ACI 440.1R-03 Guide for the Design and Construction of Concrete Reinforced with FRP Bars.
Application for Internal FRP Reinforcement
The use of GFRP bars for reinforcing concrete bridge decks has captured some interest, particularly for the case of the replacement of the top steel mat. The idea is to eliminate one of the major causes of deterioration (i.e., the steel reinforcement embedded in the concrete region more exposed to chlorides) without significantly increasing cost of construction and without totally removing steel reinforcement.
In underground applications, FRP bars have historically been used as temporary soil anchors and, recently, have become the reinforcement of preference in ground containment walls for tunneling projects. In such projects, the main purpose of a concrete wall of which the soft-eye is part is to contain the ground allowing both the entrance and removal of the Tunnel Boring Machine (TBM). By using concrete reinforced with GFRP bars in the soft-eye region. the cutting operations are simplified due to the low transversal resistance of GFRP materials compared to steel.
Another interesting field of application that has become very common is the USC of FRP reinforcement for the RC elements that constitute the containment unit of Magnetic Resonance Imaging (MRI) equipment in hospitals. In this instance. FRP reinforcement is usd in lieu of steel for its magnetic transparency.
Proposed changes to the Third Edition
The proposed changes to the current edition of the guide that may become available in late 2005, address the topics shown below.
Compliance with the 2002 edition of the Building Code (ACI 318, 2002). The historical modification in the load factors in the 2002 version of ACI 318 required that the strength reduction factors introduced in the FRP design guide be revisited to become ACI 318-02 compliant with respect to these new load factors. The selection of the appropriate Q factors was based on reliability studies. Such studies indicated that the reliability index using the proposed Q factors was in the range of 3.5 to 4.0 for flexural members, similar to the target reliability index for steel reinforced concrete that should be 3.5 for most components except columns, for which it should be 4.0.
ACI 440.1R pdf download.