Polymer Concrete and Mortar Information
Polymer concrete and mortar are binders, compounds, and aggregate mixtures that use epoxy, polyester, vinyl ester or other polymer resin bonds. They cure or set through chemical reactions, thermoset bonds, and multiple component binder systems. Polymer concrete and mortar provides much greater corrosion resistance than conventional construction materials such as Portland cement. Polymer concrete consists of polymer cement mixed with water, a coarse aggregate such as gravel or crushed stone, and a fine aggregate or sand. Polymer mortar is a mixture of a polymer binder or clinker and a fine aggregate. Both polymer concrete and polymer mortar are used to join components and form structures. Products such as grout and caulk are used to fill gaps between tiles and bricks. Thin set materials such as dry set mortar and dry bond mortar include polymer cement and are used in coating products. Pre-cast shapes such as blocks and sheets are commonly available.
There are several chemical systems for polymer concrete and mortar. Acrylic binders provide excellent environmental resistance and fast setting times. Epoxy resins or binders exhibit high strength and low shrinkage during curing. They also provide toughness and resistance to chemical and environmental damage. Furan resins are formed from the polymerization or poly condensation of furfural, furfural alcohol, or other compounds containing a furan ring. They are commonly used in foundry binders, grinding wheels, refractories and other high-temperature applications. Polyurea resins or binders are used in place of phenolics or other formaldehyde resins in particle or fiberboard binder applications. Polyurethane provides excellent flexibility, impact resistance and durability. Other chemical systems for polymer concrete and mortar include silicone, polyester, and vinyl ester.
Polymer concrete and mortar varies in terms of basic specifications and mechanical, electrical and thermal properties. Basic specifications include set/cure time, set/cure temperature, density, and shrinkage. Density is measured as the mass per unit area. Shrinkage is expressed as a maximum percentage. Mechanical properties for polymer concrete and mortar include compressive strength, bond strength, tensile strength, and modulus of rupture (MOR). Electrical properties include electrical resistivity, dielectric strength and relative permittivity. The dielectric constant is the relative permittivity of a material compared to a vacuum or free space. Thermal properties for polymer concrete and mortar include service temperature, thermal conductivity, and the coefficient of thermal expansion (CTE), the amount of linear expansion or shrinkage that occurs in a material with a change in temperature.
Features and Applications
There are a variety of features and applications for polymer concrete and mortar. Some products are abrasion resistant, castable, chemical resistant, conductive, fiber-reinforced, sprayable, or waterproof. Other products provide protection against wear, corrosion, or electrostatic discharge (ESD). Polymer concrete and mortar is often used in electrical power, high voltage (HV), construction, and structural applications. Some products are used as fillers and sealants. Dry and wet gunning mixes (e.g., shotcrete or gunnite) load with gun-like devices to form walls. Wet ram cements have enough plasticity to allow a wet mix to be rammed or formed into place. Mortars, patching compounds and finishing cements with good troweling or trowel-on properties are also available.