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What is Autoclaved Aerated Concrete?

Autoclaved Aerated Concrete (AAC) is a lightweight and porous concrete building made from cement, lime, fly ash, and other raw materials, adding appropriate water and admixtures after mixing, pouring, static stopping, cutting, and autoclaving.

Autoclaved Aerated Concrete is characterized by lightweight, good heat preservation and insulation, and good sound insulation and fireproof performance. The weight per unit volume of autoclaved aerated concrete is about one-third of that of clay bricks, the thermal insulation performance is 3-4 times that of clay bricks, the sound insulation performance is two times that of clay bricks, the seepage resistance is more than double of that of clay bricks, and the fire resistance performance is 6-8 times of that of reinforced concrete. It is widely used in various buildings, such as exterior walls, interior walls, floor slabs, etc. It is an excellent environmentally friendly building material.

The process of making autoclaved aerated concrete is as follows:

1.Preparation of materials

Firstly, raw materials are transported into the factory by various vehicles and stored in the warehouse or yard. Then, the siliceous materials, such as sand, fly ash, etc., are ground fine, which, according to the requirements of raw materials and process characteristics, can either be dry ground into powder and then made into slurry by adding water and mixing, or can be directly input into the ball mill with water and wet grinding slurry, but also with a portion of lime, phosphorus gypsum and other mixing and so on. At the same time, the lime is crushed and stored in the powdered lime silo after being finely ground by the ball mill. Cement is directly hauled by cement tankers and pumped into the cement silo. Aluminum powder is regularly purchased in the right quantity and stored in a cool and dry warehouse according to the monthly plan. The reserve of raw materials is mainly to ensure the continuity of production and the stability of raw materials and to realize a reasonable proportion of raw materials of different sources and qualities to meet the process requirements and produce qualified products.

2. Batching

Batching is preparing and storing all kinds of raw materials to be used, measuring them according to certain requirements, storing them temporarily in the matching containers, and then adding them to the mixing equipment according to the order of the requirements of the production process to carry out the pouring operation. The batching process is a critical link in the production process of aerated concrete, which is related to whether the batching is reasonable and has a direct and important influence on the aerating process, hardening process, and the final performance of the products.

3.Pouring

The pouring process is to put the materials temporarily stored in the former batching process after measurement into the pouring car according to the order of the process, and after mixing by the pouring machine, make the mixed slurry to meet the time, temperature and consistency requirements stipulated in the production process, and then pour it into the molds, and then form the billet through the static stop maintenance process. All kinds of materials are put into the casting car through the casting mixer, constantly stirring so that the materials are fully mixed, and a series of preliminary chemical reactions will occur. The casting process is an important process of whether aerated concrete can form a good pore structure, constituting the core link between the production process of aerated concrete and the batching process.

4. Static curing

 The static curing process is mainly to promote the completion of the casting of the mixed slurry to continue to complete the gas expansion and thickening, and ultimately complete the hardening of the billet in the mold long and high so that the aerated concrete billet to achieve a certain cutting strength, easy to cut and process. Hardening of aerated concrete billet mainly relies on the internal hydration capacity of aerated concrete billet materials, the chemical reaction that occurs, and the heat released to promote, but the external environmental temperature should not be ignored. The static stop conservation process is generally not much operation. Most manufacturers attach great importance to the impact of ambient temperature with ambient temperature regulation facilities.

5. Cutting

The cutting process divides the aerated concrete embryo body and appearance processing to reach the requirements of the appearance of aerated concrete products. The cutting process reflects the characteristics of large-scale mechanized production of aerated concrete; through a special cutting machine cutting, the appearance of aerated concrete products can be flexible and have diverse dimensions to meet the various needs of users. The working condition of the cutting machine not only directly determines the appearance quality and some internal quality of aerated concrete products but also directly affects the production efficiency of the whole aerated block production line. Therefore, in the production process of aerated products must pay great attention to the cutting process.

6. Autoclaved maintenance

Autoclaved maintenance is a high-pressure steam maintenance of aerated concrete billet. Autoclaved aerated concrete production is necessary at the appropriate temperature and pressure of saturated steam curing, experiencing enough time for the body to complete a series of physicochemical changes, thus producing due strength into the qualified products we need. In this high temperature, high humidity, and closed environmental conditions, the aerated concrete body will be fully hydrated inside the body, generating the required Tobol mullite and other hydrates and forming the required compressive strength. Steam curing operation should be standardized and appropriate. Otherwise, some problems will occur, and when serious, there will be more waste products, affecting the yield of the product.

Out of kettle process is the last process of aerated concrete production, including aerated concrete products out of the kettle, lifting, breaking, inspection, packaging, and so on. The out-of-kettle process provides qualified products to the market and the next production cycle to ensure normal progress.

Concrete additives Supplier

TRUNNANO is a reliable concrete additives supplier with over 12-year experience in nano-building energy conservation and nanotechnology development.

If you are looking for high-quality concrete additives, please feel free to contact us and send an inquiry. (sales@cabr-concrete.com)

We accept payment via Credit Card, T/T, West Union, and Paypal. TRUNNANO will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.

What is CLC blocks? 

CLC blocks is a new type of wall material for energy saving and environmental protection, which has a wide range of materials, including cement, slag, river sand, fly ash, slag, etc. 

These raw materials are stirred and foamed to form concrete materials with microporous bubble structures and then made by cutting, maintenance, and other processes. 

CLC blocks have the advantages of environmental protection, energy saving, stable performance, etc. 

Advantages of CLC blocks. 

CLC blocks have the following advantages: 

High strength: CLC block has high compressive, flexural, and tensile strength, which can meet the load-bearing needs of buildings. 

Lightweight: The density of CLC blocks is small, which can reduce buildings' weight and energy consumption. 

Thermal insulation: CLC block has good thermal insulation performance, which can effectively reduce the energy consumption of buildings. 

Sound insulation: CLC block has a good sound insulation effect, which can effectively reduce the impact of noise on the interior of the building. 

Thermal insulation: CLC block has good thermal insulation performance, which can effectively improve the thermal performance of buildings. 

Convenient construction: A CLC block is convenient and fast, which can greatly shorten the construction period and improve the construction efficiency. 

Environmental protection: CLC block is a kind of green building material that can effectively reduce the pollution of the environment. 

Economy: Although the price of CLC block is higher than that of traditional clay brick, it has a long service life and can effectively reduce the maintenance cost of the building. 

How to produce CLC blocks?

The production steps of CLC blocks mainly include: 

Mix various raw materials (such as cement, slag, river sand, fly ash, etc.) according to a certain proportion. 

Add enough water to stir to make the raw materials form uniform concrete. 

Pour the concrete into the block mold and let the concrete fully solidify for some time. 

The solidified blocks are molded and maintained. 

Carry on the quality inspection to the finished block; after qualification, it can be used in the factory. 

The following points should be paid attention to in the production process: 

The proportion of raw materials should be reasonable to ensure the strength of concrete. 

Mixing should be fully uniform to ensure the quality of concrete. 

Application Prospect of CLC Blocks 

After demoulding, the block should be maintained in time to ensure the strength and stability of the block. 

Quality inspection should be strict to ensure that the blocks shipped from the factory meet the requirements of relevant standards. 

As a new type of energy-saving and environmental protection wall material, CLC block has a wide application prospect. 

At present, CLC blocks are mainly used in the following aspects: 

Building exterior wall: CLC block can be used as the thermal insulation material of building exterior wall, which has good heat insulation, sound insulation, and thermal insulation performance. 

At the same time, it is also a green building material, in line with the current concept of building energy saving and environmental protection. 

Building interior wall: CLC block can be used as the partition material of the interior wall, which has good sound and thermal insulation performance. 

At the same time, it is also a kind of green building material that can effectively improve indoor air quality. 

Industrial buildings: CLC blocks can be used in the outer and inner walls of industrial factory buildings, with the advantages of fire prevention, durability, environmental protection, etc. 

At the same time, it is also a green building material, which can effectively reduce environmental pollution. 

Civil buildings: CLC blocks can be used for civil residential external wall maintenance, internal wall partition, flat roofs, etc., with thermal insulation, sound insulation, fire prevention, and other advantages. 

At the same time, it is also a kind of green building material that can effectively improve the living environment. 

In a word, CLC block is a kind of energy saving and environmental protection wall material with a wide application prospect, and its application prospect is very broad in the future.

CLC block additives Supplier

TRUNNANO is a reliable CLC additives supplier with over 12-year experience in nano-building energy conservation and nanotechnology development.

If you are looking for high-quality concrete additives, please feel free to contact us and send an inquiry. (sales@cabr-concrete.com)

We accept payment via Credit Card, T/T, West Union, and Paypal. TRUNNANO will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.

Temperature crack
During the construction of mass concrete structures, the change in air temperature greatly influences the prevention of cracks in mass concrete. 
The internal temperature of concrete comprises the superposition of pouring temperature, adiabatic temperature rise of cement hydration heat, and heat dissipation temperature of the structure. 
The pouring temperature is directly related to the air temperature. The higher the temperature, the higher the pouring temperature of concrete; if the temperature decreases, it will increase the internal and external temperature gradient of mass concrete. 
If the temperature drops too fast, it will cause great thermal stress, easily leading to concrete cracking. 
In addition, humidity also greatly influences the cracks of concrete; when the humidity decreases, it will accelerate the dry shrinkage of concrete. It will also lead to cracks in concrete. 
Temperature cracks often occur on the surface of mass concrete or concrete structures with large temperature differences. 
After concrete pouring, in the hardening process, cement hydration produces a large amount of hydration heat (when the amount of cement is 350 to 550 kg/, per cubic meter of concrete, the heat of 17500~27500kJ will be released, the internal temperature of concrete will rise to about 70 ℃ or even higher). 
Due to the large volume of concrete, a large amount of hydration heat accumulates inside the concrete. It is not easy to distribute, which leads to a sharp rise in internal temperature and rapid heat dissipation on the surface of concrete, thus forming a larger temperature difference between inside and outside. The larger temperature difference causes different degrees of internal and external thermal expansion and cold shrinkage, resulting in a certain tensile stress on the surface of concrete (practice shows that when the temperature difference of concrete itself reaches 25 ℃ ~ 26 ℃. 
The tensile stress in the concrete is about 10MPa). 
When the tensile stress exceeds the tensile strength limit of concrete, cracks will occur on the surface of concrete, often occurring in the middle and later stages of concrete construction. 
In the construction of concrete, when the temperature difference changes greatly or when a cold wave attacks the concrete, it will lead to a sharp decrease in the surface temperature of the concrete and produce shrinkage. The internal concrete restricts the concrete with surface shrinkage. 
The crack width varies and is affected by the change in temperature, which is wider in winter and narrower in summer. 
The temperature crack of concrete caused by high-temperature expansion is usually thick in the middle and thin at both ends, while the thickness of the cold shrinkage crack is not obvious. 
The appearance of this kind of crack will cause the corrosion of steel bars and the carbonization of concrete and reduce the freeze-thaw resistance, fatigue resistance, and impermeability of concrete. 

Main preventive measures: 
(1) Try to choose low-heat or medium-heat cement, such as slag cement, fly ash cement, and so on. 
(2) Reduce the amount of cement. Keep the amount of cement below 450kg/m3 as far as possible. 
(3) When the water-cement ratio is reduced, the water-cement ratio of general concrete is controlled below 0.6. 
(4) improving aggregate gradation and adding fly ash or superplasticizer to reduce the amount of cement and hydration heat. 
(5) improve the mixing technology of concrete, adopt the new technology of secondary air cooling based on the traditional three-cooling technology, and reduce the pouring temperature of concrete. 
(6) Adding a certain amount of admixture with the functions of reducing water, plasticizing, and retarding in concrete to improve the fluidity and water retention of concrete mixture, reduce the heat of hydration and postpone the appearance of heat peak. 
(7) When pouring in a high-temperature season, auxiliary measures such as setting up sunshade boards can be adopted to control the temperature rise of concrete and reduce the temperature of pouring concrete. 
(8) The thermal stress of mass concrete is related to the structure size, and the larger the concrete structure size is. The greater the temperature stress is, so it is necessary to arrange the construction procedure reasonably, layer by layer and block pouring, to facilitate heat dissipation and reduce constraints. 
(9) Set up a cooling pipe inside the mass concrete. Cool through cold water or air to reduce the concrete's internal and external temperature difference. 
(10) Strengthen the monitoring of concrete temperature and take cooling and protection measures in time. 
(11) Reserve temperature shrinkage seam. 
(12) To reduce the constraint, it is advisable to lay a sand cushion of around 5mm on bedrock and old concrete or use materials such as asphalt before pouring concrete. 
(13) Strengthen concrete maintenance, cover it with wet straw curtains and flax sheets after concrete pouring, pay attention to sprinkling maintenance, and appropriately prolong the curing time to ensure the concrete surface cools slowly. 
Heat preservation measures should be installed on the concrete surface in the cold season to prevent the cold wave from attacking. 
(14) A small amount of steel bar or fiber material is installed in the concrete to control the temperature crack of the concrete within a certain range.

Concrete additives Supplier

TRUNNANO is a reliable concrete additives supplier with over 12-year experience in nano-building energy conservation and nanotechnology development.

If you are looking for high-quality concrete additives, please feel free to contact us and send an inquiry. (sales@cabr-concrete.com)

We accept payment via Credit Card, T/T, West Union, and Paypal. TRUNNANO will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.

Aerogel felt is a flexible insulation made of nano silica or metal aerogel as the main material, carbon fibre or ceramic glass fibre cotton, or pre-oxidized fibre felt through a special process, whose characteristics are low thermal conductivity, certain tensile and compressive strength. It belongs to a new type of pipeline insulation material.

Features of Aerogel Felt 

1. Arogel felt is currently the solid thermal insulation material with the lowest thermal conductivity at about 400°C. In contrast, its thermal conductivity exexceeds the micro-nano thermal insulation series in the high-temperature range of 400-1000°C.

2. Aerogel felt has various features, such as softness, easy cutting, low density, inorganic fire prevention, overall hydrophobicity, green environmental protection, etc. It is capable of replacing traditional flexible insulation materials like glass fibre products, asbestos insulation felt, silicate fibre products, etc. 

3. Density of aerogel felt is 180～220kg/m³, applicable temperature -200℃—+400℃, thermal conductivity: 0.018w/m·k (at 25℃).

4. Aerogel felt has absolute hydrophobicity (below 350°C).

5. Aerogel felt has an excellent heat insulation effect. Aerogel felt provides 2-5 times more insulation than conventional insulation. Its theoretical service life, determined by the Arrhenius experiment, is almost 20 years as long as the building.

2. Aerogel felt can reduce the thickness of the insulation layer. Aerogel felt achieves the same thermal insulation consequence, while the thickness is only a fraction of other traditional materials. In addition, the heat loss is small, and the space utilization rate is high after heat preservation and at high temperatures; the above performance advantages are more obvious.

3. Aerogel is hydrophobic and fireproof. The aerogel felt is hydrophobic, effectively preventing moisture from entering the interior of the pipeline and the equipment. Simultaneously, with the building A1 fireproof performance, aerogel's unique three-dimensional network structure avoids the obvious decline in the insulation effect, such as sintering deformation and settlement during long-term high-temperature use that other insulation materials have.

4. Aerogel felt is lightweight, easy to cut and sew to meet various shapes of pipes and equipment for heat preservation requirements and requires less time and human resources for installation.

What is aerogel felt used for?

1. Aerogel felt can be used for thermal insulation of industrial storage tanks, kiln LNG and cold chain equipment.

2. Construction: Aerogel felt can be used for thermal insulation of exterior walls, interior walls, roofs of industrial buildings, fire protection and thermal insulation of steel frame structures, and paint-coated fabric thermal insulation products.

3. Military use: Aerogel felt can be used for thermal insulation of large ships and submarines, heat insulation of engines, chimneys, LNG carriers and pipelines, and fire protection.

4. Transportation: Aerogel felts can be used for new energy vehicles and rail transit; fire and heat insulation for power batteries, engines, and automobiles; high-speed railways, subways, and trains for overall heat preservation and fire protection; and high and low-temperature transportation pipelines for cold and heat insulation.

5. Aviation: Aerogels have been applied to next-generation aero-engine heat shields, aero-engine combustion chamber heat shields, missile head heat shields, and can also be used as efficient heat insulation and noise reduction materials for nuclear submarines, nuclear reactors, and evaporators, and It is widely used in military equipment integrating stealth, noise isolation, and explosion protection.

Can aerogel be used in clothing?

Aerogels can be incorporated into textiles without necessarily reducing breathability. In another study, the silica aerogel phase change material applied to fabrics as a coating was also found to reduce air permeability.

Aerogel Felt Supplier

TRUNNANO is a reliable aerogel felt supplier with over 12-year experience in nano-building energy conservation and nanotechnology development.

If you are looking for high-quality aerogel felt, please feel free to contact us and send an inquiry. (sales@cabr-concrete.com)

We accept payment via Credit Card, T/T, West Union, and Paypal. TRUNNANO will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.