What is Foam Lightweight Soil? What is the reason why the foam light soil is too dense

Foam cement lightweight soil is a foaming agent that will be used by the foaming system of the bubble machine.

It is fully foamed by mechanical means, and the foam is evenly mixed with the cement slurry, and then the cast-in-place construction or mold forming is carried out through the pumping system of the foaming machine, and a new type of lightweight thermal insulation material containing a large number of closed pores is formed by natural curing.

The characteristics of foam cement lightweight soil: lightness, integrity, low elasticity and shock absorption, compressive resistance, water resistance, durability, and fast construction speed.

This is a new type of scientific and technological engineering material, mainly used for subgrade filling, soft foundation treatment, bridgehead treatment, highway expansion, abutment back filling applications, etc. Lightweight materials refer to materials made of artificial materials with lower apparent density and higher strength, the main characteristics of which are that the apparent density is smaller than that of ordinary soil, and the strength and deformation characteristics can reach or even exceed good soil. Foam cement lightweight soil has the characteristics of good fluidity, hydraulic hardness, construction and economy, and has a very broad application prospect.

The basic properties of foam cement lightweight soil materials are generally adjusted in the range of 500 1500kg m3; Its compressive strength can be adjusted within a range; Its liquidity index, that is, the degree of expansion, is about 180 20mm. The apparent density increased by about 8 after immersion. In practical application, its own compressive subsidence is negligible, and its shear strength is about 1 3 of the uniaxial compressive strength.

If the repeated fatigue load is controlled at about 50 of the uniaxial compressive strength, its influence on the strength is negligible. For the specific theory of foam cement lightweight soil for embankment design, the design should consider the back earth pressure, water pressure, self-weight, upper load, horizontal earth pressure, buoyancy, force, impact force and other factors and the safety factor under different conditions, and the stability analysis items include local stability analysis and overall stability analysis

1. Bulk density characteristics. The bulk density of foam light soil is smaller than that of general civil materials, and its size is mainly controlled by the mix ratio, age and environmental conditions. In the process of initial formation, solidification and use, the bulk density of foam light soil is changing, usually, the bulk density of foam light soil in the flow state just formed by the production equipment before the initial setting is the largest, with the extension of the aging period after solidification, when there is no water infiltration, the free water in the foam light soil will be gradually lost, resulting in the gradual reduction of its bulk density.

The single pouring height will affect the capacity and weight of the foam light soil, and the single pouring height should not be too large, and it is appropriate not to exceed 1m; And water can cause the bulk density of foam light soil to increase, when using foam light soil in the possibility of long-term situation, the influence of bulk density after water should be considered, or take necessary waterproof measures to avoid the increase of bulk density.

2. Permeability characteristics. Under the action of a certain water pressure, the foam light soil will produce infiltration, and its infiltration path is the pores that communicate with the outside. The permeability of foamed lightweight soil was studied by measuring the permeability coefficient, and the magnitude of the permeability coefficient also reflected the degree of communication between the internal pores and the outside.

The permeability coefficient of foam lightweight soil increases with the decrease of bulk density.

3. Drying shrinkage macro modification characteristics. The shrinkage coefficient of foam lightweight soil is affected by the ratio of sand to cement mass (s c), and decreases nearly linearly with the increase of s c value.

Foam cement lightweight soil is a new type of lightweight thermal insulation material containing a large number of closed pores formed by natural curing by fully foaming the foaming agent by mechanical means through the excavation and anti-aging foaming system of the bubble machine, and evenly mixing the foam and cement slurry, and then carrying out cast-in-place construction or mold forming through the pumping system of the foaming machine.

The characteristics of foam cement lightweight soil: lightness, integrity, low elasticity and shock absorption, compressive resistance, water resistance, durability, and fast construction speed.

Hello friends, to improve the toughness of foam lightweight soil, you can start from the following aspects:1Use the right additives:

Additives can improve the mechanical properties of the soil and increase the compressive strength and toughness. Common liquid preparation additives include polypropylene fiber, cellulose ester, methylcellulose, etc. 2.

Adjust soil composition: Factors such as the proportion, particle size distribution, and moisture content of perlite, expanded perlite, and clayey soils in foamed light soils can affect toughness. Therefore, the toughness of foamed lightweight soil can be improved by adjusting these factors.

3.Use of binders: The use of suitable binders can enhance the cohesion and cohesion of the foamed lightweight soil, thereby improving the toughness of the foamed lightweight soil.

4.Reasonable construction: During construction, it is necessary to pay attention to controlling the penetration and compaction of the soil layer, so that the interior of the foam lightweight soil is bonded to each other, and its toughness is improved without affecting the density of the bulk body.

In summary, improving the toughness of land-carrying foam lightweight soil needs to be considered and adjusted from many aspects, and needs to be analyzed and treated in combination with the specific situation.

The bubble light soil can not be directly load-bearing, because the bubble light soil is used on the main structure.

Bubble concrete is a new type of lightweight insulation material containing a large number of closed pores formed by natural curing by fully foaming the foaming agent through the foaming system of the bubble machine, and mixing the foam and cement slurry evenly, and then carrying out on-site pouring construction or mold forming through the pumping system of the foaming machine. It belongs to the bubble-like thermal insulation material, and the outstanding feature is to form a closed foam hole inside the concrete, so that the concrete is lightweight and insulated.

Feature 1) Lightweight: The dry bulk density is 300-1600kg m3, which is equivalent to about 1 5 1 8 of ordinary cement concrete, which can reduce the overall load of the building.

2) Integrity: It can be poured on site, tightly combined with the main body, and does not need to leave boundary joints and ventilation pipes.

3) Low elastic shock absorption: The porosity of bubble mixed light soil makes it have a low elastic modulus, so that it has a good absorption and dispersion effect on impact loads.

4) Compressive strength: The compressive strength is.

5) Water resistance: cast-in-place bubble mixed light soil has less water absorption, relatively independent closed bubbles and good integrity, so that it has a certain waterproof performance.

6) Durability: the same as the life of the main project.

7) Fast construction speed: only need to use a simple machine to realize automatic operation, can achieve 800 meters of long-distance transportation, the workload is 150-300m3 working days.

8) Environmental protection: The raw materials required for bubble mixed lightweight soil are cement and foaming agent, and the foaming agent is neutral, which does not contain harmful substances such as benzene and formaldehyde, which avoids environmental pollution and fire hazards.

9) Economy: low comprehensive cost.

According to the definition of CECS249-2008 "Technical Specification for Foam Lightweight Soil in Place", foam lightweight soil is "a lightweight material formed by physical hardening of the aqueous solution of foaming agent prepared into foam by physical methods, mixed and stirred with cement-based cementitious materials, water and optional component aggregates, admixtures and admixtures in a certain proportion, and hardened by physical and chemical action".

Bubble mixed lightweight soil is a new type of lightweight insulation material containing a large number of closed pores formed by natural curing by fully foaming the foaming agent by mechanical means through the foaming system of the bubble machine, and evenly mixing the foam with cement slurry, and then carrying out cast-in-place construction or mold forming through the pumping system of the foaming machine.