AASHTO - American Association of State Highway and Transportation Officials
Scope
"These Specifications present provisions for the analysis and design of concrete-filled fiber-reinforced polymer (FRP) tubes (CFFT) for use as structural components in bridges. Design methodology presented in this specification allows CFFTs to be designed as flexural members@ axial compression members@ or members subjected to combined flexural and axial compression@ in addition to shear. CFFT bridge components may include beams@ arches@ columns@ and piles. These Specifications are not intended to supplant proper training or the exercise of judgment by the Design Professional@ and state only the minimum requirements necessary to provide public safety. The Owner or the Design Professional may require the sophistication of the design or the quality of materials and construction@ or both@ to be higher than the minimum requirements. The Design Professional shall be familiar with the provisions of the AASHTO LRFD Bridge Design Specifications@ 6th Edition (AASHTO@ 2012)@ hereafter referred to as ""AASHTO LRFD@"" and the latest interim revisions@ as well as with the design of conventional reinforced concrete structures and structures exposed to earth loading. The commentary directs attention to other documents that provide suggestions for carrying out the requirements and intent of these Specifications. However@ those documents and this commentary are not intended to be a part of these Specifications. FRP materials have emerged as an alternative material to steel reinforcement for concrete structures. They offer advantages over steel reinforcement due to their noncorrosive nature and nonconductive behavior. FRP is a also a versatile material that can be produced in many forms such as reinforcing bars@ grids@ rigid plates@ flexible sheets@ and several structural shapes@ including tubes. This specification is focused on one application of FRP in the form of tubes used as structural stay-in-place forms filled with concrete [Fardis and Khalili (1981)@ Nanni and Bradford (1995)@ Mirmiran and Shahawy (1996)@ Davol (1998)@ Burgue?o (1999)@ Fam (2000)@ Fam and Rizkalla (2001)@ Fam and Rizkalla (2002)]. Due to differences in the physical and mechanical behavior of FRP materials as opposed to steel@ particularly when used as stay-in-place structural forms@ unique guidance on the engineering and construction of bridge components using this technology is needed. "