Development and application of foam concrete

1.1 The current application status of domestic foam concrete

In recent years, relevant departments in my country have paid more and more attention to building energy conservation and introduced relevant policies to promote its rapid development. The building energy-saving materials industry has gradually emerged with the rapid development of building energy-saving. As a building energy-saving material, foam concrete has many advantages, such as: convenient production and construction, good thermal insulation performance, a large number of closed bubbles and micropores, the ability to utilize a large amount of industrial waste, low density and good fire resistance. This material has a wide range of applications, especially in energy-saving wall materials.

1.1.1 Cast-in-place roof foam concrete insulation layer

As an energy-saving insulation material, its advantages It is easy to construct and has excellent overall thermal performance. Good water absorption and water retention properties are also its advantages. The disadvantage is that the absorbed water is used as the source of the roof structure and waterproof layer, which causes roof leakage [2].

2.1.2 Foam concrete blocks

(1) Autoclaved foam concrete bricks. In the southern part of the country, technicians mainly use the excellent properties of foam concrete blocks, which are lightweight and high in strength, to use them as filling blocks in the infill walls of building frame structures. According to incomplete statistics, the annual consumption of foam concrete blocks in Guangdong Province is more than 600,000 m3.

(2) Core-filled blocks. Due to shortcomings such as shrinkage cracking, low strength, and high water absorption, foam concrete blocks have not yet been produced and applied in a standardized manner. This product is mainly used as an exterior wall self-insulation system in the north. The exterior wall self-insulation system is one of the three main methods of energy-saving exterior wall insulation in my country. The other two methods are: interior exterior wall insulation system and exterior wall exterior insulation system. The application of core-filled block product technology can significantly improve the strength of foam concrete blocks, and at the same time, the overall thermal insulation performance has been qualitatively changed [28].

(3) Ceramsite blocks. With the continuous in-depth research efforts of domestic scholars, a new type of composite lightweight material is formed by innovatively combining lightweight aggregate and foam concrete by taking advantage of the reinforcement and shrinkage resistance of ceramsite aggregate and the consolidation of foam concrete. The combination of lightweight aggregate and foam concrete achieves complementary advantages, and the performance of composite products far exceeds the performance of a single material [29].

2.1.3 Foam concrete exterior wall insulation board

Foam concrete can be used for exterior wall insulation and fire isolation. Mainly because it is made without physical foaming and uses sulfoaluminate cement as a cementing material. In addition, it has the advantages of excellent thermal insulation, good durability and the ability to prevent fires. It also integrates foam concrete exterior wall insulation boards.

1.1.4 Foam concrete cast-in-place wall

Foam concrete is used on the exterior wall and Widely used in interior walls. For example, on-site pouring of exterior walls can achieve the effect of thermal insulation without the need for insulation layers; on-site pouring of interior walls can also achieve the effects of sound insulation, sound absorption and noise reduction. In China, technological innovations in areas such as load-bearing and non-load-bearing soundproof interior walls and on-site pouring of self-insulating exterior walls have been developed by relevant companies and widely promoted and applied.

1.1.5 Foam concrete integrated housing

Based on my country’s basic national conditions, the Ministry of Construction proceeds from reality The industrialization of housing is proposed to realize the reform of housing production methods and housing functions. In integrated housing, foam concrete has become the focus of many developers because of its self-insulating and energy-saving characteristics. It is generally a structural system composed of lightweight steel as the roof truss and panels made of foam concrete. Compared with ordinary integrated houses, this system can not only be self-insulating, but also has low cost and fast installation. It has the advantages of high speed and good earthquake resistance.

1.1.6 Foam concrete airport runway blocking system

Foam concrete is a porous structure Concrete can not only absorb the energy of shock waves, but also mitigate damage to the main material. Under the relevant technical appraisal of CAAC (Civil Aviation Administration of China), its use as a special engineering material in EMAS (Airport Runway Arresting System) has been approved. The foam concrete airport runway blocking system is the first foam concrete product with high added value and high technical content in China and is in a leading position internationally [29].

Subsequently, Wang Jianjun et al. [30] analyzed the energy absorption characteristics of lightweight foam concrete and its crushing flow stress equation, which can well describe the mechanical characteristics related to foam concrete. Failure and deformation mechanisms.

1.2 Application Progress of Foam Concrete Abroad

In recent years, some countries in Europe, America and Asia have focused on foam concrete. The excellent properties of concrete are widely used, and its application fields continue to expand in engineering construction. While the project progress is accelerated, the project quality also meets the requirements [31]. Regarding the application progress of foreign foam concrete projects, Hu Shikai, Li Yingquan and others conducted an in-depth investigation and summary [1].

1.2.1 Hole filling�Process

According to the characteristics of low cost and high fluidity of foam concrete, foam concrete is currently widely used as a filler for large voids abroad. Generally, it is widely used in places such as large oil tanks, basements of abandoned buildings, dry wells, private cellars or abandoned sewers.

1.2.2 Road and bridge construction

Foam concrete is reused in road and bridge construction, in order to reduce the risk of subsidence To reduce the lateral pressure on the structure, engineers filled the back of the bridge pier with foam concrete. In addition, it is also very suitable for use in cavities between bridge arch structures, bridge cladding and finally the bridge deck.

1.2.3 Refractory kiln

Some foreign scholars have focused on the excellent thermal insulation of foam concrete Performance, they tried to use it as a material that can withstand high-temperature fire and heat insulation and apply it in the construction of kilns. Nhi Tuan Pham [32] and others prepared foam concrete based on the geopolymer method combined with H2O2 to produce foamed fly ash. Especially when the geopolymer method is used to synthesize foam concrete, the heat resistance of the product can be as high as 1000°C. Foam concrete can be used as a refractory insulation material for kilns, opening up broad market prospects in the field of refractory insulation.

1.2.4 Offshore Drilling Platform

Under objective conditions, offshore drilling operations are often affected by vibrations And cause damage to the offshore drilling platform structure. Foam concrete materials are used abroad to pour offshore drilling platform structures to build impact-resistant layers to prevent mud pumps, drill bits, and drill pipes from falling. This is due to the light weight of foam concrete, and the second reason is that it has energy-absorbing and shock-absorbing properties due to the large amount of foam it contains.

1.2.5 Housing construction project

In view of the thermal insulation performance of foam concrete and its ability to be prefabricated and It is poured on site, so it is widely used by technicians in house construction. The main methods of application include the installation and masonry of prefabricated products, on-site pouring of roofs, on-site pouring of walls, etc. For example, foam concrete has been used in the fields of building houses, roof sloping and roof insulation in the Middle and Far East, South Africa and Russia.

1.2.6 Military Engineering

In the military field, technicians can use foam concrete structures to produce comparative Large damping and dissipation of energy are used to construct shooting ranges and underground anti-explosion tunnels. European and American countries have developed fiber-reinforced foam concrete for live-fire exercises. The main reason is that compared with ordinary concrete, foam concrete can not only make bullets less susceptible to corrosion, but also prevent bullets from being polluted by noise caused by collisions.

1.2.7 Sound Barrier Project

In daily life, traffic noise has always troubled people living on the road. nearby residents. Therefore, some foreign sound barrier projects take advantage of the high-quality sound absorption function of foam concrete and cast foam concrete walls on site to achieve sound insulation effects. </p