When buildings are constructed, they are built to be weather-resistant and fire-resistant. Different kinds of materials offer varying levels of resistance, and this makes certain materials better for specific areas of construction. Gypcrete is a gypsum-based concrete that offers high levels of fire resistance because of qualities like low thermal conductivity and high resistance to heat transfer. Here is more information on how gypcrete contributes to fire resistance in buildings:
How to Determine Fire Rating and Fire Resistance
When laboratories test for fire rating, they look at the material’s ability to slow the passage of flames (integrity), limit the passage of temperature (insulation), absorb and retain heat, and the material’s thickness. The lab runs the material through fire simulations to see how the product reacts to the conditions. They look at how long it took the product to fail, the temperature at which it failed, and its load-bearing capacity at a specific temperature. The product is given a rating based on those results. Every material in construction, from metal to glass, has a fire rating.
Heat transfer is relevant when looking at fire resistance. One way that heat transfers is through conduction, which is how heat energy moves through a material. A material that has high conductivity means that heat moves through the material efficiently. Low conductivity means that heat does not move through the material quickly. Steel and copper have high conductivity while gypsum and rigid foam have low conductivity. For this reason, gypsum-based materials are often used as insulation like in gypsum-board or metal framework covering.
Why Gypsum Makes Gypcrete Fire Resistant
Gypcrete combines gypsum powder with water and sand at specific ratios. The different ratios affect gypsum’s fire resistance and its compressive strength. One reason that gypcrete is so fire-resistant is because of gypsum’s qualities. Gypsum is a cement-like material made of calcination calcium sulfate dehydrate. Gypsum by itself is brittle and has poor water resistance, so additives must be introduced to add strength, density, and water resistance, which qualities help improve fire resistance. Common additives include ceramsite (a type of sand) and perlite.
Research has been done to see how a layer of gypsum protects other materials from fire. The researchers found that concrete surrounded by gypsum improved the strength capacity of the concrete structure and minimized the effects of fire on the structure. The concrete structure with a thicker layer (20mm) of gypsum did not crack, spall, or change color when exposed to fire. Researchers determined that this was due to gypsum’s fire resistance capabilities.
How Gypcrete Is Used in Construction
Gypsum can be combined with sand and water to create concrete to be used as underlayment for flooring. It can be spread over wood and concrete subfloors and surround metal structures within a building’s framework. When gypcrete is installed on top of a subfloor, it adds fire resistance and insulation qualities. These qualities help maintain a steady indoor temperature and improve the integrity of the flooring. If a fire were to start near or on the building, the gypcrete in the flooring and walls would slow the transfer of heat and flames, lowering the possibility of the structure collapsing. This makes gypcrete and other gypsum-based materials indispensable in the construction industry.
When gypcrete is used in flooring, the ratio of sand to water to gypsum powder will influence how effective the gypcrete is for fire resistance and how much compressive strength the flooring will have. The mixture ratio, the surface the gypcrete is poured on, and the thickness of the gypcrete will determine how long the structure will hold up against fire. Some materials can last for an hour and others will last up to four hours.
Use Gypcrete for Your Construction Project
Gypsum-based materials have been heavily researched and found to have high fire resistance because of gypsum’s low conductivity and good insulation properties. These qualities make gypsum-based concrete useful in building construction. Gypcrete installers provide different kinds of gypcrete that work well in varying areas of construction. Get in touch with installers to learn more about how gypsum-based concrete can benefit your project.
