cement – ​​0.142 m3.
• 2 parts sand – 0.284 m3.
• 4 parts of crushed stone – 0.568 m3.

To obtain values ​​in kilograms, you simply need to use the bulk density of each material, multiplying by the desired volume. So, if 1m3 of M500 cement contains 1500 kilograms of material, then in this case you need 1500x0.142=213 kilograms of cement, 1800x0.284=511 kilograms of sand, 1400x0.568=795 kilograms of crushed stone. Water takes up half the volume of cement.

Mixture recipes can be different; when choosing, two main factors are taken into account: the brand of binder used (should not be much lower or higher than the desired brand of concrete), the purpose of the solution (for pouring a foundation or floor, laying bricks, plastering, creating products, etc. ).

• To prepare M100 grade concrete, use: 1:4.5:7 (M400 grade cement, sand and crushed stone) or 1:5.8:8 (with M500 grade cement).
• Concrete M250: 1:2:4 (cement M400) and 1:2.5:4.5 (cement M500).
• Concrete M400: 1:2:3.7 (from M400 cement) and 1:1.5:3.2 (from M500 cement).

The following rule works here: the higher the grade of cement, the less fillers are added and the lower the specific gravity of a cubic meter of finished concrete.

How many buckets are in a 50 kg bag of cement - how to calculate

The question of how much a bag of cement weighs is relevant in many situations in the process of calculations, procurement of materials, and implementation of repair and construction work. Specific gravity is an important indicator that demonstrates the ratio of mass to occupied volume.

We can say that this is an indicator of the density of bulk material. And this parameter is important when choosing cement and drawing up the proportion of the solution mixed on the base of the material. Each brand of cement has its own specific gravity and therefore it is important to know the ratio of volume to mass in order to be able to mix the solution in the correct proportion with the desired characteristics.