How to use carbon fiber reinforcement bridge
Development of Chinese bridge project already has a considerable scale, road traffic increasing traffic density and vehicle load increasing, roads and bridges load increasingly worse. There is a part of China before the highway bridge 2O century 8O's construction, its design load low standards, lack of common bearing capacity problems. And after 2O century 8O's construction, which has a lot of bridges to expose flaws, and some serious degradation of durability phenomenon occurs when far from reaching the design life, influence its carrying capacity and service life. Therefore, the use of appropriate technical measures reinforcement and reconstruction, recovery and increase the carrying capacity and the capacity of the bridge, extend the life of the bridge, in order to meet the needs of modern transportation has become very urgent.
Carbon fiber reinforced plastic is a carbon fiber material is made by a certain production process with a specific resin composite materials, and the mechanical characteristics of the stress strain entirely linear elastic, there is no yield point or plastic zones. Carbon fiber material has excellent physical and mechanical properties. Reinforced concrete structures in CFRP used, a soft sheet made of carbon fiber filament warp knit made of. carbon fiber cloth weaving, a large number of carbon fiber filament spread evenly along a main direction, with very little non-main direction The main direction of the carbon fiber yarn woven carbon fiber filaments connected together to form a thin primary fiber direction to the force of CFRP. CFRP tensile strength of the standard value should be greater than 3000Mpa, the elastic modulus of greater than 2.1 * l05MPa. physical synthesis material mechanical properties analysis, in order to maximize the advantages of the material itself, suitable for the C surface concrete components will be incomplete, damaged and carbonized layer portion cleaned, to the structure of dense area. Check whether there is corrosion of exposed steel, and the necessary The processing of after tick chisel, clean up and missing parts components exposed tendons repair restoration;
b) Aperture crack repair of cracks less than 0.2mm, brushing the surface with epoxy resin sealing;. crack than 0.2mm pouring with epoxy resin;
c) the member is polished smooth surface of the protruding portion, segment after the repair of the poor try to smooth the edges with a grinder fillet radius greater than 30mm of ground.;
d) cleaning polished surface of the component and make it fully dry.
3.2 bottom brushing
a) The primer of the main agent and the curing agent after a predetermined proportion of accurate weighing to release the container; mix well with a mixer; reconcile the amount of time should be within the available time runs out, whichever;
b) with a roller brush evenly brushing primer;
After C) primer curing, use sandpaper polished surface when the convex portion;
d) pay attention when the temperature is less than 5C, the relative humidity is greater than 85, the concrete surface moisture content of 8 or more, there may be no reliable condensation assurance measures are not construction.
3.3 epoxy putty to repair defects member surface
a) member dishing epoxy putty to fill part of the application, be restored to the surface smooth;
b) use epoxy putty to fill the inside corner to make it smooth.
3.4 carbon fiber sheet
a) In order to prevent damage to the carbon fiber, carbon fiber sheet in the transportation, storage, cutting and pasting process, forbidden by bending. patch before applying steel ruler and wallpaper knife cut fiber sheet according to a predetermined size, each length is generally not more than 6rn;.
b) carbon fiber connector must overlap more than 10cm, horizontal without overlapping;
c) the required proportion of blending resin main agent and a curing agent; brush evenly brushing adhesive resin with a roller; called lower coating;
d) When the patch between the carbon fiber sheets and resin try not to have air, available rollers along the fiber direction on carbon fiber sheet to this rolling, the resin infiltration of carbon fiber.
After bonding carbon fiber sheet, nature conservation need to achieve initial curing 24h, and to ensure undisturbed during curing.
It may be needed after the resin is cured reinforcement member surface, brushing refractory coating and color.