AAC Block - FAQ ( प्रश्न-उत्तर )
FAQ for AAC Blocks masonry. Autoclaved aerated concrete (AAC) is a lightweight, precast, foam concrete building material suitable for producing concrete masonry unit (CMU) like blocks. Composed of quartz sand, calcined gypsum, lime, cement, water and aluminum powder, AAC products are cured under heat and pressure in an autoclave. Invented in the mid-1920s, AAC simultaneously provides structure, insulation, and fire- and mold-resistance. Forms include blocks, wall panels, floor and roof panels, cladding (façade) panels and lintels. AAC products may be used for both interior and exterior construction, and may be painted or coated with a stucco or plaster compound to guard against the elements, or covered with siding materials such as veneer brick or vinyl siding. In addition to their quick and easy installation, AAC materials can be routed, sanded, or cut to size on site using standard power tools with carbon steel cutters. AAC is a highly thermally insulating concrete-based material used for both interior and exterior construction. Besides AAC's insulating capability, one of its advantages is quick and easy installation, because the material can be routed, sanded, or cut to size on site using standard power tools with carbon steel cutters. AAC is well suited for high-rise buildings and those with high temperature variations. Due to its lower density, high-rise buildings constructed using AAC require less steel and concrete for structural members. The mortar needed for laying of AAC blocks is reduced due to the lower number of joints. Similarly, the material required for rendering is also lower due to the dimensional accuracy of AAC. The increased thermal efficiency of AAC makes it suitable for use in areas with extreme temperatures, as it eliminates the need for separate materials for construction and insulation, leading to faster construction and cost savings. Even though regular cement mortar can be used, most of the buildings erected with AAC materials use thin bed mortar in thicknesses around 3.2 millimetres (1⁄8 in), depending on the national building codes. AAC materials can be coated with a stucco or plaster compound to guard against the elements, or covered with siding materials such as brick or vinyl. Unlike most other concrete applications, AAC is produced using no aggregate larger than sand. Quartz sand, calcined gypsum, lime (mineral) and/or cement and water are used as a binding agent. Aluminum powder is used at a rate of 0.05%–0.08% by volume (depending on the pre-specified density). In some countries, like India and China, fly ash generated from coal-fired power plants, and having 50–65% silica content, is used as an aggregate. When AAC is mixed and cast in forms, several chemical reactions take place that gives AAC its light weight (20% of the weight of concrete) and thermal properties. Aluminum powder reacts with calcium hydroxide and water to form hydrogen. The hydrogen gas foams and doubles the volume of the raw mix creating gas bubbles up to 3 millimetres (1⁄8 in) in diameter. At the end of the foaming process, the hydrogen escapes into the atmosphere and is replaced by air. When the forms are removed from the material, it is solid but still soft. It is then cut into either blocks or panels, and placed in an autoclave chamber for 12 hours. During this steam pressure hardening process, when the temperature reaches 190 °C (374 °F) and the pressure reaches 800 to 1,200 kPa (8.0 to 12.0 bar; 120 to 170 psi), quartz sand reacts with calcium hydroxide to form calcium silicate hydrate, which gives AAC its high strength and other unique properties. Because of the relatively low temperature used, AAC blocks are not considered to be a fired brick but a lightweight concrete masonry unit. After the autoclaving process, the material is ready for immediate use on the construction site. Depending on its density, up to 80% of the volume of an AAC block is air. AAC's low density also accounts for its low structural compression strength. It can carry loads of up to 8,000 kPa (1,200 psi), approximately 50% of the compressive strength of regular concrete. In 1978, the first AAC material factory - the LCC SIPOREX- Lightweight Construction Company - was opened in the Persian Gulf state of Saudi Arabia, supplying Gulf Cooperation Council (GCC) countries with aerated blocks and panels. Since 1980, there has been a worldwide increase in the use of AAC materials. New production plants are being built in Australia, Bahrain, China, Eastern Europe, India and the United States. AAC is increasingly used worldwide by developers, architects, and home builders. एएसी ब्लॉक के इस एपिसोड में एएसी ब्लॉक की चिनाई के महत्वपूर्ण पहलुओं पर विस्तृत चर्चा एवं सवाल-जवाब|
FAQ for AAC Blocks masonry. Autoclaved aerated concrete (AAC) is a lightweight, precast, foam concrete building material suitable for producing concrete masonry unit (CMU) like blocks. Composed of quartz sand, calcined gypsum, lime, cement, water and aluminum powder, AAC products are cured under heat and pressure in an autoclave. Invented in the mid-1920s, AAC simultaneously provides structure, insulation, and fire- and mold-resistance. Forms include blocks, wall panels, floor and roof panels, cladding (façade) panels and lintels. AAC products may be used for both interior and exterior construction, and may be painted or coated with a stucco or plaster compound to guard against the elements, or covered with siding materials such as veneer brick or vinyl siding. In addition to their quick and easy installation, AAC materials can be routed, sanded, or cut to size on site using standard power tools with carbon steel cutters. AAC is a highly thermally insulating concrete-based material used for both interior and exterior construction. Besides AAC's insulating capability, one of its advantages is quick and easy installation, because the material can be routed, sanded, or cut to size on site using standard power tools with carbon steel cutters. AAC is well suited for high-rise buildings and those with high temperature variations. Due to its lower density, high-rise buildings constructed using AAC require less steel and concrete for structural members. The mortar needed for laying of AAC blocks is reduced due to the lower number of joints. Similarly, the material required for rendering is also lower due to the dimensional accuracy of AAC. The increased thermal efficiency of AAC makes it suitable for use in areas with extreme temperatures, as it eliminates the need for separate materials for construction and insulation, leading to faster construction and cost savings. Even though regular cement mortar can be used, most of the buildings erected with AAC materials use thin bed mortar in thicknesses around 3.2 millimetres (1⁄8 in), depending on the national building codes. AAC materials can be coated with a stucco or plaster compound to guard against the elements, or covered with siding materials such as brick or vinyl. Unlike most other concrete applications, AAC is produced using no aggregate larger than sand. Quartz sand, calcined gypsum, lime (mineral) and/or cement and water are used as a binding agent. Aluminum powder is used at a rate of 0.05%–0.08% by volume (depending on the pre-specified density). In some countries, like India and China, fly ash generated from coal-fired power plants, and having 50–65% silica content, is used as an aggregate. When AAC is mixed and cast in forms, several chemical reactions take place that gives AAC its light weight (20% of the weight of concrete) and thermal properties. Aluminum powder reacts with calcium hydroxide and water to form hydrogen. The hydrogen gas foams and doubles the volume of the raw mix creating gas bubbles up to 3 millimetres (1⁄8 in) in diameter. At the end of the foaming process, the hydrogen escapes into the atmosphere and is replaced by air. When the forms are removed from the material, it is solid but still soft. It is then cut into either blocks or panels, and placed in an autoclave chamber for 12 hours. During this steam pressure hardening process, when the temperature reaches 190 °C (374 °F) and the pressure reaches 800 to 1,200 kPa (8.0 to 12.0 bar; 120 to 170 psi), quartz sand reacts with calcium hydroxide to form calcium silicate hydrate, which gives AAC its high strength and other unique properties. Because of the relatively low temperature used, AAC blocks are not considered to be a fired brick but a lightweight concrete masonry unit. After the autoclaving process, the material is ready for immediate use on the construction site. Depending on its density, up to 80% of the volume of an AAC block is air. AAC's low density also accounts for its low structural compression strength. It can carry loads of up to 8,000 kPa (1,200 psi), approximately 50% of the compressive strength of regular concrete. In 1978, the first AAC material factory - the LCC SIPOREX- Lightweight Construction Company - was opened in the Persian Gulf state of Saudi Arabia, supplying Gulf Cooperation Council (GCC) countries with aerated blocks and panels. Since 1980, there has been a worldwide increase in the use of AAC materials. New production plants are being built in Australia, Bahrain, China, Eastern Europe, India and the United States. AAC is increasingly used worldwide by developers, architects, and home builders. एएसी ब्लॉक के इस एपिसोड में एएसी ब्लॉक की चिनाई के महत्वपूर्ण पहलुओं पर विस्तृत चर्चा एवं सवाल-जवाब|