Preparation of the Pre-Material Arrival Inspection Checklist: Verify the FRP material model, batch number, and production date; confirm the compatibility between the resin type and the curing agent; and inspect reinforcing materials-such as fiberglass cloth-to verify their areal weight and weave density. The construction environment temperature must be maintained between 15°C and 30°C, with humidity kept below 80%.
Operations must be suspended during rainy weather.
Surface preparation is carried out in three steps: Clean the concrete or metal substrate, remove any loose particles, and scrub away oil stains using acetone. Fill depressions and uneven areas with epoxy mortar; for cracks exceeding 2 mm in width, cut a V-groove and inject grout. Surface flatness is to be verified using a 2-meter straightedge, ensuring that any gaps do not exceed 3 mm. Metal surfaces must undergo sandblasting to achieve a cleanliness grade of Sa2.5, with a surface roughness of 40–70 microns. Material Cutting: Observe Warp and Weft Directions. For fiberglass cloth, allow a 10 cm overlap margin beyond the dimensions of the application surface; when applying diagonally, cut the material at a 45-degree angle. Carbon fiber cloth must *never* be folded; during storage, keep the rolls standing upright. When applying multiple layers, stagger the seams between adjacent layers by at least 30 cm; at corners, cut the material into radial strips.
Resin Mixing: Strictly Adhere to Operational Procedures. Weigh the epoxy resin and curing agent according to the proportions specified in the manufacturer's instructions. When mixing, stir in a clockwise direction along the inner wall of the container to prevent the formation of air bubbles. Discontinue use of the mixture once only one-third of its pot life (working time) remains; replace the mixing container with a fresh one every hour. Wear a protective face mask when adding accelerators, and strictly *prohibit* the intermixing of curing agents from different brands.
Reinforcement Application: Observe the Time Window. Use a brush dipped in resin to apply a longitudinal coating to the substrate surface, then immediately lay down the fiber cloth. Use a rubber squeegee to expel air bubbles, working from the center outward toward the edges. Apply the second layer of cloth before the previous layer has gelled. Ensure that each layer of resin thoroughly saturates the fiber cloth; the application is considered successful if the underlying substrate color remains visible through the fabric. In areas requiring localized reinforcement, apply cross-hatched layers-no fewer than three in total.
Curing Process: Phased Control. Observe the "tack-free" time: avoid touching the surface for 3 hours in summer conditions and 8 hours in winter conditions. Avoid subjecting the material to heavy loads or rolling pressure before it has fully cured. For three days following application, maintain the ambient temperature at no lower than 10°C. Use a Barcol Hardness Tester to verify the cure; proceed to the next stage of work only after the hardness value reaches 40 or higher.
Surface Treatment: Determining Product Lifespan. Once cured, sand the surface to remove any burrs or rough spots. Apply two coats of resin gelcoat, allowing a 12-hour interval between coats. In regions with intense UV radiation... Apply an anti-aging topcoat with a minimum thickness of 200 microns. Use an angle grinder to cut drainage channels in areas requiring a drainage slope.
Acceptance criteria shall reference standard GB502. Adhesion testing shall be conducted using the cross-cut method; no peeling is permitted along the edges of the cuts. Void detection shall be performed by lightly tapping with a wooden mallet; the area of any single void must not exceed 5 square centimeters. Thickness deviation must be controlled within ±10%. In electrical equipment zones, the TRP layer must pass insulation resistance testing.
During the maintenance phase, a maintenance record card shall be established. Once the facility is put into operation, quarterly inspections are required, with particular attention paid to checking for cracks at seams and signs of discoloration (yellowing).
In environments subject to chemical corrosion, the surface must be rinsed monthly; any residual acidic or alkaline liquids must be immediately neutralized using a sodium bicarbonate solution. For localized damage, a stepped grinding method shall be employed, ensuring an overlap width of greater than 8 centimeters between the new and existing surfaces.
Safety red lines must not be breached. Operators must wear anti-static clothing; if resin comes into contact with the skin, it must be immediately rinsed off with soap and water. Waste curing agents must be stored separately and strictly prohibited from being poured into drains or sewers. Wear a face mask when cutting fiber cloth. The work area requires mandatory ventilation, and the concentration of styrene in the air must not exceed 50 ppm. The insulated handles of power tools must be inspected weekly.
Solutions for Common Issues: If resin sagging is observed, immediately wipe it away with acetone. A whitening effect after curing is considered a normal phenomenon. During winter construction, when resin viscosity is high, it may be warmed via a water bath to 25°C before use. If wrinkles appear after applying the fiber cloth, it must be peeled off and re-laid; applying a new layer directly over the wrinkled section is strictly prohibited. If large-area blistering is discovered during acceptance inspection, the affected section must be chiseled out and redone; localized patching is not permitted.
