... A formwork girder (supporting ribs) is a girder in I-form made of PVC Plastic and designed for static ... especially suitable for underground and watery circumstance;3) Can be released from mold easily without any mold-release agent, quicken construction ... high-bending modulus;8) Surface fenacity, impact, abrasion-resistant;9) Can be nailed, drilled, planed, milled, processing, such as sawing ...