Ductility enhancement of geopolymer concrete columns using fibre-reinforced polymer confinement

Confinement of reinforced concrete columns by circumferential fibre reinforced polymer (FRP) wraps is a promising application of FRP materials for structural strengthening and seismic upgrading of deteriorated or under-strength members. However, if this technique is to be used in buildings, parking garages, and industrial structures, then the ability of FRP materials and FRP-wrapped columns to withstand the effects of fire must be demonstrated and evaluated. This paper presents the results of parametric studies conducted using a previously presented and partially validated numerical fire simulation model to investigate the effects of a number of parameters on the fire behaviour of FRP-wrapped reinforced concrete columns. It is demonstrated that appropriately designed and adequately protected FRP-wrapped reinforced concrete columns are capable of achieving fire endurances equivalent to conventionally reinforced concrete columns. Furthermore, this study also suggests that a holistic approach to the fire design of FRP-wrapped members is required, rather than an approach based on the specific performance of the FRP materials. Design recommendations for the fire-safe design of FRP-wrapped concrete columns are presented and discussed.Key words: reinforced concrete, rehabilitation, strengthening, fibre reinforced polymer, fire endurance, fire insulation, numerical modelling.

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Experimental evaluation of the fire behaviour of insulated fibre-reinforced-polymer-strengthened reinforced concrete columns

Fire Safety Journal ◽

10.1016/j.firesaf.2006.05.004 ◽

2006 ◽

Vol 41 (7) ◽

pp. 547-557 ◽

Cited By ~ 37

Author(s):

Venkatesh K.R. Kodur ◽

Luke A. Bisby ◽

Mark F. Green

Keyword(s):

Reinforced Concrete ◽

Experimental Evaluation ◽

Concrete Columns ◽

Fire Behaviour ◽

Reinforced Concrete Columns ◽

Reinforced Polymer ◽

Fibre Reinforced Polymer

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Behaviour of geopolymer concrete-filled pultruded GFRP short columns

Journal of Composite Materials ◽

10.1177/0021998319833447 ◽

2019 ◽

Vol 53 (18) ◽

pp. 2555-2567 ◽

Cited By ~ 2

Author(s):

Weena Lokuge ◽

Rajab Abousnina ◽

Nilupa Herath

Keyword(s):

Glass Fibre ◽

Geopolymer Concrete ◽

Load Carrying Capacity ◽

Reinforced Polymer ◽

Glass Fibre Reinforced Polymer ◽

Load Carrying ◽

Fibre Reinforced Polymer ◽

Glass Fibre Reinforced ◽

Polymer Tube ◽

Polymer Tubes

This research paper presents the results of an experimental investigation on the axial compressive behaviour of 24 geopolymer concrete-filled glass fibre-reinforced polymer tubes. The test variables considered are the compressive strength of geopolymer concrete (30 MPa and 35 MPa) and the shape of the cross section (square, circular and rectangular). All the glass fibre-reinforced polymer tubes had the same amount of fibres and similar fibre orientation together with the same aspect ratio. The failure of the square and rectangular columns initiated with the splitting of the corners and resulted in a lower load-carrying capacity compared to the circular columns whose failure was initiated by the crushing of glass fibre-reinforced polymer tube followed by the separation of glass fibre-reinforced polymer tube into strips. It can be concluded that axial load-carrying capacity of square and rectangular sections can be improved by a concrete filler with higher compressive strength. Adopted finite element analysis to simulate the behaviour of the columns is capable of predicting the stress–strain behaviour and the mode of failure.

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Comparison of the Flexural Performance and Behaviour of Fly-Ash-Based Geopolymer Concrete Beams Reinforced with CFRP and GFRP Bars

Advances in Materials Science and Engineering ◽

10.1155/2020/3495276 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15

Author(s):

Hemn Qader Ahmed ◽

Dilshad Kakasor Jaf ◽

Sinan Abdulkhaleq Yaseen

Keyword(s):

Crack Width ◽

Ultimate Load ◽

Load Capacity ◽

Reinforcement Ratio ◽

Geopolymer Concrete ◽

Ultimate Load Capacity ◽

Gfrp Bars ◽

Reinforced Polymer ◽

Fibre Reinforced Polymer ◽

Frp Bars

A construction system with high sustainability, high durability, and appropriate strength can be supplied by geopolymer concrete (GPC) reinforced with glass fibre-reinforced polymer (GFRP) bars and carbon fibre-reinforced polymer (CFRP) bars. Few studies deal with a combination of GPC and FRP bars, especially CFRP bars. The present investigation presents the flexural capacity and behaviour of fly-ash-based GPC beam reinforced with two different types of FRP bars: six reinforced geopolymer concrete (RGPC) beams consisting of three specimens reinforced with GFRP bars and the rest with CFRP bars. The beams were tested under four-point bending with a clear span of 2000 mm. The test parameters included the longitudinal-reinforcement ratio and the longitudinal-reinforcement type, including GFRP and CFRP. Ultimate load, first crack load, load-deflection behaviour, load-strain curve, crack width, and the modes of failure were studied. The experimental results were compared with the equations recommended by ACI 440.1R-15 and CSA S806-12 for flexural strength and midspan deflection of the beams. The results show that the reinforcement ratio had a significant effect on the ultimate load capacity and failure mode. The ultimate load capacity of CFRP-RGPC beams was higher than that of GFRP-RGPC, more crack formations were observed in the CFRP-RGPC beams than in the GFRP-RGPC beams, and the crack width in the GFRP-RGPC beams was more extensive than that in the CFRP-RGPC beams. Beams with lower reinforcement ratios experienced a fewer number of crack and a higher value of crack width, while numerous cracks and less value of crack width were observed in beams with higher reinforcement ratio. Beams with the lower reinforcement ratios were more affected by the type of FRP bars, and the deflection in GFRP-RGPC beams was higher than that in CFRP-RGPC beams for the same corresponding load level. ACI 440.1R-15 and CSA S806-12 underestimated the flexural strength and midspan deflection of RGPC beams; however, CSA S806-12 predicted more accurately.

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