Basalt Fiber Reinforced Polymer Research Articles

Experimental and analytical investigation of the behaviour of reinforced concrete beam under pure torsion

An experimental investigation and FE analysis are conducted on utilising basalt fibre-reinforced polymer (BFRP) fabric to increase the resistance of RC beams against torsion. A total of 4 no. of beams were cast with the same concrete batch mix M20. One beam was used as a control specimen, i.e. unstrengthened beam, and the other three beams were strengthened using BFRP laminates for different configurations, which includes one beam of Full U-Wrapping, one beam of strip wrapping of 150 mm width and 150 mm spacing between two strips and one beam of strip wrapping of 300 mm width and 150 mm spacing between two strips. Under purely torsion conditions, all of the beams were tested. All these beams have 150 mm × 250 mm c/s dimensions and 2100 mm in length. The beam contains bottom longitudinal reinforcement of 12 mm dia. and top longitudinal reinforcement of 10 mm dia. Stirrups used are of 8 mm diameter with 100 mm spacing; at support, it is 40 mm spacing for the length of 150 mm.The torsion test setup, loading frame and special end supports were fabricated for applying torsional load on beam specimens. The beams were subjected to pure torsional loading and twisting moment, and strains and twist angles were recorded. The experimental investigation results were validated using FEM-based ANSYS software. The model of the beams was created in SOLIDWORKS software and then imported into ANSYS for FE analysis. The simulations of beams were carried out in ANSYS Workbench. The effectiveness of U-wrapped beams was found to be better than the other strip-wrapping techniques.

Flexural Behavior of Concrete Box Girders Reinforced with Mixed Steel and Basalt Fiber-Reinforced Polymer Bars

Flexural Behavior of Concrete Box Girders Reinforced with Mixed Steel and Basalt Fiber-Reinforced Polymer Bars

Experimental Verification of Load-Bearing Capacity of FRP Bars under Combined Tensile and Shear Forces

In recent decades, the number of applications of fiber-reinforced polymer (FRP) reinforcement for concrete has significantly expanded. This fact is mainly due to the FRP reinforcement cost competitiveness, the increasing availability of design provisions, and due to the advantageous physical-mechanical and chemical properties of this composite material, which open up new possibilities for the design and implementation of extremely durable elements. Currently, the most commonly used types of reinforcement bars are those containing glass FRP (GFRP) or basalt FRP fibers, which is mainly the result of their favorable price and high resistance to aggressive environments. The use of composites in construction is wide-ranging: it is possible to apply FRP bars not only in the design and strengthening of concrete structures but also in the installation of shear dowels in concrete pavement, as rock bolts or as anchors for overhanging facade components. In the case of the design of load-bearing elements subjected to a combination of tensile and shear force, it is necessary to quantify their shear resistance and concisely describe the effect of the interaction of the tensile and shear force on the load-bearing capacity of the reinforcing element. This is a broadly addressed area as regards composite laminates and fabrics, but when it comes to FRP bars, there are very few available experimental results. For that reason, this research deals with the experimental testing and quantification of the influence of the interaction of normal and shear force. The behavior of GFRP bars from two different manufacturers, with three different diameters, different surface treatments, and mechanical characteristics, was experimentally verified. The findings are presented, a material failure curve is compiled, and the results are compared with those predicted according to the available relationship for composite laminates and von Mises theory.

Research of Moisture Sorption by Laminated Composite Materials

This article focuses on the moister sorption by laminated composites. Moisture sorption was carried out on layered polymer composite materials consisting of layers of basalt fabric and fiberglass based on epoxy-diane resin. It is shown that the process of moisture absorption for glass fiber-reinforced polymers is more intense and with a higher concentration of moisture in comparison with basalt fiber-reinforced polymer. Curves of the sorption processes of moisture absorption and water absorption are obtained. The diffusion coefficients for the corresponding processes are calculated. Alteration in the surface structure of polymer composite materials were recorded using surface topography and REM images before and after exposure in the climate of Yakutsk (Russia).

An Experimental and Numerical Analysis of Glued Laminated Beams Strengthened by Pre-Stressed Basalt Fibre-Reinforced Polymer Bars

Damage often develops in glued laminated timber members under high bending loads due to natural defects in the timber, which results in their low load-bearing capacity and stiffness. In order to improve the bending mechanical properties of glulam beams, a new type of longitudinal glulam reinforcement with pre-stressed basalt fibre-reinforced polymer composites (BFRP) was developed using the Near Surface Mounted (NSM) technique. The strengthening method consisted of two pre-stressed BFRP bars glued into the grooves at the bottom side of the beam; meanwhile, for the second strengthening alternative, the third BFRP bar was embedded into the groove at the top side of the beam. Therefore, an experimental study was carried out to verify this strengthening technique, in which fifteen full-size timber beams were tested with and without bonded BFRP bar reinforcement in three series. According to the results of this experimental study, it can be seen that the effective load-bearing capacity of the reinforced beams increased up to 36% and that the stiffness of the beams increased by 23% compared to the unreinforced beams. The tensile stresses in the wooden fibres were reduced by 11.32% and 25.42% on average for the beams reinforced with two and three BFRP bars, respectively. On the other hand, the compressive stresses were reduced by 16.53% and 32.10% compared to the unreinforced beams. The usual failure mode saw the cracking of the wood fibres at the defects, while for some specimens, there were also signs of cracks in the epoxy adhesive bond; however, the crack propagation was, overall, significantly reduced. The numerical calculations also show a good correlation with the experimental results. The difference in the results between the experimental and numerical analysis of the reinforced and unreinforced full-sized beams ranged between 3.63% and 11.45%.

Bond Performance of Anti-Corrosion Bar Embedded in Ceramsite Concrete in Freeze–Thaw Cycles and Corrosive Environments

At present, basalt fiber-reinforced polymer (BFRP) bars and epoxy-coated steel reinforcing bars (ECRs) are very promising in ocean engineering. In this study, the bond strength degradation characteristics of BFRP bars, ECR, and ordinary steel bars (OSBs) embedded in ceramsite concrete (CC) were compared in a single-corrosive environment (acid, salt, and alkaline salt, respectively) coupled with freeze–thaw (FT) cycles (0, 15, or 30); a total of 111 specimens were designed. In the three corrosive environments, the BFRP-bar-CC specimens and OSB-CC specimens all failed to pull out, while the ECR-CC specimens showed splitting failure. When corrosive and FT cycles acted together, the failure modes of BFRP-bar-CC specimens and ECR-CC specimens did not change. However, when the FT cycles increased from 15 to 30, the type of failure for the OSB-CC specimens changed from pullout failure to splitting failure. In addition, the bonding strength of the three kinds of bars decayed most rapidly in an acid environment. When 30 FT cycles were applied, the bond strength of ECR-CC specimens and OSB-CC specimens decreased most rapidly in the acid environment, by 9.12% and 18.62%, respectively. However, the bond strength of BFRP-bar-CC decreased most rapidly, by 17.2%, in an alkaline salt environment.

Mechanical properties of BFRP-reinforced glued laminated wood hollow round column under eccentric pressure

The FRP-wood column elements are lightweight and high performance, meeting the social demand for sustainable construction. In this study, a basalt fiber reinforced polymer (BFRP) reinforced glued laminated wood hollow round column structure is proposed. Small eccentricity compressive tests and numerical simulations were carried out on glued wood hollow columns strengthened with BFRP to study the effect of BFRP arrangement on the mechanical properties of glued wood hollow columns with constant material, size and eccentricity. All samples are compression side of the wood first yielded, and then some samples tensile side of the end of the wood fracture or the central section of the wood was pulled off, which belongs to the typical compression bending failure and conforms to the characteristics of small eccentric compression. The compressive load capacity of the wood column after BFRP pasting was increased by 3.4%∼30.54%, and the lateral flexural stiffness was increased by 1.44%∼23.86%. Meanwhile, pasting BFRP at the end and middle of the wood column can effectively restrain the compression deformation at the end and bending deformation at the middle, and obtain higher load capacity and lateral flexural stiffness. The numerical simulation results agree well with the experimental results and can effectively characterize the mechanical properties of BFRP-reinforced glued laminated wood hollow round column under eccentric loading conditions.

Effect of basalt minibars on the shear strength of BFRP-reinforced high-strength concrete beams

This research examined the effect of a novel type of stiff nonmetallic macro fibers, basalt macro fibers (BMF), on the shear strength and behavior of high-strength concrete (HSC) beams longitudinally reinforced with basalt fiber-reinforced polymer (BFRP) bars. Nine BFRP reinforced concrete beams (BFRP-RC) were cast and tested under two-point loads without BFRP stirrups. The volume fraction of BMF (Vf) and the BFRP longitudinal reinforcement ratio (ρf) were all evaluated; three volume fractions of BMF were used (0%; 0.75%; 1.5%), with three longitudinal reinforcement ratios (0.71%, 1.71%, and 2.54%). The results indicated that adding BMF to HSC-BFRP-RC beams enhanced the shear resistance. For concrete compressive strength of 90 MPa, the results show that adding BMF enhanced the shear resistance for all flexural reinforcement ratios; however, it is more effective in beams reinforced with a higher flexural reinforcement ratio. For beams reinforced with flexural reinforcement ratios of 0.71% and 2.54%, the shear resistance increased by 95% and 98%, respectively, due to adding 0.75% BMF, compared to 136% and 210% when 1.5% of BMF were added. And the post-cracking stiffness of all beams remarkably increased due to BMF addition. Furthermore, the effect of BMF on the mechanical properties of HSC was investigated. Finally, ACI 318–19, ACI 440.1R-15, and ACI 544.4R-18 were evaluated to predict the ultimate shear strength of HSC-BFRP-RC beams reinforced with BMF. The experimental results correspond well with ACI 544.4R-18 predictions of the shear strength of fiber-reinforced concrete (FRC) beams without shear reinforcement.

Mechanical properties of a novel UHPC reinforced with macro basalt fibers

Adding fibers in ultra-high performance concrete (UHPC) significantly enhances its mechanical properties. This study investigated the effects of the novel macro basalt fibers (MBF) content and geometric characteristics on flowability and mechanical properties of UHPC, the MBF which was a kind of minibar composited of basalt fiber reinforced polymers (BFRP). Two fiber shapes, including straight and twisted shape, and two aspect ratios with the volume fractions ranging from 0% to 3% were employed. The fiber distribution, interfacial bonding behavior between MBF and UHPC were tested and evaluated. The effects of MBF on the flowability, compressive strength, flexural strength and toughness of UHPC were revealed. The toughness, compressive strength, and flexural strength of UHPC increased with the increase of MBF content, but the flowability decreased. The relatively uniform fiber distribution was observed when the MBF content was lower than 3%. Compared with the straight MBF, the twisted MBF showed higher bonding behavior between fiber and UHPC. It resulted in that the twisted MBF performed more efficient in enhancing mechanical properties of UHPC than the straight MBF. The flexural post-cracking strength of UHPC with various MBF contents and geometric characteristics could be accurately predicted using the quadratic model and the modified model based on the Composited Theory because the values of R2 were more than 0.95.

Nano filler incorporated epoxy based natural hybrid fiber confinement of concrete systems: Effect of fiber layers and nano filler addition

The utilization of environment friendly materials in the construction industry is essential for sustainable development. For the purpose of strengthening and retrofitting concrete structures, fiber reinforced polymer (FRP) composites have been predominantly used. In the area of structural strengthening, as an alternative to synthetic fiber reinforced composites, the application of natural fiber reinforced composites is of immense interest. This study discusses the mechanical properties of externally strengthened concrete cylinders using a natural hybrid fiber system with two layers of sisal fiber sheets followed by 1 to 3 layers of basalt fiber sheets. In addition, the effect of multi walled carbon nanotubes (MWCNT) incorporation in the epoxy matrix from 0.5 to 1.5 wt%, on the various properties are analyzed. The inclusion of MWCNT in the epoxy matrix improved the overall performance of the FRP significantly. The results show that there is substantial improvement in mechanical properties up to 1 wt% MWCNT content in composites, beyond which it is reduced due to agglomeration of nanofiller. The MWCNT incorporated epoxy based five layered hybrid sisal basalt FRP confined specimens showed an improvement of 114% and 427% in peak strength and strain values under axial compressive strength tests. Moreover, the axial compressive behavior, stress–strain response, energy absorption and ductility characteristics of the confined column specimens were evaluated. The major focus of the study is to assess the influence of basalt FRP layers on the ultimate load carrying capacity and performance of hybrid sisal basalt FRP (HSBFRP) confined specimens. Statistical analysis of variance (ANOVA) was carried out and revealed that the number of FRP layers and addition of MWCNT in epoxy significantly affect the overall performance. The addition of basalt fiber layers in hybrid sisal basalt FRP systems is found to improve the load carrying capacity and energy absorption characteristics of confined specimens. Therefore, HSBFRP confinement can be used in areas where moderate strength and greater ductility is commanded.

Uplift Behaviour of External Fibre-Reinforced Polymer Wrapping on RC Piles in Dry and Submerged Sandy Soil

The sudden occurrence of an earthquake induces a liquefaction effect on foundation soil, which causes a substantial increase in the uplift pressure acting on piles and causes structural damage to superstructures. This forms the basis of the necessity of experimenting with the behaviour of piles subjected to uplift loads and predicting their load-carrying capacity or resistance. Fibre-reinforced polymer (FRP) wraps are widely used for strengthening and retrofitting piles subjected to damage. The current study is aimed at determining the uplift load-carrying capacity or resistance of piles wrapped with basalt fibre-reinforced polymer (BFRP) and glass fibre-reinforced polymer (GFRP) sheets by experiment. Preliminary tests were conducted to identify the influence of BFRP and GFRP wraps on the mechanical strength properties of concrete. The mechanical strength of the specimen with the double wrapping of basalt and glass fibres in the perpendicular direction outperformed all other specimens. Moreover, the piles were wrapped with laminates and experimented on for their uplift capacity in dry and submerged conditions. The results indicate a considerable improvement in the uplift resistance of the piles compared with the unconfined piles. The BFRP and GFRP wraps improved the uplift resistance of the piles by 35.56% and 15.56%, respectively, higher than the unconfined pile for dry conditions. The angle of the interfacial friction in dry and submerged states was observed to be the maximum for the perpendicular direction for both of the FRP wraps, and the failure modes were compared. The simulated model showed a significant correctness for determining the uplift resistance of FRP-wrapped piles in dry and submerged states. The degree of agreement in the dry condition for the experimental results and finite element method was more than 94% for all fibre wraps.

Bond behavior of recycled tyre steel fiber reinforced concrete and basalt fiber-reinforced polymer bars under static and fatigue loading conditions

Nowadays, there is a growing demand for the development of structures and construction materials from recycled or reused and renewable resources, in line with circular economy principles and the goal of sustainable development. The present study explores promising solutions for increasing the sustainability of concrete structures, through the application of basalt fibers reinforced polymer (BFRP) rebars, whose raw materials show an unlimited availability on earth, as well as recycled steel fibers from waste tyres (RTSF), for RTSF reinforced concrete structures with BFRP reinforcements. Three different types of self-compacting concretes with 1.1% fiber volume fractions of industrial and/or recycled steel fibers were developed, where 50% and 100% of the industrial steel fibers (ISF) weight was replaced by RTSF. Five different groups of pull-out specimens, with total number of 26 specimens, were fabricated to evaluate bond performance of BFRP rebar embedded in RTSF reinforced concrete. The understanding of the bond behaviour is critical to the effective design of reinforced concrete structures under both static and dynamic loadings. The influence of the type of reinforcement, dosage of the adopted RTSF, type of loading, and concrete flow direction on bond stress versus slip behavior, maximum bond stress, and failure mode are analysed and discussed. One of the main contributions of this research regards the understanding of the effect of RTSF orientation on bond performance obtained when BFRP rebars are pulled out from RTSF reinforced concrete. Compared to ISF, using RTSF for reinforcing concrete can increase the bond strength between BFRP rebars and fiber reinforced concrete up to 6.3% under static and 9.7% under fatigue loading regime. As the future research in this area, it is recommended to evaluate the long-term bond durability of BFRP reinforced FRC embedded in seawater, the environmental and economic feasibility of using BFRP and TRSF for reinforcing concrete structures, and fiber orientation and dispersion using image analysis and 3D visualization.

Experimental study on the mechanical properties and failure modes of BFRP bar anchor systems under static tension loading

Basalt fiber-reinforced polymer bars are lightweight composite materials with high strength, low density, and excellent corrosion resistance. The anchor system made from basalt fiber-reinforced polymer bars is worthy of being developed and expected to be used in rock anchoring projects. In this work, four different basalt fiber-reinforced polymer anchor systems were designed, the influences of different design parameters on the ultimate bearing capacity of the anchor system were investigated through tension tests, and the failure modes of different anchor systems were elucidated. The test results indicated that failure modes, such as the transverse fracture of these bars and debonding of the bonding medium, were widely present in the wedge-modified anchor system and the steel-pipe-protected anchor system. These two anchor systems performed poorly with the wedge anchorage, whereas the basalt fiber-reinforced polymer bars protected by seamless steel pipes burst under the tension imposed by a universal testing machine. The threaded steel-pipe-bonded anchor system and the steel strand–basalt fiber-reinforced polymer bar composite anchor system had maximum anchorage efficiency coefficients of 97.7% and 98.5%, respectively. The bars in the corresponding test groups all exhibited burst failure, indicating that these two anchoring structures achieved effective anchorage of the basalt fiber-reinforced polymer bars.

Cyclic load tests and finite element modeling of self-centering hollow-core FRP-concrete-steel bridge columns

This paper presents experimental and numerical investigations of the seismic performance of a novel self-centering (SC) hollow-core (HC) fiber-reinforced polymer (FRP)-concrete-steel (SC-HC-FCS) bridge column. This new structure is fabricated by mounting external energy dissipators (ED) and applying unbonded post-tensioned (PT) basalt FRP (BFRP) tendon to the conventional HC-FCS column that consists of an outer FRP tube and an inner steel tube, with the space between filled with concrete. The SC-HC-FCS column combines the advantages of accelerated bridge construction and self-centering. The effects of the initial prestress force values and the configuration of the energy-dissipated aluminum bar on the column performance are studied. Based on the experimental and numerical results, it is found that the proposed SC-HC-FCS column shows adequate self-centering and energy dissipation capacities. However, it is required to properly select the configuration and material properties of the aluminum bar as energy dissipators to further refine the seismic resistance of the SC-HC-FCS column.

Pullout behaviors of basalt fiber-reinforced polymer bars with mechanical anchorages for concrete structures exposed to seawater

This study presents an investigation of the pullout behaviors of basalt fiber-reinforced polymer (BFRP) bars with mechanical anchorages in concrete exposed to seawater. A total of forty-eight pullout specimens were prepared. Three types of mechanical anchorages that can be flexibly assembled on FRP bars, that is, additional straight bar, additional hook, and composite head, were adopted. The experimental variables comprised the anchorage type, conditioning temperature, and conditioning duration. The maximum pullout load (Pmax) and corresponding slip (smax), and the plateau length at the peak (lp) and slope of the descending branch (kd) of the load-slip curves, were evaluated and discussed. The results show that mechanical anchorages contribute to significant increases in the lp and decreases in the kd. Furthermore, the composite head achieves 32 % and 10 % increases in Pmax and lp respectively, and 20 % and 36 % decreases in smax and kd respectively, compared with the other two types of anchorages. After conditioning in seawater, the specimens with composite heads exhibit no significant degradation in their pullout behaviors, which indicates the effectiveness of the composite head in the protection against corrosive media. These results demonstrate the application prospects of a composite-head mechanical anchorage for FRP reinforcement in concrete structures constructed in the marine environment.

Effect of temperature on the flexural and ILSS behaviour of symmetric and asymmetric basalt fibre-reinforced polymer composites

Effect of temperature on the flexural and ILSS behaviour of symmetric and asymmetric basalt fibre-reinforced polymer composites

Improvement in alkali‐resistance of basalt fiber‐reinforced polymer by Ti3C2TX (MXene) modified matrix

AbstractFiber‐reinforced polymer (FRP) is a kind of potential construction material due to its low density and strong mechanical properties, but its weak alkali stability impedes its widespread use. MXene nanosheets' two‐dimensional (2D) property makes them an attractive contender as a nanofiller for polymer‐based composites. Here, a basalt fiber‐reinforced polymer (BFRP) laminate with a matrix modified with MXene nanosheets was made using a vacuum‐assisted resin‐transfer molding (VaRTM) process. The flexural strength (530.1 MPa) and flexural modulus (26.7 GPa) of the M0.5/BFRP composite were superior to those of the BFRP laminate, increasing by 39.4% and 4.6%, respectively. According to DMA examination, the MXene/BFRP composite exhibited increased crosslinking density, which could improve stability as well as aid in energy dissipation. As anticipated, the BFRP composites enhanced with MXene nanosheets demonstrated exceptional long‐term stability in a hostile alkali environment. After being submerged in alkali solution at 40°C for 60 days, the M0.5/BFRP's flexural strength reached 398.0 MPa, exceeding that of pristine BFRP that had not been submerged in alkali solution. This study gives an insight into the effect of MXene Ti3C2TX nanosheets modified resin on the durability of BFRP in strong alkali environment.

Experimental study on pullout behaviour of basalt fiber-reinforced polymers minibar embedded in ultra-high performance seawater sea-sand concrete

Pullout tests were conducted on 150 specimens to characterize the bond behaviours of eco-friendly basalt fiber-reinforced polymer minibars (MB) embedded in ultra-high performance seawater sea-sand concrete (UHP-SSC). The experimental variables comprised surface textures of MB (straight and twisted), constituent contents of crushed seashell (SH), and coarse aggregate (CA) in UHP-SSC. The microstructures and surface morphologies of the UHP-SSC matrix and MB were characterized by low-field nuclear magnetic resonance (LF-NMR) and scanning electron microscopy (SEM). A constitutive model for the pullout load-slip relationships was proposed. Experimental results showed that the increments in the bond strength and energy absorption capability provided by twisted MB were more than twice those provided by straight MB, resulting from the additional mechanical anchorage. The acceptable content of SH in sea sand is less than 5% since it could enhance bond strength by 6%, while significant contents show opposite effects. Incorporating CA decreased the interfacial bond behaviours between MB and UHP-SSC, especially with a high volume fraction exceeding 10%. The microscopic observations and pore structures consisted of the evolution of bond behaviours and clarified the corresponding mechanism. The proposed constitutive model considering SH and CA content fits well with the experimental data with relevant regression coefficients over 0.89.

Effect of corroded reinforcement on capacity of square reinforced concrete columns confined with FRP sheets under eccentric loads

Steel corrosion is one of the primary causes which significantly degrade the load-carrying capacity and FRP (fibre reinforced polymer) strengthening efficiency of FRP-strengthened reinforced concrete columns under eccentric loading. However, this issue has not been studied comprehensively and systematically in the literature. Particularly, there has been no study on the strengthening efficiency of basalt FRP (BFRP) which is becoming popular due to its excellent performance and affordable price. This study experimentally investigates the effect of corrosion level of reinforcement by mass (0%, 15% and 30%), relative eccentricity (e/h = 0.125 and 0.375), type of FRP (CFRP and BFRP) and FRP thickness (1 or 3 layers) on the load-carrying capacity and deformation of corroded-reinforcement reinforced concrete (RC) columns. The experimental results showed that steel corrosion reduced the load-carrying capacity of the unstrengthened RC columns up to 23% and this degradation increased with the corrosion level. Both CFRP and BFRP have proven excellent strengthening efficiency since the capacity of the FRP-strengthened corroded-reinforcement RC columns increased up to 47%. Particularly, the strengthening efficiency of BFRP sheets was slightly lower than that of CFRP sheets (<7%). On the other hand, the increase of the relative eccentricity from e/h = 0.125 to e/h = 0.375 reduced the strengthening efficiency of FRP. In addition, a semi-empirical model was proposed to predict the capacity of corroded-reinforcement RC columns strengthened with FRP under eccentric loading. The predictions match well with the experimental results with a small coefficient of variation.

Axial compressive behavior of basalt and carbon FRP-confined coal gangue concrete

Coal gangue concrete (CGC), in which fine and coarse aggregates are completely replaced by coal gangue aggregates, has been limited to non-structural applications owing to its brittle structure, lower strength and stiffness. Nevertheless, the disadvantages of CGC can be minimized by external confinement of fiber-reinforced polymer (FRP) jacket. A total of 39 cylindrical specimens were studied under a monotonic axial compression test to understand the compressive behavior of FRP-confined CGC, considering the CGC strength, FRP layer number, basalt FRP (BFRP) and carbon FRP (CFRP) type as variables. The failure modes, stress–strain relationship, and dilation properties were analyzed in detail. The results indicate that the strength of the BFRP/CFRP-confined CGC was improved by 16.9%–145.8%, and the axial ultimate strain was 4.787–8.812 times that of the plain CGC. The stress–strain curve of the BFRP/CFRP-confined specimen exhibited a bilinear response, where the second portion showed a descending shape under weak confinement and an ascending branch under strong confinement, mainly depending on the FRP confining ratio. Additionally, the axial strain of the confined CGC is larger than that of the confined normal concrete when given the same lateral strain. Most importantly, the modified discriminative models and ultimate strength and strain models for BFRP/CFRP-confined CGC were proposed, providing a theoretical basis for its application in mines.