Polymer concrete

Polymer concrete is part of group of concretes that use polymers to supplement or replace cement as a binder. The types include polymer-impregnated concrete, polymer concrete, and polymer-Portland-cement concrete. Polymers in concrete have been overseen by ACI Committee 548 since 1971.^{[citation needed]}

Composition

In polymer concrete, thermosetting resins are used as the principal polymer component due to their high thermal stability and resistance to a wide variety of chemicals. Polymer concrete is also composed of aggregates that include silica, quartz, granite, limestone, and other high quality material. The aggregate must be of good quality, free of dust and other debris, and dry. Failure of these criteria can reduce the bond strength between the polymer binder and the aggregate.

Uses

Polymer concrete may be used for new construction or repairing of old concrete. The adhesion properties of polymer concrete allow patching for both polymer and cementitious concretes. The low permeability and corrosive resistance of polymer concrete allows it to be used in swimming pools, sewer structure applications, drainage channels, electrolytic cells for base metal recovery, and other structures that contain liquids or corrosive chemicals. It can also be used as a replacement for asphalt pavement, for higher durability and higher strength.

Advantages

Advantages of polymer concrete include:

• Rapid curing at ambient temperatures
• High tensile, flexural, and compressive strengths
• Good adhesion to most surfaces
• Good long-term durability with respect to freeze and thaw cycles
• Low permeability to water and aggressive solutions
• Good chemical resistance
• Good resistance against corrosion
• Lighter weight (only somewhat less density than traditional concrete, depending on resin content in the mix)
• May be vibrated to fill voids in forms
• Allows use of regular form-release agents (in some applications
• Dielectric

Disadvantages

Some safety issues arise out of the use of polymer concrete. The monomers can be volatile, combustible, and toxic. Initiators, which are used as catalysts, are combustible and harmful to human skin. The promoters and accelerators are also dangerous.^{[citation needed]}

Polymer concretes also cost significantly more than conventional concrete.^{[citation needed]}

Specifications

Following are some specification examples of the features of polymer concrete:

Density kg/m3	Compressive strength MPa
2260	37

Applications

Polymer concrete has been in use for many years. Beginning in the mid 1950's polymer concrete has been used in Sewer Manholes, Pipe, flat wall structures and tanks. It has not been widely adopted due to the high costs and manufacturing difficulty in traditional manufacturing techniques. Although major progress and significant cost savings have recently been discovered and slowly being implimented into the marketplace.

A growing market for corrosive resistant Polymer concrete sewer manholes is revitalizing precast polymer concrete. This is allowing for competition and innovation making the products more avaliable and affordable. Used in both new construction and rehabilitaion of manholes, polymer concrete carries a corrosive resistant property to toxic and corrosive sewer gases and bacteria in the systems. Polymer concrete is seen as a solution to corrosion resistance in sewer manholes just as PVC has been found as a affordable and lasting solution in smaller diameter sewer pipe. Polymer conrete structures also require no coating or welding of PVC protected seams in traditional concrete structures.