Composite reinforcement is the production of non-metallic reinforcement with the use of fiber materials and polymer binding agent. The successful manufacture of such armature is explained by a number of its characteristics:
- strength and elasticity values are up to 3 times higher than those of their metal counterparts;
- strength is not reduced when exposed to electromagnetic fields and low temperatures, down to -70°C;
- composite materials react weakly with aggressive chemical compounds, significantly reduced rates of exposure to corrosion;
- is not a conductor of electric current;
- low thermal conductivity of fittings;
- does not cause the effect of radio-tightness, in contrast to the metal fittings.
Basic principles of production.
For the production of composite reinforcement we need specialized equipment and a certain list of raw materials, which can be briefly described as follows:
- fibers (in the production process are subjected to tensile and compressive influences, which will determine the resistance to deformation) are basalt, or glass roving and braided filament;
- binder (create a single monolithic system, binding reinforcing fibers and protecting them from environmental factors) – resins and organic solvents.
The two most common varieties of composite reinforcement are fiberglass (GRP) and basalt-plastic (BPA). There is also mixed technology production, which has a fiberglass core and a basalt embossed rib. This structure greatly increases the adhesion of the product to other building materials. Thermosetting synthetic resins are used as binders:
- with release of reaction products – phenol-aldehyde, organosilicon;
- without release of reaction products – unsaturated, epoxy;
- combined high-temperature resistant polymers – polyimides, polybenzothiosols and other polymers.
In addition, the following are used
- to improve anti-corrosive properties – epoxy compounds;
- to enhance electrical properties – polyester compounds.
Technology and process.
The production line and equipment is organized to work according to the following algorithm:
- unwinding of fiber with its drying;
- impregnation with binding agents;
- section profile molding;
- binder polymerization.
First there is a simultaneous uncoiling and feeding of roving into the pulling equipment to equalize the tension force on the entire fiber section. Then the glass fibers are thermally dried in an infrared or electric furnace. After drying, the rod is fed into a sectional binder bath, at the outlet of which removable dies are installed for shaping the reinforcement of the required diameter, their compaction and removal of excess binder. The bar is then fed to a spooling machine, which winds the glass fibers forming the reinforcement surface profile with further drying and polymerization of the binder in electric furnaces. At the end of the process, a pulling device winds the composite rebar onto drums. After a day of cooling and curing, the product is ready for use.