The three main factors influencing the strength of foam concrete

The three main factors influencing the strength of foam concrete
As with normal concrete, the strength of the foam concrete is not a fixed value, different types of gelled material, dosage of cement, concrete mixture ratio, dosage of water cement ratio, foam (the volume of different quality), blowing agent, curing system and other admixtures used or not and so on all affect the strength of the foam concrete.We have to water cement ratio, and the choice of the admixture of do focus on three major factors.(if you want to directly purchase cement foaming machine or foam concrete device can be directly consulting our online customer service!)
1 the influence of water-cement ratio
In the preparation of ordinary concrete, the strength of concrete increases with the reduction of forming water cement ratio increases, but found in the foam concrete test condition is different.
1) in the slurry when liquidity rely mainly on the amount of admixture to control (that is, the slurry has good liquidity), with the decrease of the water cement ratio, strength increase,On the other hand, the decrease.Analysis: with the decrease of the water cement ratio, the free water in concrete decreases, foam concrete bibulous rate is lower, effectively increase the strength of concrete;But when the water cement ratio to reduce, due to a shortage of water demand for cement hydration can absorb the moisture in the bubble, makes the bubble burst, and thus cause the decrease in the number of closed bubbles and uniformity of concrete, which reduces the strength.
2) liquidity rely mainly on the amount of water in slurry to control, with the increase of water cement ratio, strength increase,On the other hand, the decrease.
Analyze reasons: higher forming water cement ratio, good liquidity, ensure the slurry to ensure lead foam evenly into the cement slurry and uniform distribution, so as to realize the growth of strength.On the contrary, low water cement ratio, slurry material liquidity shortage, will cause the bubble distribution, thereby reducing the strength of the concrete.
Comprehensive the above situation, the influence of water-cement ratio on strength of foam concrete are various, should be combined with the particular case is particular analysis, adjust the size of water cement ratio, uniform foam material inside the concrete structure and more closed independent air bubble is an important approach to improve the strength of foam concrete.
2 the influence of the mixing proportion
Foam concrete preparation can be individually when using cement, may also use except cement mixed material (such as silica fume, slag, fly ash, etc.), may also at the same time with fine aggregate (sand).The first kind of circumstance: using cement alone is relatively simple, the higher the strength grade of cement used, the dosage, the more preparation foam concrete strength.So, when you want to the preparation of high strength of foam concrete, the need to select high strength grade of cement.The second case: the introduction of the hybrid materials will significantly reduce the strength of foam concrete early, and little influence on the strength of late.If the strength of the fill in the appropriate excitation agent, which can effectively slow down the early strength reduced.In the actual construction often with mixed with mixed material and at the same time most of the sand, so the foam concrete mixture ratio the existence of a suitable scope, need to be determined according to the test.
3 the influence of the dosage of admixture
Foam concrete admixture in use mainly including cement intensity excitation agent, water reducing agent and foaming agent.
3.1 the foaming agent
From the preparation principle of foam concrete analysis, the use of foaming agent to introduce a large number of pores to endow them with ordinary concrete, no light, sound insulation, heat preservation, high liquidity, and other functions is the basis of the foam concrete preparation;But from the perspective of structure and mechanics, but also cause structural compactness is greatly reduced, thus reducing the strength of foam concrete.So, how to control the dosage of foaming agent can not only realize the lightweight, sound insulation, heat preservation and high liquidity, and other functions, concrete strength and not lower than expected targets at the same time is the concrete production is a new subject of research.
A lot of material can produce a bubble, but not all can produce the foam material can be used as a foaming agent.Only foam expansion is enough big, in bubble and slurry mixed membrane from damage, have enough stability, on the setting and hardening of gelled material can't afford to the harmful effects of foaming agent, is suitable for production of foam concrete.
The effects of foaming agent for foam concrete strength lies in the size of the bubble, uniformity (size uniformity and distribution uniformity), foam stability, foaming ability and so on.Requirements of foaming agent of foaming ability, low density, small unit with water, bubbles, small, uniform distribution, the side effects of the concrete.
3.2 cement strength agent
Cement intensity excitation agent mainly in the use of cement mixed material, can reduce the degree of foam concrete early strength decrease.However, using excitation agent tends to reduce the ultimate strength of foam concrete.
3.3 water reducing agent
Concrete water reducing agent to make foam concrete even under low water cement ratio will still be able to complete slurry mixed with bubble, bubble distribution in homogeneous foam concrete is prepared.So, adding the right amount of high efficiency water reducing agent is one of the important means of the preparation of high strength of foam concrete.However, because the price of water reducing agent is more expensive and in some water reducing agent and foaming agent has the opposite effect in some performance, so the types of water reducing agent and adding amount must be determined by test.