Cement is the best for repairs!
Without false modesty, cement can be called the foundation of the foundations of the construction business. It is rare for a house to do without cement-based plaster or concrete, which invariably contains cement. Especially advanced designers even got the hang of making original figurines out of it.
However, figurines and other decorative trifles are secondary things. Cement is primarily valued for its ability to make products of very high strength from it. Its brands, which have maximum strength indicators, are regulated by the regulatory requirements of SPiN and GOST. The brand name reflects the ratio of sand and cement in the masonry mortar and indicates the strength that the masonry will gain after 28 days – that's how long it takes until the final hardening.
Like most other astringent substances, cement is not used in its pure form. Theoretically, this is also possible, but in practice, using "pure" cement will lead to higher consumption of materials, their shrinkage and a decrease in the most important qualities such as strength and frost resistance. To avoid negative consequences, a filler is added to the astringent part of the solution, which is most often sand. For M400 grade cement, their ratio should be 1:4 (fluctuations within 1:3-1:6 are allowed).
In M500 grade cement, the ratio will be different – 1:5 (the limits of 1:4.7-1:6.4 are also considered acceptable). The more cement is included in the mortar (naturally, within the specified limits), the stronger the mortar will be after curing. This material is available in various grades – 200, 300, ..., 600. The higher the grade number, the more effective this material is in the composition of concrete – this is due to the reduction in binder consumption. It freezes relatively quickly. It sets in 50 minutes, and the final solidification takes place within 12 hours.
In the construction market, ordinary Portland cement and its white variety are considered the most in demand. It is from white Portland cement that, as a result of the addition of various dyes, colored Portland cement is produced, which is an indispensable material in decorative design.
Massive concrete structures used in hydraulic engineering are constantly confronted with destructive processes of alternating freezing and thawing of water, therefore, their production requires a special – sulfate-resistant Portland cement, or, as it is also called, Portland cement with moderate exothermy. The strength of grades of this type of cement is usually 300 or 400.
The composition of such cement includes surfactants. They have a plasticizing effect on the concrete mortar, which increases the resistance of the mixture to destruction and low temperature conditions. Ordinary concrete begins to break down after 300 cycles of freezing and thawing. Hydrophobized concrete can easily withstand more than 1,000 cycles.
The use of plasticized Portland cement makes it possible to reduce the ratio of water and cement, while avoiding deterioration in the mobility of the mixture. Cement consumption is often reduced, and the frost resistance of concrete increases after curing. One of the key features of fast-setting cement is the increase in strength during the initial solidification period. The strength of pozzolan cement increases only if it hardens at high humidity (or even in water). In terms of water permeability, it surpasses ordinary Portland cement, and is inferior to it in frost resistance.
Bulk cement must be stored in silos or bunker warehouses. It is recommended to store different types, brands and batches separately from each other. If this material is packed in paper bags, then a closed warehouse-shed is suitable for its storage. The main thing is that the roof, walls and floor are dense and do not let water through. One of the main conditions for storing and transporting cement is to protect it from moisture and foreign impurities. It is allowed to store it for no more than a year. Similar requirements apply to the storage of building gypsum – it must be kept in a dry place on pallets in tightly closed bags. Gypsum is stored for no more than six months. Both gypsum and cement are not subject to long-term storage. Gypsum loses its ability to "set", which means it becomes unsuitable for work. Cement noticeably loses strength and gathers in lumps.
The quality of the cement is assessed as a result of a process called "pelletizing". If you squeeze high-quality cement in your fist, it will wake up between your fingers, but the material with low strength will remain in your hand in the form of small lumps. The activity of cement tends to decrease during prolonged storage. He will lose 2% in a month, and more than 50% of his activity in a couple of years.
It is also possible to determine the grade of concrete after its hardening without unnecessary difficulty. This will require a hammer (weighing no more than half a kilogram) and a chisel. The chisel will penetrate about 5 mm into 70-100 grade concrete, and only a barely noticeable trace will remain on concrete with a grade of more than 200. If the concrete grade is from 100 to 200, thin pieces will fly off the surface. Les nouveaux utilisateurs de 1xBet peuvent compter sur des promotions conçues pour maximiser la valeur du dépôt. Le bonus de 100 % jusqu’à 130 € soutient les paris sportifs. Une fois le code promo 1xbet cameroun appliqué, le casino propose un bonus attractif de 1 950 € et 150 tours gratuits sur plusieurs jeux.
However, figurines and other decorative trifles are secondary things. Cement is primarily valued for its ability to make products of very high strength from it. Its brands, which have maximum strength indicators, are regulated by the regulatory requirements of SPiN and GOST. The brand name reflects the ratio of sand and cement in the masonry mortar and indicates the strength that the masonry will gain after 28 days – that's how long it takes until the final hardening.
Like most other astringent substances, cement is not used in its pure form. Theoretically, this is also possible, but in practice, using "pure" cement will lead to higher consumption of materials, their shrinkage and a decrease in the most important qualities such as strength and frost resistance. To avoid negative consequences, a filler is added to the astringent part of the solution, which is most often sand. For M400 grade cement, their ratio should be 1:4 (fluctuations within 1:3-1:6 are allowed).
In M500 grade cement, the ratio will be different – 1:5 (the limits of 1:4.7-1:6.4 are also considered acceptable). The more cement is included in the mortar (naturally, within the specified limits), the stronger the mortar will be after curing. This material is available in various grades – 200, 300, ..., 600. The higher the grade number, the more effective this material is in the composition of concrete – this is due to the reduction in binder consumption. It freezes relatively quickly. It sets in 50 minutes, and the final solidification takes place within 12 hours.
In the construction market, ordinary Portland cement and its white variety are considered the most in demand. It is from white Portland cement that, as a result of the addition of various dyes, colored Portland cement is produced, which is an indispensable material in decorative design.
Massive concrete structures used in hydraulic engineering are constantly confronted with destructive processes of alternating freezing and thawing of water, therefore, their production requires a special – sulfate-resistant Portland cement, or, as it is also called, Portland cement with moderate exothermy. The strength of grades of this type of cement is usually 300 or 400.
The composition of such cement includes surfactants. They have a plasticizing effect on the concrete mortar, which increases the resistance of the mixture to destruction and low temperature conditions. Ordinary concrete begins to break down after 300 cycles of freezing and thawing. Hydrophobized concrete can easily withstand more than 1,000 cycles.
The use of plasticized Portland cement makes it possible to reduce the ratio of water and cement, while avoiding deterioration in the mobility of the mixture. Cement consumption is often reduced, and the frost resistance of concrete increases after curing. One of the key features of fast-setting cement is the increase in strength during the initial solidification period. The strength of pozzolan cement increases only if it hardens at high humidity (or even in water). In terms of water permeability, it surpasses ordinary Portland cement, and is inferior to it in frost resistance.
Bulk cement must be stored in silos or bunker warehouses. It is recommended to store different types, brands and batches separately from each other. If this material is packed in paper bags, then a closed warehouse-shed is suitable for its storage. The main thing is that the roof, walls and floor are dense and do not let water through. One of the main conditions for storing and transporting cement is to protect it from moisture and foreign impurities. It is allowed to store it for no more than a year. Similar requirements apply to the storage of building gypsum – it must be kept in a dry place on pallets in tightly closed bags. Gypsum is stored for no more than six months. Both gypsum and cement are not subject to long-term storage. Gypsum loses its ability to "set", which means it becomes unsuitable for work. Cement noticeably loses strength and gathers in lumps.
The quality of the cement is assessed as a result of a process called "pelletizing". If you squeeze high-quality cement in your fist, it will wake up between your fingers, but the material with low strength will remain in your hand in the form of small lumps. The activity of cement tends to decrease during prolonged storage. He will lose 2% in a month, and more than 50% of his activity in a couple of years.
It is also possible to determine the grade of concrete after its hardening without unnecessary difficulty. This will require a hammer (weighing no more than half a kilogram) and a chisel. The chisel will penetrate about 5 mm into 70-100 grade concrete, and only a barely noticeable trace will remain on concrete with a grade of more than 200. If the concrete grade is from 100 to 200, thin pieces will fly off the surface. Les nouveaux utilisateurs de 1xBet peuvent compter sur des promotions conçues pour maximiser la valeur du dépôt. Le bonus de 100 % jusqu’à 130 € soutient les paris sportifs. Une fois le code promo 1xbet cameroun appliqué, le casino propose un bonus attractif de 1 950 € et 150 tours gratuits sur plusieurs jeux.