Thursday, July 28, 2011

AAC Stock Area



AAC warehouse ; just put the finish product to the open area ( no roofing ).


Monday, July 25, 2011

AUTOCLAVE

Autoclave is the key equipment in the production of aerated concrete and autoclaved brick. Autoclave is a principle and cylindrical device made of steel, and has the advantages of good quality and reliable performance.

Purpose of Autoclave
The autoclave is applicable for curing the cut body under high temperature and high pressure, and is also applicable for curing the autoclaved brick under high temperature and high pressure.

Structural Features of Autoclave
Autoclave is a principle and cylindrical device made of steel, the cover is made of a whole piece of pressed 16 Mn steel board, and the flanges of cover and body adopt a whole piece of forged and processed 16 Mn steel board. The welding lines of pressed components are subjected to heat treatment and strict non destructive test. The max design pressure reaches 1.65-1.8 Mpa.

What Is Silica Sand ?


Silica sand is one of the most common varieties of sand found in the world. It is used for a wide range of applications, and can be purchased from various suppliers throughout the world. Silica sand is used in industrial processing, to make glass, as fill, and to create molds and castings.
Sand is the general term for broken down granules of minerals or rocks, technically between about one-sixteenth of a millimeter to two millimeters in diameter, falling between silt and gravel in the spectrum of sizes. There are many varieties of sand in the world, each with their own unique composition and qualities. The white sandy beaches of iconic tropical destinations, for example, are made up primarily of limestone that has been broken down, while many black sands are either volcanic in origin or contain magnetite. Other sands have high levels of iron in them, and so are rich and yellow in color.
The most common mineral in the Earth’s continental crust is quartz, and most silica sand is made up of broken down quartz crystals. Silica is another name for silicon dioxide, SiO2, of which quartz is a specific latticed structure. So silica sand is quartz that over the years, through the work of water and wind, has been broken down into tiny granules. These granules can be used for many different purposes, and can be found in most non-tropical regions of the world.
Silica sand is used throughout the world, and in so many different ways it is hard to imagine a world without it. From water filtration, to glass manufacture, to industrial casting, to sand blasting, to producing concrete, to adding texture to slick roads, silica sand impacts every aspect of daily life. Many industrial suppliers carry silica sand in bulk quantities, while some smaller household stores sell it in smaller amounts for home or home construction use. One of the major uses of silica sand in the modern world is as an ingredient in industrial concrete. Silica sand produces the bulk of a great deal of concrete, although some concrete bypasses its use for safety and strength reasons. At industrial scales, silica sand can cost less than $0.50 US Dollars (USD) per pound, while the consumer rate is around $1.50 USD per pound.

Quartz silica, also known as crystalline silica or crystalline silicone dioxide, is a mineral that is found in nature. It is one of the most abundant minerals on earth, and there are hundreds of different varieties of it, some of which are gemstones. The molecular structure of quartz silica is unusual and allows stones composed of the material to grow to large sizes over time.
One of the most common minerals on earth, quartz silica can be found on every continent and in every kind of environment. The mineral grows as layers of silicone dioxide are deposited on a seed crystal or on a small cluster of silicone dioxide molecules. These crystals are found in many different types of rocks, including igneous rock, like granite, and sedimentary rock, such as shale. Quartz is extremely hard, which means that it often outlasts the stone that it was originally found in. These stones often weather away over time, freeing the crystals.
Quartz silica has a very particular structure that is only found in one other type of mineral on earth. The molecules of silicone dioxide are arranged in sets of four that twist around like a corkscrew. The structure of the molecules in this mineral makes it relatively difficult to cut, though many varieties can be carefully worked into the common gemstone cuts. Over time, these crystals can grow to lengths of several meters, though these are rare.
There are many different forms of quartz silica that are found in nature. Citrine, amethyst, rose quartz, and smoky quartz are some of the common varieties of the mineral. Though the color and look of all of these stones varies considerably, they are all made up of silicone dioxide and are all crystalline forms of this compound. Other stones, such as onyx, agate, and bloodstone are also forms of silicone dioxide, though they are made up of both quartz and monganite, which have different crystalline structures.
Rock collectors prize quartz silica for the many varieties that they can find. Examining elements of the stones such as color, clarity, shape, and size can yield hundreds of different types of quartz, no two exactly alike. In computer science, extremely pure specimens of quartz silica are used to create certain electrical components, including timing devices. Quartz is also commonly used in watches because its resonance frequency remains stable for long periods of time and under many different environmental conditions

How To Making Light Concrete - AAC

Aerated autoclaved concrete is manufactured by mixing a silica rich material such as fine ground sand or fly ash, cement, a sulfate source such as gypsum, quicklime, a rising agent and water.



In a first chemical reaction ;

The quicklime reacts with the water to form heat and calcium hydroxide. The calcium hydroxide, in turn, reacts with the water and rising agent to form hydrogen gas which expands the concrete mix to about twice its original volume, or more. Similar to bread rising, the mix expands into a porous mass. After expansion has occurred, the porous mass is cut to a desired size and shape



Second reaction ;

In autoclave to build strength, rigidity and durability with the cement component serving to harden the mass.


More information : please contact to Frangky





Saturday, July 23, 2011

AAC Introduction

Autoclaved aerated concrete (AAC) is a popular building material in use all over the
world. It has a 50-year history of successful use in all environments for all types of buildings (Wittmann, 1983, 1992). Two types of AAC are commonly being manufactured. Both use combinations of lime and Portland cement mixed with either ground quartz sand or Class F fly ash. AAC offers a wide array of positive attributes vis à vis concrete block and insulated wood 2 frame construction for residents of North America. However, the final decision to use AAC instead of more conventional building materials will ultimately hinge on the cost of making, transporting and assembling AAC at its point of use. To date, even after intensive lobbying by the AAC industry, the North American consumer has not made the switch.

In fact two of the original German manufacturers have pulled up stakes and gone home.
Environmentally speaking, AAC is less material and energy consumptive than many
construction materials. It is estimated that the total amount of energy consumed during
production (including energy invested in making Portland cement, lime and rising agent) is on the order of 1000 MJ/m3 (Aroni et al., 1993). It achieves this status because some AAC manufacturers already use fly ash and other industrial waste in their formulations coupled with the traditional low energy processing in an autoclave..

The introduction of a cellular structure during initial formation of the AAC allows one to produce 3-4 m3 of AAC from 1 m3 starting materials (Aroni et al., 1993). When making lime-silica AAC, ground quartz flour is mixed with lime. Portland cement and water to make a thin slurry. At the last moment, rising agent is added to the mixture. The mixture is then transferred to a massive steel mold wherein the slurry begins to foam. After 45 minutes or so, the AAC “cake” occupies approximately 3-4 times as much space as it did when it was first poured. It has also developed enough green strength to be demolded, cut with wire saws to a variety of shapes (blocks and/or panels), and placed in autoclave. After treating in autoclave the block or panel is removed and ready for use. Densities are on the order of 400-600 kg/m3 and compressive strengths range from 2 to 5 MPa (Aroni et al, 1993).

More information please contact to Frangky