Gypsum Wallboard

In terms of heat contribution from the walls, the gypsum wallboard provided complete protection to the assembly for 30 min. Even after 30 min, heat release rate from the assembly was below 200 kVV up to 60 min of exposure compared to the 600 kW from the assemblies without gypsum. The insulation also helped protect the assemblies, although not as dramatically as gypsum it reduced heat release rate between 5 and 10 min. 

Citrogypsum and borogypsum are named after the respective processes and produce sizeable quantities of by-product gypsum in certain locations. However, contaminants preclude commercial use in the gypsum wallboard industry. 

Flatwise Tensile Strength of Metal to Honeycomb Core Bonds Specification for Adhesives for Fastening Gypsum Wallboard to Wood Framing... 

Construction materials such as cement, concrete, aggregate, mineral and glass fiber insulation, and gypsum wallboard. 

Determine the overall unit thermal resistance (the ff-value) and the overall heat transfer coefficient (the /-factor) of a wood frame wall that is built around 38 mm X 90-mm (2X4 nominal) wood studs with a center-to-center distance of 400 mm. The 90-mri-wide cavity betv een the studs is filled with glass fiber insulation. The inside is finished with 13-mm gypsum wallboard and the outside with 13 mm wood fiberboard and 13-mm x 200-mm wood bevel lapped siding, rtie insulated cavity constitutes 75 percent of the heat transmission area while the studs, plates, and sills constitute 21 percent. The headers constitute 4 percent of the area, and they can he treated as studs. 

Matthews TG, Hawthorne AR, Thompson CV. 1987. Formaldehyde sorption and desorption characteristics of gypsum wallboard. Environ Sci Technol 21 629-634. 

It is obvious that flexure tests should be directly proportional to specimen width. Numerous tests on both types of machines have confirmed this. The modulus of rupture (MOR) formula predicts that flexural strength should be inversely proportional to the span. Combining these relationships we can calculate that the test on the 12 by 16 specimen should be 12/10 X 10/14 = 0.857 times the strength of the 10 by 12 specimen. This is reasonably close to the slope of 0.8 found for the correlation equation. Gypsum wallboard is not a homogeneous material as is assumed in the calculation of MOR. 

Drywall (or Gypsum Wallboard (GWB), Sheet rock or Plasterboard)-... 

Joint cement or Joint compound- A powder that is usually mixed with water and used for joint treatment in gypsum-wallboard finish. Often called "spackle" or drywall mud. 

The principal use for ground mica is as a filler and extender in gypsum wallboard joint compounds where it produces a smooth consistency, improves workability, and prevents cracking. It is also found in paints, molded rubber products including tires, and toothpaste. Mica flakes are being used as a replacement for asbestos in brake linings and clutch facings. 

In 2004, >110Mt of gypsum was produced worldwide. Within the US in 2004, 29.5 Mt of prefabricated gypsum products were sold or used, and the chart below shows the distribution of products making up this total. The average new home in the US contains >570m of gypsum wallboard. 

Gypsum wallboard. Gypsum is hydrated calcium sulfate. CaSO., 2 H O. 

Uses Wall plasters, gypsum wallboard, tiles, stucco, blocks, and moldings for building industry statues jewelry castings paper industry pharmaceuticals (plaster of Paris bandages, orthopedic and dental casts) Regulatory FDA approved for orals JP compliance... 

N,N-Dimethyl-N-tallow-N-(3-sulfopropyl)-ammonium betaine N,N-Distearyl-N-methyl-N-(3-sulfopropyl)-ammonium betaine foam builder, gypsum wallboard Ammonium capryleth sulfate... 

Lignin sulfonate gypsum treatment Aluminum sulfate gypsum wallboards Calcium sulfate hemihydrate gyroscopes Beryllium H3CCCI3 mfg. 

Numerous and diverse products incorporate casein in their formulations. These include dish-washing liquids, cosmetics, lightweight concrete, gypsum wallboards, pesticide sprays, water purifiers, self-levelling underlayments, and so on [12-14]. 

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