ABSTRACT
The FRP structural form, whether it is a closed or open form, may or may not be designed to support the weight of fresh concrete, depending on the project and availability of shoring systems. FRP tubes may be filled with concrete in a vertical, inclined, or horizontal position. Care must be taken to support the weight of fresh concrete until it hardens; otherwise, excessive deformation, sagging, or distortion of the tube may occur. Support platforms and shoring may be provided for hybrid slabs and beams, if necessary. Concrete may be pumped or poured in place. Some fabricators prefer to pressure pump the concrete fill into the FRP tubes, uphill against gravity as a means of eliminating air voids. As in any other application, concrete may be consolidated using electric air-powered mechanical vibrators that may be hand held or mounted on the form or the rack.
