Strength and serviceability performance of beams reinforced with GFRP bars in flexure

Abstract

Glass fiber reinforced polymer (GFRP) rebars have been identified as an alternate construction material for reinforcing concrete during the last decade primarily due to its strength and durability related characteristics. These materials have strength higher than steel, but exhibit linear stress-strain response up to failure. Furthermore, the modulus of elasticity of GFRP is significantly lower than that of steel. This reduced stiffness often controls the design of the GFRP reinforced concrete elements. In the present investigation, GFRP reinforced beams designed based on limit state principles have been examined to understand their strength and serviceability performance. A block type rotation failure was observed for GFRP reinforced beams, while flexural failure was observed in geometrically similar control beams reinforced with steel rebars. An analytical model has been proposed for strength assessment accounting for the failure pattern observed for GFRP reinforced beams. The serviceability criteria for design of GFRP reinforced beams appear to be governed by maximum crack width. An empirical model has been proposed for predicting the maximum width of the cracks. Deflection of these GFRP rebar reinforced beams has been predicted using an earlier model available in the literature. The results predicted by the analytical model compare well with the experimental data.

Comparative Study of Deflection Equations for FRP RC Beams

“…In the following, results from tests on 145 RC beams (Abdalla 2002, Alsayed 1998, Al-Sunna et al 2006, Barris et al 2009, Bogdanovic 2002, Benmokrane et al 1996, Cosenza et al 1997, Duranovic et al 1997, Larralde & Rodríguez 1992, Pecce et al 1998, Saikia et al 2007, Toutanji & Deng 2003, Yost et al 2003) are compared with 10 existing approaches of deflection prediction. The objective of the study was to investigate the sensitivity and the goodness of fit of the different models to the mentioned database.…”

Mechanical behavior of concrete prisms reinforced with steel and GFRP bar systems

“…The higher deformability of concrete structures reinforced with GFRP bars is also caused by the smaller bond stiffness of these bars, when compared to the actual generation of steel bars used for the reinforcement of concrete structures [7][8][9]. This aspect promotes the occurrence of smaller number of cracks (larger crack spacing) of larger crack width at serviceability limit state (SLS) conditions, when steel reinforcement is considered for comparison purposes [10][11][12].…”

Design of FRP Reinforced Concrete Beams for Serviceability Requirements

“…Adequate account of the serviceability behavior and the parameters involved in the post-cracking behavior is of major importance for the design of RC structures (Bischoff 2007;Baena et al 2011;Gribniak et al 2010;Kaklauskas et al 2012). Due to the mechanical properties of FRP materials, the Serviceability Limit States (SLS) may govern the design of FRP RC elements (ISIS Canada 2001;Matthys, Taerwe 2000;Nanni 2003;Saikia et al 2007;Rafi, Nadjai 2009). At a cross-section level, two requirements limit the SLS: stresses in materials and cracking (Eurocode 2 2004).…”