The introduction to the method of casting aerated concrete walls_News_Mis-aisa-The latest News,Tech,Industry,Environment

After the positive news regarding the Russian-Ukrainian negotiations, market risk aversion plunged. International oil prices retreated on the 29th after a straight line on the 28th, and precious metals also continued their fall. China’s domestic futures market was flat for the time being. At the end of the 30th, the main Shanghai gold contract was closed by 0.59%, the main Shanghai silver contract was closed by 1.46%. The main contract rose 0.77% to 690.7 yuan a barrel late in the session.

Back in international markets overnight, WTI crude oil futures briefly dipped below $100/BBL, while Brent crude hit its lowest intraday level in nearly two weeks. Spot gold briefly fell below $1,900 an ounce. COMEX gold futures closed down 1.1% at $1,918.4 an ounce. COMEX silver futures closed down 1.14% at $24.91 an ounce. “Crude oil prices have been extremely sensitive to changes in geopolitical news recently.” Traders believe that the current oil price is still in a wide range of shocks, the situation in Ukraine to bring the premium is still in place, although the market has a further decline in the drive, but should not be too bearish , recommended to wait and see for now. The Ukrainian premium is still there and there will be some volatility in the foam concrete market.

Methods of pouring aerated concrete walls can be divided into three types: pouring removable formwork, pouring without formwork and pouring sandwich wall. Among these three kinds of casting methods, moldless casting method is widely used.

The so-called casting wall without mold has mainly been born for the construction of aerated concrete walls in recent years. Because aerated concrete is particularly suitable for cast-in-place construction (such as roof insulation, underfloor heating insulation, floor cushion, filling work, etc.), people have always studied how to apply it to wall molding to exert its good physical properties. However, due to the high fluidity of aerated concrete, it is easy to cause accidents such as mold expansion and mud leakage for the high height of wall pouring. At the same time, it is difficult for closed construction. The uniformity and stability of the casting process is not easy to grasp.

In the application of wall casting technology in recent years, most constructions follow the traditional concrete construction technology, and there is no feasible construction technology that is organically combined with the technological characteristics of aerated concrete. Although the application field of aerated concrete has a history of several decades, the application field has been limited to a very small range. It remained in a primitive state. In recent years, the cast-in-place aerated concrete roof insulation has also remained at the original technical level, but the consistency of the aerated concrete has been increased. Only this upgrade requires a much-requested wall casting. It is far from sufficient. It should take into account the design of the construction organization, the process of preparing aerated concrete and its physical properties.

1. Wall foam concrete preparation technology

Pouring formwork walls without foam concrete, solving formwork expansion technology and slurry leakage is the key factor. Aerated concrete for pouring walls without formwork can be divided into aerated concrete preparation technology using pure ordinary Portland cement according to the application, and aerated concrete preparation technology with the addition of lightweight aggregates.

(1) Ordinary Portland cement foam concrete preparation technology. Ordinary Portland cement to prepare wall casting foam concrete is the most common wall casting foam concrete. The wall core generally has low eyeball resistance, but good sound insulation, good heat preservation and good fire resistance. Regardless of the type of cavity wall in which this product is poured, it has few requirements on settlement and bleeding of aerated concrete. For these two indicators, one is to choose a good foaming agent, which must have good foam stabilizing and anti-foam properties. At the same time, it must have affinity with various cements, and it is allowed to add admixtures. Foaming agents based on animal proteins and composite foaming agents are recommended. These two foaming agents are the first choice for wall molding.

(2) Preparation technology of adding lightweight aggregate foam concrete. For medium-height wall casting materials with higher requirements, it is necessary to add low-density lightweight aggregates to aerated concrete, especially part of lightweight aggregates, such as fly ash, ceramsite, polystyrene particles, perlite, vitrified microbeads, etc. However, ordinary foaming equipment cannot prepare aerated concrete with lightweight aggregates. For this reason, Nanchang Golden Concrete Construction Engineering Co., Ltd. introduced advanced equipment, which can efficiently add materials such as vitrified microbeads, polystyrene particles and perlite. Among aerated concrete, aerated concrete with the addition of lightweight aggregates has the characteristics of high strength, good crack resistance and good thermal insulation performance.

2. Pouring wall foam concrete conveying technology

Aerated concrete conveying technology is the key to successful wall pouring. As ordinary pump foaming equipment, due to its unreasonable transportation method, aerated concrete will be unstable and difficult to operate and control. Foam concrete fails to be poured into a large number of walls. The majority of casting failures are due to poor conveying techniques. Aerated concrete has some compressibility due to the large amount of air bubbles, which will cause separation and fragmentation under different flow rates and pressure environments. Unreasonable transportation methods will cause aerated concrete quality to change, and these changes will cause casting failure to some extent. After a large number of experiments, it has been found that the transport of aerated concrete should be unidirectional, low momentum, uniform and constant. Among the transport equipment hydraulic piston pump, diaphragm pump, screw pump, pipe pump and other pumps, only the latter two are close to the transport requirements of aerated concrete.

The biggest advantage of these two types of pumps is that there are no inlet and outlet valves, one-way pulse output, and no negative pulse caused by back and forth motion, which which maximizes the protection of the product’s original state. Therefore, it is better to choose a peristaltic pump for transporting aerated concrete, because the pressure of the pump can reach 2.5MPa, which is twice that of the screw pump. This is the preferred equipment within the maximum effective height range specified in the current aerated concrete industry standard.

3. Foam concrete wall formwork

Foam concrete wall casting without formwork is a composite composite of lightweight concrete slab, cement pressure slab, fiber cement slab, cement wood wool slab, calcium silicate slab and glass magnesium slab as formwork permanent and poured-in-place foam concrete. Insulated walls.

The formwork of the composite thermal insulation wall is a combination of the wall, and there is no formwork removal procedure, which simplifies the construction process, the work efficiency is higher, the construction period is shorter and foam concrete shrinkage cracks are effectively controlled. Composite heat insulation wall is a new type of self-insulating wall, which is an integrated product of wall, heat insulation and decoration.

TRUNNANO is a concrete additive supplier with more than 12 years of experience in nano-building energy conservation and nanotechnology development. We accept payment by Credit Card, T/T, West Union and Paypal. Trunnano will ship the goods to overseas customers via FedEx, DHL, by air or by sea.

If you are looking for high quality concrete additivesfeel free to Contact us and send inquiry:[email protected]

With the outbreak of the Russian-Ukrainian conflict, the market is increasingly concerned about the potential disruption of Russia’s energy supply. Geopolitical premiums have pushed up the price of crude oil and natural gas, and energy prices are expected to remain high in the near term. Affected by this, the market price of foam concrete may continue to rise.

Comments are closed.