Sometimes. The primary ingredient in the chemical reaction needed for autoclaved aerated concrete production is silica. The silica and other raw materials combine to form Tobermorite, a manmade version of a naturally occurring mineral. This gives AAC its unique strength-producing crystalline structure. Silica is found in many sources, such as sand, copper mine tailings, volcanic ash, and fly ash.

Yes, AAC may be used for stem walls. Stem walls should be protected against permanent exposure to water by applying waterproofing material such as bitumen coating on any surface in contact with soil. For exposed surfaces (above grade) that will be finished, use a cementitious waterproofing to improve adhesion of the finish. Autoclaved aerated concrete walls may be constructed on top of AAC stem walls, concrete slab, or concrete masonry units.

SafeCrete AAC blocks and panels with a minimum of 8" thickness are suitable for load-bearing applications, when used in accordance with our published design aids and allowable stress listings. 6'' blocks may be used for some interior loadbearing applications. Loadbearing applications require vertical cores reinforced with rebar and concrete. Code requires cores at corners, doors and windows.

No. Autoclaved aerated concrete is the European construction method that EIFS imitates; however, construction and performance are entirely different. EIFS consists of layers of polysterene insulation board, mesh, and base coats followed by an acrylic top coat. AAC is more practical, efficient and durable than EIFS:

Fly ash, particularly Class C, can effectively be used to stabilize soil for various types of construction. High calcium fly ash (Class C) acts as a good source of calcium hydroxide which "self activates", reacting with silica and alumina in the fly ash and soil to form a cementitious hydration product. In addition, C3A in fly ash (Class C) can react with sulfates to gain strength relatively quickly.

Easily. People often imagine that wiring will be a challenge due to the solid structure of AAC blocks. When they discover how versatile and workable AAC really is, they are pleasantly surprised. There are 3 standard methods for installing wiring in autoclaved aerated concrete walls. Many installers use a combination. Routing: Build the walls first. The electrician draws directly on the block to indicate where the wires will go.

The thermal performance of AAC is equivalent to R-20 insulation. AAC combines the advantages of low thermal conductivity and low air-infiltration with high thermal mass. This product is used in every climatic region of the world, from humid South America, to the dry heat of the Middle East and the severe cold of Finland. Insulation is rarely added; the walls are simply thicker. For more information on thermal performance testing, please see our Energy Efficient page.

Fly Ash is a pozzolan. A pozzolan is a siliceous and/ or siliceous and aluminous material which in itself is not cementitious but will, in the presence of moisture and temperature > 40°F (> 5C), combine with calcium hydroxide to form cementitious compounds. The major use of fly ash is as a partial replacement for cement in concrete. The amount of cement replaced depends on the fly ash type, the fly ash quality, the application and the atmospheric conditions.

Thin-bed mortar designed especially for AAC is used to install SafeCrete blocks and lintels. It is sold in ready-to-mix powder form. Thin-Bed Mortar is polymer modified Portland cement specifically designed to bond our blocks for interior and exterior wall construction. Just 1/8 inch mortar bed is needed to adhere the products. This extremely thin joint prevents heat loss and speeds installation. For best results, apply Thin-Bed Mortar with our notched trowel.

The autoclave process cures and hardens AAC, chemically changing the molecular structure to synthetic tobermorite. Autoclaving results in a stronger product that is "preshrunk" and dimensionally accurate. Non-autoclaved aerated concrete has a significantly lower strength per square inch. This newer product has not been subjected to decades of field testing in various climates. Safecrete AAC is a strong, durable time-tested product.

Fly ash is produced through the combustion of coal used to generate electricity. After coal is pulverized, it enters a boiler where flame temperatures reach up to 1500 degrees Celsius. Upon cooling, the inorganic matter transforms from a vapor state to a liquid and solid state. During this process individual, spherical particles are formed. This is fly ash. It is then collected by either using electrostatic precipitators, baghouses or a combination of both.

Typically, concrete designers use fly ash a partial replacement for portland cement at values up to 30 percent of the total cementitious composition. The use of high percentages (high volumes) of fly ash in concrete have been studied extensively over the last 15 years and the benefits have been well documented.

Fly ash is classified by the EPA as a non-hazardous product. As indicated by the MSDS, it is a relatively inert material. Fly ash is a product of coal combustion thus possesses no significant risk of fire or explosion. Fly ash is similar to sand in composition and consistency. When transporting and handling fly ash, the recommended precautions for safe handling as outlined on the product MSDS should be followed.

Answer: Fly ash is a by-product from coal fired electric power generating plants The inorganic or inderal constituents of the coal, such as clay, quartz and shale, fuse and chemically recombine during burning to produce various crystalline and glassyphases of fly ash. The fly ash is entrained in the flue gas and cools into spherical, usually hollow shaped particles.

The impact of fly ash on air entraining admixture (AEA) is primarily due to the carbon, represented as loss-on-ignition (LOI), remaining in the fly ash after combustion of the coal fuel. Due to the high rate of absorption of surfactants such as air entrainment into carbon, the loss-on-ignition generally has a positive correlation with AEA dosage demand.

By reacting with free lime to form additional binder material, the permeability of concrete made with fly ash is lower than that made without it. Since virtually all durability aspects of concrete are improved with a reduction in permeability, the use of fly ash improves concrete durability. In addition, concrete water demand is typically reduced when using fly ash, leading to a lower water/cementitious ratio thus increasing strength.

Any commercially-available roofing system may be used. When AAC roof panels are installed flat or near flat, they are typically covered with a membrane system such as built-up or EPDM. On a pitch, the panels are often covered with shingles, tile or concealed fastener metal roofs.

Augmentative/alternative communication systems (AAC) involve the use of personalized methods or devices to aid a person’s ability to communicate. There are many types and methods of AAC and most individuals use a combination of systems/devices depending on the needs of the communication situation. Unaided AAC systems are those that require no additional pieces of equipment. These include manual signing, gestures, facial expressions, pantomime, pointing, and/or eye gaze.

The structural span for floor/roof and wall panels depends on the live and dead loads and the thickness of the panel. for wall panels, the maximum structural span depends on the design load and thickness of panels. However, wall panels can be designed for almost all design loads typically required by national design codes.