Product Description
Foam concrete
Foam concrete by mechanical means by foaming the foaming agent to the foaming system fully foam, and the foam and cement slurry uniformly mixed Situ construction or die molding machine pumping system and then through the foam by natural conservation form a new lightweight insulation material containing a large number of closed pores.
Foam concrete (lightweight concrete, foam cement)A benefits of waste, environmental protection, energy saving, low incombustibility new building energy-saving materials. Lightweight concrete (foam concrete) by chemical or physical means, depending on the application need a gas such as air or nitrogen gas, carbon dioxide gas, oxygen gas introduced into the concrete slurry, after a reasonable conservation molding containing a large number of fine closed pores formed, and a considerable strength of concrete products. The production of lightweight concrete (foam concrete) is usually mechanically prepared in the aqueous solution of a foaming agent into a foam, and then the foam was added to a slurry consisting of siliceous material, calcareous material, water and various additives, etc., mixing, casting, conservation is made of a porous material.
It belongs to the bubble-like insulation material, outstanding feature is to form a closed foam hole inside the concrete, the concrete, lightweight insulation; but also add a special breed of aerated concrete, its pore structure and material properties are close in aerated concrete, and they and the difference, but the difference in the between pore shape processing gas means. aerated concrete pores is generally oval-shaped, foam concrete by the effect of the pores, deformed, forming polyhedra. aerated concrete is to use chemical hair gas generated by internal gas to form pores by chemical reaction, the foam concrete is by mechanical braking bubble methods, the first foaming agent made of foam, and then the foam added to the cement, magnesite gypsum slurry to form a foam slurry, the Conservation of Nature Conservation vapors made.
Foam concrete is a new type of energy saving and environment-friendly building materials, domestic and foreign scholars have done a lot of research and development, it is widely used in wall materials, but there are still some drawbacks, such as low strength, cracking, absorbent, thus further expanding the application areas of need in the foaming agent, mixing ratio, process, equipment, etc., to do further research.
Foam concrete is a concrete family, in recent years, at home and abroad are attaches great importance to the foam concrete research and development, its more widely applied in the field of architecture, and now the situation is described as follows:
First, the characteristics of the foam concrete:
Foam concrete is usually mechanically prepared by the aqueous solution of the foaming agent into a foam, and then the foam was added to a slurry containing a siliceous material, calcareous material, water and various additives and other components, by mixing, casting molding, curing made of a porous material. Contains a large number of closed pores in the foam concrete, it has the following good physical and mechanical properties.
1, light
Smaller the density of the foam concrete density levels generally 300-1800kg/m3, commonly used foam concrete density rating of 300-1200 kg/m3, in recent years, the density of 160 kg/m3 lightweight foam concrete is also building project application. Due to the density of the foam concrete used in the inside and outside of the building wall, level floor, columns and other architectural structure of the material, and generally allows the weight of buildings around a 25% reduction in the structure of some of up to a total weight of 30 % -40%. Moreover, structural members, such as the use of foam concrete instead of ordinary concrete, can increase member commitment cut capacity. Therefore, foam concrete has significant economic benefits in construction engineering.
2, good thermal insulation properties
Foam concrete containing a large number of small pores closed, it has good thermal performance, good thermal insulation properties, the ordinary concrete do not have. Usually foam concrete density levels in the range of 300-1200 kg/m3, thermal conductivity 0.08-0.3w / (m • K), the thermal resistance of about 10 to 20 times that of ordinary concrete. Foam concrete as a building wall and roofing materials, has a good energy saving effect.
3, good sound insulation fire resistance
Foam concrete is a porous material, so it is a good soundproofing material in the floors of the building and highway noise barriers, the top level of the underground buildings of the material can be used as an insulation layer. Foam concrete is an inorganic material that does not burn, and which has good fire resistance, for use in the building, can improve the fire performance of the building
4, the overall performance is good
Field-cast construction, closely combined with the main project.
5, low elastic damping
The porous foam concrete so that it has a low modulus of elasticity, so that it have good absorption and dispersion of the impact load.
6, waterproof
Cast-in-place foam concrete low water absorption, relatively independent closed bubbles and good integrity, it has a waterproof performance.
7 durability
Same main project life.
8, easy production and processing
Foam concrete, not only in the factory production into a variety of products, but also on-site construction situ directly into the roof, floor and wall.
9, environmental performance
The foam concrete raw materials required for the cement and foaming agent, foaming agent mostly close to neutral, benzene, formaldehyde and other harmful substances, to avoid environmental pollution and fire hazards.
10, convenient construction
Just use the cement foam machine to automate job pumping to achieve the long-range transport of the vertical height of 200 meters, the workload of 150-300 cubic / working days.
11, other properties
Foam concrete construction process pump is good (0.5-22.2Mpa), high compressive strength, impact energy absorption performance, can be a lot of use of industrial waste, low prices, etc..
Edit this paragraph foam concrete application range:
Foam concrete for its good characteristics, widely used in energy-saving wall materials application in other areas. Currently, foam concrete application in China is mainly the roofing foam concrete cast-in-place insulation layer, foam concrete surface blocks, foam concrete the light wallboard and of foam concrete Compensation Foundation. However, take full advantage of the good characteristics of foam concrete in construction engineering applications continues to expand and speed up the progress of the project to improve the quality of the project, as follows:
(1) used as a retaining wall. Port is mainly used for the dyke. The foam concrete shore wall as lightweight backfill material can reduce the vertical load, and also reduce the other side of the wall of the lateral load. This is because foam concrete is a good bonding properties of a rigid body, it is not applied to the other side of the wall along the perimeter lateral pressure, settlement reduces maintenance costs be reduced, thus saving a lot of expenses. Foam concrete can be used to enhance the stability of the embankment slope, use it instead of the slope of the part of the soil, reduce the quality, and thus reduce the force of the impact slope stability.
(2) the construction of the stadium and athletics track. Use drainage ability permeability of lightweight foam concrete as the basis of above covered with gravel or artificial turf used as a playground. The density of the foam concrete for 800-900kg / m³ such playground hockey, football and tennis activities. Or covered with a layer of foam concrete 0.05m thick porous asphalt layer and the plastic layer, you can make the athletics track.
(3) for sandwich member. Foam concrete prefabricated reinforced concrete components can be used as the inner core, and it has a lightweight, high strength and good insulation properties. Usually using a density of 400 - 600kg / m³ foam concrete.
(4) pipeline backfill. Underground waste oil tank, pipeline (built crude oil, chemicals), sewage pipes and other holes easily result in a fire or landslides, foam concrete backfill resolve these troubles, costs less. The density of the foam concrete depends on the diameter of the pipe and the groundwater level, 600-1100kg / m³.
(5) lean concrete fill layer. Using bendable hose, foam concrete has a lot of work and adaptability, so it is often used for lean concrete fill layer. Such as insulation requirements are not very high, with a density of about 1200kg / m³ lean concrete fill layer, the average thickness of 0.05m; such as high insulation requirements, using the density of 500kg / m³ lean concrete fill layer, the average thickness of 0.1-0.2m.
(6) the roof slope. Foam concrete for roof slope, with the advantages of light weight, speed of construction, inexpensive. The slope of 10mm / m. Thickness of 0.03-0.2m, with a density of 800 - 1200kg / m³ foam concrete.
(7) support of the foot of the tank. Foam concrete order in steel tanks (built in crude oil, chemicals) the bottom of the foot, if necessary, can also be the formation of a convex foundation This ensures that the entire bottom of the support in the welding years in the best state of stress, which a continuous support can tank using thin Xiangdi. Convex foundation is also easy to clean. The use of foam concrete density of 800-1000kg \ m³.
(8) for landscaping. Made of foam concrete bulk density of 600-1000kg / m³, can be used garden rockery, trash, Zhuodeng,, etc..
(9) defense (modern warfare, information and advanced rotary instruments as attack tools), the foam cement can be used to implement immediately, such as airports, important traffic highway repair destruction by enemy bombing military engineering, our equipment and the process can enemy sabotage engineering quick fix, the results of experiments to 10 minutes after the repair for aircraft taking off and landing, chariot through.
(10) other. Foam concrete can also be used for firewall insulation padding, sound insulation floor filling, tunnel liner backfill; well as power supply, water pipeline isolation.
Foam concrete construction technology
The foam concrete construction is completed through a package of special equipment on-site. The equipment package with feeding, stirring, host systems, construction materials on the site, stirring, foaming and sent directly to the construction of the base surface high-pressure pipeline pumping system comes。
Fourth, the development status of the foam concrete:
1 foam concrete results achieved
Many types of foam concrete, but the most commonly used cement foam concrete. Cement foam concrete admixtures to different can be divided into cement - fly ash - lime and cement - slag - lime - plaster, cement - fly ash - sand - lime and cement sand lime and cement - slag - fly ash - lime - plant fiber type [4], cement - sand - glass fiber type and other types.
Xie Minghui cement - fly ash - lime foam concrete pilot study to obtain a density of 691kg/m3, the compressive strength of 3.4MPa, thermal conductivity of 0.210W / (m • K anti-15 freeze-thaw cycles qualified carbonation coefficient of 0.89 foam concrete wall materials.
ARMORED FORCE, Guo Yushun on the cement - Slag - lime - gypsum-type foam concrete experimental research, studies have shown that atmospheric conservation slag porous concrete is an ideal insulation material (density of 910 kg/m3, 28d compressive strength of 9.81MPa) have obvious advantages in price, with a certain degree of market competitiveness.
High wave [7] cement - fly ash - sand - lime-foam concrete pilot study to obtain the best fit fly ash 60%, 5% lime foam liquid 3kg, 15% fine sand, cement 20 % corresponding to the performance of the density record 6kglm3, water absorption of 229 islands, 28d compressive strength of 3.4MPa.
Song Xuhui cement - sand - lime foam concrete pilot study had a density of 812kg / m³, compressive strength of 2.8MPa, thermal conductivity of 0.108W / (m • K anti-15 freeze-thaw cycles. qualified, drying shrinkage foam concrete of 0.43mmlm.
Gao Bo, Wang Qun Li, Experimental study on cement - slag - fly ash - lime - plant fiber-foam concrete, dry density 648kg/m3, the compressive strength 3.6MPa, 12.0% water absorption, resistance to 25 freeze-thaw qualified circulation, drying shrinkage 0.72mm / m, the process is simple, inexpensive and excellent products.
ZHAN Bing root [10] of cement - sand - glass fiber-foam concrete test results show that the the fiber glass Rui increase foam concrete compressive and flexural strength, and greatly improve the toughness, and to some extent inhibited Early shrink and crack.
2 foam concrete defects
(1) low intensity: bulk density for the foam concrete compressive strength of 800-859kg / m³ serious low, generally lower than 2.0MPa, some even less than 1.0MPa. However, the rapid development of domestic foam concrete technology, Beijing enterprises (such as the Beijing Branch building Cheng) to 500 kg per cubic meter of foam concrete strength 2.5MPa.
(2) Open High: foamed concrete in the presence of Na, K, and other damaging effects of the bubble, making stomata mostly openings, seriously affect the insulation properties of the foam concrete. Beijing Hong Ruijia 180 kg level foam concrete do 0.4MPa, and the opening rate is controlled below 10%.
(3) cracking, water absorption: the hardening foam concrete surface cracking, leading to absorb large amounts of external moisture. The cracking can add fiber mitigation, water can be added to a water repellent solve.
