Sika SikaWrap-300 C

Sika SikaWrap-300 C is TRSC's default CFRP wrap fabric where externally-bonded wrap reinforcement is the appropriate engineering intervention. The product is selected for three job profiles: (1) shear strengthening of beams where full or U-wrap CFRP is required to increase shear capacity beyond the existing stirrup contribution; (2) column confinement where the CFRP wrap acts as a passive lateral reinforcement, increasing column compressive strength and ductility under axial load; (3) end-anchorage U-wraps to CarboDur S flexural plate installations, where the U-wrap prevents premature debonding at the plate ends. The product earns its specification slot over alternative CFRP fabrics on three grounds: it is part of the Sika CarboDur system (compatible with CarboDur S plate, Sikadur-30 LP plate adhesive and Sikadur-330 LP fabric resin), which simplifies system specification on hybrid plate-and-wrap strengthening designs; it carries documented characteristic properties for ULS design under FIB Bulletin 14; and the wet lay-up installation method is the long-established Australian standard for CFRP wrap, with Sika installer training widely available. The most common specification pitfalls TRSC encounters in the field are: (1) substrate corner preparation — CFRP fabric is brittle in transverse tension and cannot be bent around a sharp corner without splitting; the substrate corners must be ground to a minimum 25 mm radius before fabric application; field installations that omit this step produce a wrap that splits at the corners on first loading; (2) impregnation control — the dry fabric must be fully impregnated with Sikadur-330 LP resin to develop the design fibre tension; under-impregnated fabric leaves dry fibres that contribute no strength at strain; over-impregnated fabric increases laminate thickness without strength gain and complicates surface coating; field crews require training and consistent supervision to deliver consistent impregnation; (3) overlap detailing — CFRP fabric joints require a minimum 100-150 mm overlap in the fibre direction, with the overlap fully impregnated and consolidated; field installations frequently under-detail joints and the consequence is failure at the joint before design strain is reached. TRSC strengthening designs include the substrate corner preparation specification, the impregnation acceptance criterion (visual transparency of the wet fabric), the joint overlap detail, and a witness hold point for the first wrap installation.