Research on the application of foam concrete

2019-05-15 16:30:58

Foam concrete, also known as cellular concrete, cellular lightweight concrete,aerated concrete, is widely used in energy-saving wall materials due to its good characteristics and has been applied in other aspects.At present, foam concrete appears in different forms in different application fields, mainly used in the roof foam concrete insulation layer, foam concrete surface block, foam concrete lightweight wallboard, foam concrete compensation foundation and so on.However, by making full use of the good characteristics of cellular concrete, the application field of foamed concrete in construction engineering can be continuously expanded, engineering progress can be accelerated, and engineering quality can be improved, as follows:


1.Retaining wall

Mainly used as the rock wall of the port, foam concrete used as light backfill material behind the shore wall can reduce the vertical load, but also reduce the lateral load of the opposite bank wall.This is because foamed concrete is a rigid body with good bonding performance. It does not exert lateral pressure along the surrounding shore wall, so the settlement is reduced and the maintenance cost is reduced accordingly, thus a lot of expenses are saved.Foam concrete can also be used to improve the stability of the embankment slope, replacing part of the soil of the slope with it, because the quality is reduced, thus reducing the force that affects the stability of the slope.


2.Construction of sports fields and running tracks

Use pervious cellular concrete with strong drainage capacity as a light foundation covered with gravel or artificial turf for the playground.The density of foamed concrete is 800-900kg/m3, and this kind of playground can be used for hockey, football and tennis activities.Or covered with a layer of porous asphalt layer and plastic layer of 0.05m thick on the foam concrete, can be used for track and field.


3. Sandwich member

Foam concrete can be used as the inner core of precast reinforced concrete members, so that it has a good performance of light weight, high strength and heat insulation.Foamed concrete with a density of 400-600kg /m3 is usually used.


4.Backfill the pipeline

Waste underground oil tanks, pipelines (containing crude oil and chemicals), sewage pipes and other holes are easy to cause fire or collapse. Foam concrete backfilling can solve these problems with less cost.The density of foamed concrete depends on the diameter of the pipe and the water table, generally 600-1100kg/m3.


5.Lean concrete filling

Due to the use of flexible hoses, foam concrete has great flexibility and adaptability, so it is often used for poor concrete filling.If the requirement for thermal insulation is not very high, the poor concrete filling with a density of about 1200kg/m3 is adopted with an average thickness of 0.05m. If the requirement for thermal insulation is very high, the poor concrete filling with a density of 500kg/m3 is adopted with an average thickness of 0.1-0.2m.


6. Roof slope

Foam concrete used in roof slope, with light weight, construction speed, low price and other advantages.Generally, the slope is 10mm/m and the thickness is 0.03-0.2m. Foamed concrete with a density of 800-1200kg /m3 is adopted.


7 Support of tank bottom

The foam concrete is stepped at the bottom of the bottom foot of the steel tank (containing crude oil and chemicals). If necessary, a convex foundation can be formed to ensure that the support of the whole tank bottom is in the best stress state during welding. This continuous support enables the tank to adopt the thin plate bottom.The convex foundation is also easy to clean.The working density of foamed concrete is 800-1000kg/m3.


8. For landscaping

The bulk density of foamed concrete is 600-1000kg/m3, which can be used for garden rockery, dustbin, table and stool, etc.


9. National defense (modern war USES information and advanced mechanical equipment as attack tools)

The cellular concrete can be used for immediate rush repair of military projects damaged by enemy bombing, such as airports and important traffic highways. The damaged projects can be quickly repaired.


10.Thermal insulation application

Aerated concrete contains a large number of closed pores. The stagnant air in the pores is a good adiabatic medium and can cut off heat exchange.The lower the density, the more pores and the better the adiabatic property.Especially the density is lower than 500 / m3.The thermal conductivity of foam concrete is less than 0.09w/m.k.Generally, the material with thermal conductivity less than 0.23 is called adiabatic material, and the one with thermal conductivity less than 0.14 is called thermal insulation material.Foam concrete is generally less than 0.14 and less than 0.09, so it is a good thermal insulation material.


11. Application of building thermal insulation

Building thermal insulation is the main application field of foam concrete, accounting for 80% of the total production of cellular  concrete for building thermal insulation.Its good thermal insulation performance and the policy of building energy saving pull it in the field of building thermal insulation began to scale application.If all application building insulation foam concrete, including roofing insulation thermal insulation layer, wall insulation, thermal insulation layer of floor heating (or bed), equal with foam concrete to wrap the whole room, and a square meters building area is about 0.2 ~ 0.5 m3 foam concrete (roof, floor, the walls are calculated by 5 cm thermal insulation layer), a building area of 1 square MiJianZhu, foam concrete is needed from 2000 to 5000 m3.


12.Insulation of pipes and thermal equipment

The demand for thermal insulation materials for thermal pipes and thermal equipment in China is 2.5 million m3/ year, and the demand for thermal insulation materials for thermal pipes and thermal pipes in factories in north China is even more amazing.Nowadays, mineral wool inorganic fiber, the leading product, makes people itch, has strong hydroscopicity, high price, and is in urgent need of replacement. Foam concrete will also play a big role in this aspect.The main products of thermal pipe insulation are prefabricated pipe insulation shell and special-shaped material, as well as thermal insulation panel.


13. Cold storage insulation

Cold storage insulation is now using foam plastics.Because foam plastic is easy to age and shrink and flammable, so developed countries are replaced by foam concrete pouring or masonry insulation layer.Its main use of the whole cast-in-place, roof, wall, ground all foam concrete cast-in-place, seamless.


14.Industrial furnace insulation

Its main products are refractory insulation bricks.Large industrial furnaces, such as steel mills, glass factories, ceramics factories, nonferrous metal smelters and cement kilns, are required to lay a layer of thermal insulation refractory brick on the outside of the refractory brick to reduce energy consumption.Original use bleaching bead brick, alumina bubble brick more, the price is extremely high, at present a lot of countries already began to use foamed concrete firebrick to replace high-priced traditional product, the price is less than its half, have competition ability very much.


15.Sound absorption and sound insulation application

Foamed concrete with open holes is an excellent sound absorbing material, while foamed concrete with closed holes is an excellent sound insulating material. Both of them have a great market, especially sound absorbing material, with a better prospect.

Generally, materials with average sound absorption coefficient greater than 0.2 are called sound absorption materials.There are two kinds of traditional products: fiber (rock wool board, etc.) and porous (foam plastic and foam glass, etc.).Foamed concrete is a new type of porous sound absorption material, its average sound absorption coefficient is 0.8~1.4, is a strong sound absorption material, can reach the level 1 or 2 standards.It has great market and competitive advantages in the following applications.

(1) Outdoor sound-absorbing materials (highway and railway sound-absorbing barriers)

Foam concrete outdoor sound-absorbing material market is the main highway and railway on both sides of the sound-absorbing barrier.Roads and railways in public facilities, for example in the United States, require at least 30 million cubic meters of sound barriers.Nowadays, the sound absorption barriers for roads are mainly wood chips, cement boards and foam glass boards.The former has very low sound absorption coefficient, can not meet the needs of high-speed railway, and not beautiful, the latter price is too high.The sound absorption performance of foam concrete is good, can meet any road sound absorption requirements, but the price is very low, is the development opportunity of foam concrete.

(2) Indoor wall absorption

Indoor sound absorption has sound absorption ceiling and sound absorption wall. Cellular concrete has great market advantage in sound absorption on walls.Compared with rock mineral wool and other fiber sound absorption board, it has the disadvantage of no cutting and installation, and good strength and low price.There will be a big market for subway walls, as well as for other building walls such as shopping malls, station waiting rooms, movie theaters and conference halls.

(3) Sound insulation sandwich panel (partition panel)

The existing indoor partition are installed on both sides of wooden keel plasterboard of face of 5 ~ 10 , inside the wall is empty, no sound insulation, also not strong, also can't nail nails.Foam concrete compound 5 thick sound insulation board, of the space is little, two surface for color adornment layer, the intermediate of 4 thick foam concrete, partition combined with sound insulation, twice as fast installation, welcomed by consumers.


16.Fireproof material


(1) Fire rated doors

Fire  rated doors are large lifting doors for middle and high-rise buildings to cut off the spread of fire. They are essential fire structures for building codes. China's existing buildings have a market demand of about 600 million yuan per year.In March 2009, the implementation of the new fire door standards, improve the fire level, the original products do not meet the standards, the manufacturers are developing foam concrete fire door core.This market is now in urgent need of supplies and there is no satisfactory products, development prospects are particularly promising.

(2) Fireproof board

Foam fire prevention board, fireproof sex is stronger, the foam density dropped to 800 after  / m3, lightweight sex is outstanding, has the very big market advantage.Some enterprises in Beijing, shandong and other places all use our foaming technology to produce fireproof board, which is very successful and has promotion significance.


17. Military applications of shooting and explosive energy absorption protection

Cellular lightweight concrete has a good absorbing effect on bullet impact and explosion shock wave, which can greatly reduce the destructive power of shooting and explosion.In terms of anti-explosion, the products with development significance include military and civil products:

(1) Military

Cellular lightweight concrete can be used in various underground or above ground military projects, ammunition depots and so on.Adding dozens of centimeters of foamed concrete (cast-in-place or masonry) to the walls and top of its engineering can reduce the explosion damage.In addition, the assembled foam concrete shockproof command post and field hospital building have great development value.

(2) Civil use

Anti-explosion foam concrete is mainly used in explosive storehouse, explosive chemical raw material storehouse, explosive equipment workshop, when it has an accident, it can reduce explosion damage and reduce loss.


18. Application of anti-electromagnetic radiation

Aerated concrete is an excellent electromagnetic shielding material, which can absorb and eliminate electromagnetic waves.In recent years, it began to be used in military and civil buildings with large electromagnetic radiation. Its products are radiation-proof panels, which are in great demand, especially in military industry.It is estimated that the domestic market demand is about 500,000 m3 per year, which is very high in developed countries.


19. Application of percolation and filtration functions

Aerated concrete with an opening rate of more than 80% has excellent percolation and filtration functions, so it has a broad application prospect.

(1) Permeable floor tile

The permeable brick developed by Beijing renchuang group has been highly praised by the state leaders, but it cannot be popularized due to its high price and is only used in some high-end places.General foam concrete permeable brick, with the same water permeability, but the cost is only 1/5-1/10, can be widely used.

(2) Breathable grass surface

Permeable brick also is permeable brick.Water and air permeability can make plants grow under the foamed concrete ground, and grow to the ground through the pores, forming green vegetation.Taking advantage of this, the United States has developed the cast-in-place cover of foam concrete dump sites, the cast-in-place cover of roads and railways and the slope protection of embankment Banks, and the sand control cover of sandy land.The grass can still grow after the foam concrete is poured, which solves the contradiction between covering concrete and greening grass.

(3) River sand water filtration

There are many bailers in the river, and the sand should be leached out as soon as possible.Using foamed concrete as the filter layer is quick and good.Other such as water quench slag, industrial residue can use this filter board.


20. Industrial machinery filtration layer

The foam concrete is made into the filter element of the filter, which has the advantages of low cost, good filtering effect and high cost but difficult to make.


21.Airport protective energy absorption application




Cellular lightweight concrete has strong impact resistance.Ordinary concrete can be broken with a sledgehammer, but it is difficult to break the foam concrete.Using this kind of energy absorption, foreign countries have developed and applied a number of high value-added products, such as airport safety protection foam block, racing field safety protection foam block, road accident prone area safety protection foam block and so on.When the aircraft or car out of control of the runway or road, into the foam block protection belt, due to the impact absorption of foam block, make it stop and protect the aircraft or vehicle without damage.


22. Application of impermeable and waterproof functions

The closed-cell foamed concrete has hydrophobicity, and the drop water has lotus leaf dewdrop effect, so its impermeability and waterproofing are excellent.There are two main markets for this foam concrete:



(1) Building waterproofing and engineering waterproofing

In all parts of the building that need to be waterproof, such as roof, basement, toilet, pouring or masonry foam concrete, can save waterproof agent, and achieve permanent waterproof, overcome the shortcomings of waterproof coating easy to fall off failure.Replace waterproof material with it, cost low, life is long, have competition more.In water conservancy projects such as canals, pools, towers, swimming pools, underground military projects, tunnels, embankments, fish ponds, artificial lakes and other waterproof impermeable aspects, can use foam concrete masonry or pouring, leaving out all waterproof materials, it is not only structural materials, but also waterproof materials have great advantages.

(2) Application of chloride ion erosion resistance in underground and water engineering

In the soil or water with high content of chloride ion, the base, foundation pile and bridge pier of concrete project may be damaged by chloride ion.If the outer masonry or pouring of these engineering structures of a layer of foam concrete protective layer, because the foam concrete impermeable, chloride ions will not be carried by water erosion concrete.







 

 

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