Views: 220 Author: Site Editor Publish Time: 2021-03-18 Origin: Site Inquire
Have you ever bought the AAC products? Do you really understand AAC products? Generally speaking, AAC stands for autoclaved aerated concrete; and AAC also can be divided into two main products according to different raw materials, one is called autoclaved sand aerated concrete and the other is called autoclaved ash aerated concrete.
Table of Content
The difference between the sand AAC and ash AAC
Autoclaved sand aerated concrete is a light porous silicate product made of silica sand, cement, and lime as raw materials, aluminum powder as a foaming agent, through the processes of ingredients, mixing, pouring, pre-curing, cutting, and curing under the high temperature (180℃~200℃) high pressure (10 to 12 standard atmospheric pressure).
Autoclaved sand aerated concrete block
Autoclaved sand aerated concrete block
Autoclaved sand aerated concrete panel
Autoclaved ash aerated concrete is a new building material made of fly ash, lime, and cement as raw materials, aluminum powder as a foaming agent, through the processes of ingredients, mixing, pouring, pre-curing, cutting, and curing. The production technology is basically the same as the sand AAC.
Autoclaved ash aerated concrete block
Autoclaved ash aerated concrete block
The main raw material of sand AAC is fine-grained silica sand (SiO2 content is over 90%); the main raw material of ash AAC is fly ash (SiO2 content is about 48%).
The color of sand AAC is grayish-white, or white with a little yellow; the color of ash AAC is navy blue, or grey with a little dark blue.
Compared with ash AAC, the appearance of sand AAC is smoother and has higher dimensional accuracy. (Margin of error of sand AAC is ±3mm; ash AAC is ±4mm)
In general, under the same condition of dry density, sand AAC has higher compressive strength than the ash AAC (the compressive strength of sand AAC is 3.5~7.5Mpa; ash AAC is 2.5~5.0Mpa); Under the same condition of compressive strength, the pore structure of sand AAC is more complete and uniform than that of ash AAC and has better thermal insulation performance.
The dry shrinkage of sand AAC is smaller than that of ash AAC; the sand AAC wall system barely has cracks. On the contrary, the ash AAC wall system relatively easy to has cracks. (The dry shrinkage of sand AAC is ≤0.5mm/m, which is measured by standard method; in the natural state of drying, the value is even smaller by nearly ≤0.1mm/m; ash AAC is about 0.6~0.8mm/m).
Compared with ash AAC, the ingredient of sand AAC needs more cement.
The frost resistance of sand AAC is stronger than that of ash AAC. Therefore, sand AAC can be used as an external wall block.
Sand AAC has better toughness than ash AAC, and the brittleness of ash AAC is better. Therefore, the edges and corners of ash AAC are more easily broken than those of sand AAC. Sand AAC has a variety of applications, such as internal wall system, external wall system, roof system, and floor system; it not only can be used to produce AAC block but also can be used to produce AAC panel. The use of ash AAC is limited, only suitable for internal wall filling.
The sand needs to be mined; it consumes energy during mining and also consumes a large amount of energy during production (need to grind), so the cost of producing sand AAC is higher than the cost of producing ash AAC. Besides, fly ash is the waste discharged from the power plant, the production of ash AAC is a waste utilization, the cost is bound to be lower, and in line with the national environmental protection policy.
In addition, Ash AAC is slightly radioactive, because the composition of fly ash contains Ra, Th, K, U, etc.
Overall, the sand AAC has better performance; and the Ash AAC is more economical.