Pultrusion is a continuous molding process using fiber reinforcements with thermosetting resin matrices. Pre-selected reinforcement materials, such as fiberglass roving, mat,woven fabrics or stitched fabric, are drawn through a resin bath in which all material is thoroughly impregnated with a liquid thermosetting resin. Typical resins included polyester, vinyl esters and phenolics.

Grating components such as bearing bars and crossing bars shall be manufactured by the pultrusion,shall be of high strength and high stiffness elements having a maximum of 70% and a minimum of 65% glass content(by weight) of continuous roving and continuous strand mat fiberglass reinforcements. The finished surface of the product shall be provided with a surfacing veil to provided a resin rich surface which improves corrosion resistance and resistance to ultraviolet degradation.

Grating bearing bars shall be joined into panels, interlocked and epoxied into the proper spacing by passing a continuous ,notched cross rod or cross rods through the web of each bearing bar. The notches shall be spaced on centers to match the distance between the load bars.? A continuous keeper shall be driven behind the notched cross rod to affix it into place. Chemical bonding shall complete the assembly of the cross bar system to ensure both a mechanical and chemical lock.

Anti-slip surfacing: Grating shall be provided with a grit bonded to the surface of finishing grating product. Non-gritted surface is available upon request.