Gaan nga Concrete Additives | High-Performance Foaming Agents para sa Cellular Concrete
Any cementing material, including cement and magnesite, has an initial setting time, especially for the most widely used ordinary portland cement. The initial setting is mostly later than 45 minuto. If the foaming agent has poor stability, cement and other cementitious materials have not yet set, and the foam has collapsed, the foam will not be able to form pores in the concrete. Sa kinatibuk-an, the minimum requirement for foam stability is to make the foam stabilization time longer than the initial setting time of the gelling material by 10-20 minuto. Because the initial setting time of various gelling materials is not consistent, lahi usab ang mga kinahanglanon alang sa oras sa pag-stabilize sa bula. Sa kinatibuk-an, the foam stabilization time for fast gelling materials can be shorter, and the foam stabilization time for slow gelling materials should be as long as possible. Even if the same kind of gelling material has a different temperature, its initial setting time is different, ug ang pagbag-o hinungdanon kaayo. Pananglitan, ordinary silicon cement may set in less than 40 minuto sa ting-init.
But it will not set in 80 minuto sa bugnaw nga tingtugnaw sa ubos 5 ° C. Busa, it is impossible to have a uniform specific standard for the stabilization time of the foam, and it should be determined according to the situation. Aron ipahiangay ang bula sa mga panginahanglan sa lainlaing mga kondisyon sa paggamit, it should be allowed to stabilize as long as possible. Sa kinatibuk-an, the stabilization time of the foam should meet the following requirements;
1. When used in Portland cement without setting accelerator, the stabilization time should be more than 60min; the ideal maximum is more than 3h;
2. When used in fast-setting cement such as sulphoaluminate cement, taas nga alumina nga semento, puthaw aluminate semento, fast setting Portland cement, the stabilization time should be more than 30min, preferably more than 60min;
3. When used in magnesium cement, the foam stabilization time should be higher than 40min, preferably higher than 80min;
4. When used for gelling materials doped with a large amount of filler or active waste residue such as fly ash, ang oras sa pag-stabilize sa bula kinahanglan usab nga mapalawig. The more significant the amount of padding or active waste residue, mas taas ang oras sa pag-stabilize sa bula.
The specific foam stabilization time should be determined through a small test. The principle is that the mould does not collapse after pouring, the pores are not connected after formation, and the law of excessive deformation is not determined. The vital principle is that the longer the stabilization time, mas maayo.
Mas dako ang diametro sa bula, mas maayo. It should be above 1mm.
The pores have the same requirements for the pore size, as well as the requirements for the bubble diameter. Many producers and some experts have misled the pursuit of a fine foam with a pore size of 0.1mm. It is because physical foaming cannot make a foamed concrete if the foam diameter is large, and the stability of the foam is poor. The same raw materials and formula, the same equipment and technology, usba lamang ang diametro sa bula, the compressive strength of foam concrete with 1mm foam diameter is at least 20% higher than that of foam concrete with 0.1mm foam diameter. Busa, it is wrong to pursue a small bubble diameter of more than 0.1mm, which is a misunderstanding in the production of foam concrete and should be corrected.
Mas ubos ang foam bleeding rate, mas maayo, likayi ang paggamit sa milky foam.
Subong sang ginsambit kaina, foams are divided into milky foams with more water and less foam and creamy foams with more water and less foam. The milky foam is unqualified and inferior and cannot be used.
After the foam is confident, it gradually exudes water. Ang pagdugo niini adunay duha ka bahin:
1. Bleeding of foam liquid membrane. This part of the water is secreted from the liquid film. It is the water that the liquid film emits under the combined action of gravity drainage, surface tension drainage, ug fluid lamad pagkaguba drainage. Ang mas baga nga likido nga pelikula sa bula, mas taas ang pagdugo; the faster and more the foam collapses, mas taas ang pagdugo.
2. Inter-bubble water between foams. This part is water that does not form a bubble liquid film. Ang mas grabe pa sa foaming performance sa foaming agent ug sa foaming machine, the more inter-bubble water cannot create a foam liquid film. They are water that does not become air bubbles.
When the bleeding rate of the foam is very high, it will be as thin as floating juice, flowing randomly and cannot be piled up, and the amount of water in the foam is large. When this foam is added to the cement slurry, ang slurry sa semento mahimong nipis kaayo. Sa gihapon, the foam is minimal, the volume of the mud is small, and the density of the foamed concrete is very high, which is not technically desirable.
Busa, dili magamit ang milky foam. The appearance of the foam that meets the technical requirements should be sponge-like fine vesicles, piled up like white clouds and like bouncing cotton, ug dili basta-basta modagayday. Ang sulud sa tubig niini nga bula gamay ra. This shows that its foam liquid membrane bleeds little, the foam is not comfortable to rupture, adunay gamay nga tubig sa taliwala sa mga bula, ug ang gidaghanon sa mga bula mahinungdanon, ug kadaghanan sa volume kay bubbles. What needs to be emphasized here is that the sponge-like foam must be small bubbles with a bubble diameter of less than 1mm, not large bubbles of several millimetres or even tens of millimetres. Giant bubbles are easy to pile up, and they are like white clouds, pero kay dako kaayo ang diametro sa bula, kini usab dili kuwalipikado.
The requirement for low water bleeding of the foam is mainly to ensure the number of bubbles in the foam and the porosity of the foamed concrete, kana mao, to ensure the density of the foamed concrete.
Ang Cie-China.org mao ang nanguna nga foam concrete additives provider nga naghatag og concrete foaming agent, superplasticizer,foam concrete strength enhancer para sa lightweight nga kongkreto, Mga bloke sa CLC. Kung nangita ka ahente sa foaming, palihug pagbati nga gawasnon sa kontaka mi.