Job, Thomas; Saikia, B; Ramaswamy, A; Nanjunda Rao, K S(Kluwer Academic Publishers, December 1, 2005)
[+]
[-]
Abstract:
A/though steel is most commonly used as a reinforcing material in concrete due to its competitive cost and favorable mechanical properties, the
problem of corrosion of steel rebars leads to a reduction in life span of the structure and adds to maintenance costs. Many techniques have been
developed in recent past to reduce corrosion (galvanizing, epoxy coating, etc.) but none of the solutions seem to be viable as an adequate solution to
the corrosion problem. Apart from the use of fiber reinforced polymer (FRP) rebars, hybrid rebars consisting of both FRP and steel are also being
tried to overcome the problem of steel corrosion. This paper evaluates the performance of hybrid rebars as longitudinal reinforcement in normal
strength concrete beams. Hybrid rebars used in this study essentially consist of glass fiber reinforced polymer (GFRP) strands of 2 mm diameter
wound helically on a mild steel core of 6 mm diameter. GFRP stirrups have been used as shear reinforcement. An attempt has been made to
evaluate the flexural and shear performance of beams having hybrid rebars in normal strength concrete with and without polypropylene fibers
added to the concrete matrix
Description:
Materials and Structures 38 (December 2005) 857-864
Job, Thomas; Biswarup, Saikia; Phanindra, Kumar; Nanjunda Rao, K S; Ananth, Ramaswamy(Elsevier, September 20, 2006)
[+]
[-]
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
Description:
Construction and Building Materials 21 (2007) 1709–1719