Basalt Fiber Reinforced Polymer Research Articles

Evaluation of BFRP strengthening and repairing effects on concrete beams using DIC and YOLO-v5 object detection algorithm

In this study the effectiveness of using Basalt Fiber Reinforced Polymer (BFRP) for strengthening and repairing concrete beams after pre-damage was investigated. Four-point bending tests were conducted on concrete beams, and their strain nephograms were analyzed using 3D-DIC (Digital Image Correlation) to assess the BFRP reinforcement and repair effects on concrete. A damage indicator model based on stress-displacement curves was proposed to quantify concrete damage and evaluate the BFRP strengthening effect. Additionally, the YOLO-v5 object detection algorithm was employed to detect surface damage on concrete specimens, and its results were cross-verified with the damage indicator. The study reveals that BFRP reinforcement primarily affects the concrete beams beyond the elastic limit, enhancing their load-bearing capacity by 37.91% and improving ductility. The proposed damage indicator proves successful in quantifying damage in BFRP-reinforced concrete beams, distinguishing the transition points between elastic, cracking, and failure stages. The YOLO-v5 algorithm accurately detects damage in strain nephograms, providing sensitive and timely identification of concrete damage. Results proves that the offset ratio between the damage identification results of YOLO-v5 and the experimental stress-displacement curve data is between − 3.03% and 8.66%. The proposed damage indicator and YOLO-v5 detection offer valuable tools for evaluating damage and monitoring the health of concrete structures in engineering applications.

Deterioration of bond performance between BFRP bars and coral aggregate concrete incorporating slag-based geopolymers under seawater corrosion environments

The utilization of durable geopolymers instead of ordinary Portland cement (OPC) for developing geopolymer-based seawater coral aggregated concrete (GPCAC) in coastal constructions contributed to the improved marine resource utilization and the reduced CO2 emissions and construction costs. Thus, this study investigated the durability of GPCAC and its bond performance with basalt fiber-reinforced polymer (BFRP) bars under seawater drying-wetting cycles, and cement-based CAC was also selected as a comparison. The bond characteristics and degradation mechanisms of slag-based GPCAC and cement-based CAC specimens were compared and analyzed under different seawater exposure condition. Experimental results revealed that both GPCAC and CAC specimens demonstrated various degrees of degradation in bond strength, whereas their initial bond stiffness exhibited a slight increase owing to the hygroscopic expansion of the superficial epoxy resin of BFRP bars, after being exposed to seawater environmental attacks. This degraded bond strength was primarily attributed to the existence of corrosive ions (i.e., SO42-, Mg2+, and Cl-) in seawater and free OH- in concrete capillary pores. These compounds chemically reacted with the slurry hydration products and the resin matrix, which resulted in the decreasing of concrete strength, the hydrolysis of the resin matrix, the deterioration of fibers, and fiber-resin interface debonding. Compared with CAC specimens, GPCAC specimens achieved better resistance to seawater attacks owing to the more dense and stable reaction products formed by geopolymers compared to OPC. After being subjected to 60 °C seawater attacks for 12 months, approximately 4.9% and 12.0% reductions in the bond strength were reported for GPCAC and CAC specimens, respectively. Finally, the residual bond strength of both GPCAC and CAC specimens was predicted after being served in seawater erosion conditions for 50 years.

Effect of Polyurethane Treatment on the Interfacial and Mechanical Properties of Basalt Fiber-Reinforced Polymer Composite

Effect of Polyurethane Treatment on the Interfacial and Mechanical Properties of Basalt Fiber-Reinforced Polymer Composite

Compressive behavior of BFRP-confined ceramsite concrete: An experimental study and stress–strain model

Abstract The novel structure of a basalt fiber reinforced polymer (BFRP)-confined ceramsite concrete column (BFCCC) reinforced with bamboo strips (BSs) was investigated. The characteristics of light weight, BSs and FRP reinforcement were reflected in the structure. Thirty-six BFCCCs and 18 unconfined ceramsite concrete columns were fabricated and subjected to axial compression tests, and the stress–strain curves were obtained. The research parameters included the number of BFRP layers and the volume content of BSs. Both types of specimens, with and without BFRP confinement, underwent brittle failure after reaching the ultimate bearing capacity. The increase in the number of BFRP layers had a positive effect on the bearing capacity and deformation capacity of the specimens. With the increase in the number of BFRP layers, the compressive strengths of BFCCCs were improved by 1.17–1.44 times, and the deformations were improved by 6.30–12.92 times, compared to the unconfined concrete. The addition of BSs could improve the ductility of the specimen, while the effect on the bearing capacity had an optimal value of 2.0%. The stress–strain curves of the BFCCCs showed obvious softening behavior after the peak point. Models were proposed to predict the axial stress–strain curves of BFCCCs reinforced with BSs.

Nonlinear Coupled Vibration Behavior of BFRP Cables on Long-Span Cable-Stayed Bridges under Parametric Excitation

Based on the cable-stayed beam model, this paper studies the nonlinear coupled vibration behavior of basalt fiber-reinforced polymer (BFRP) cables on long-span cable-stayed bridges under parametric excitation. Considering the sag, damping of BFRP cables, and the coupled interactions between stayed cables and the main girder, the nonlinear coupling vibration model of the BFRP cable–beam composite structure has been established. Taking the longest cable of Sutong Bridge as a case study, the nonlinear coupled vibration behavior of BFRP cables under parametric excitation has been numerically analyzed using the finite difference method. The analysis results indicate that (1) under parametric excitation, the large amplitude nonlinear vibration of the BFRP cable will be induced with an evident “beat” phenomenon. (2) Under the same parametric excitation, the nonlinear coupling vibration response and the beta frequency of the BFRP cable were both smaller than that of the traditional steel cable. (3) The nonlinear coupling vibration response of the BFRP cable increased with an increment in excitation amplitude and a decrement in cable force. With the increase in the excitation frequency, weight per unit length, and axial stiffness, the nonlinear vibration response of the BFRP cable increased first and then decreased. Meanwhile, the damping ratio of the BFRP cable had no significant influence on the nonlinear coupling vibration.

Tests and modeling of hybrid fiber-reinforced geopolymer concrete elements having BFRP helix: An application for sustainable built environment

Due to the high quantity of carbon emissions from the cement industry, sustainable development for the built environment applications is required by utilizing geopolymers in concrete construction. Considering this problem, the structural efficiency of hybrid fiber-reinforced geopolymer concrete (HFGC) compressive elements made of basalt fiber-reinforced polymer (BFRP) bars is not well understood through experiments or numerical modeling in the literature. By conducting experiments and using finite element analysis (FEA) modeling, the primary goal of current research is to examine and compare the structural performance of BFRP-reinforced HFGC compressive elements (GHC) and steel-reinforced HFGC compressive elements (SHC), both of which are subjected to either concentric and or eccentric loading. The HFGC was created using a combination of steel and polypropylene fibers. Twelve circular compressive elements with a cross-sectional dimension of 300 mm and a height of 1200 mm were created i.e., six GHC and six SHC compressive elements. A parametric study was carried out using the proposed FEA model. The findings of the current research showed that the axial strength of GHC compressive elements was on average 91.8 % that of SHC compressive elements. Both types of elements depicted similar amounts of reduction in the axial strength when subjected to eccentric loads, for instance, 38.5 % and 144.2 % reductions were observed for GHC elements having helix spacing of 38 mm compared with the concentrically loaded counterparts. The recommended analytical relationship based on the database also performed well. The comparative study, which considers the axial involvement of main BFRP bars and the confinement effect of transverse BFRP helix, firmly supports the validity and applicability of the newly developed analytical and FEA models for capturing the axial strength of GHC compressive elements.

Assessment of damage evolution of concrete beams strengthened with BFRP sheets with acoustic emission and unsupervised machine learning

Basalt fiber reinforced polymer (BFRP) is an emerging material that can be used to strengthen or repair concrete structures. This paper experimentally investigates the flexural failure process of concrete beams strengthened by BFRP sheets under four-point loading conditions using acoustic emission (AE)-based nondestructive evaluation and unsupervised machine learning techniques. Both damaged beams and repaired beams were tested and compared with intact beams regarding their mechanical performance and AE signature. Test results showed that BFRP sheets enhanced the load-bearing capacity of the beams significantly, and AE signals were sensitive to the initiation and development of damages. The damage process and mechanisms of different beams have been investigated by analyzing AE signals regarding various AE parameters, and particularly, the failure process and damage mechanisms were investigated via b-value and k-means clustering analyses. This research provides theoretical guidance for evaluating the reinforcing effect of BFRP sheets for concrete beams based on AE techniques.

Dynamic characteristics of basalt fibre-reinforced polymer cement mortar bolts and its applicability for bolt defect detection

Basalt fiber reinforced polymer (BFRP) bolt has the advantages of high tensile strength, low quality and corrosion resistance. This kind of bolt has a potential application prospect in tunnel and underground engineering support. However, there is no effective method for non-destructive testing of anchoring quality of BFRP cement mortar, which restricts the application of this kind of anchor. Based on the propagation principle of stress waves in solids, the feasibility of the impact elastic wave method in detecting the length and compactness of bolts is theoretically demonstrated. Then, numerical simulation and test methods were used to study the propagation characteristics of stress waves in bolts under impact load and its application in the anchorage quality inspection of BFRP bolts. The results show that the elastic wave method can be used to detect the length of BFRP bolts and the detection accuracy meets the engineering requirements. In terms of anchoring compactness of cement mortar, this method can identify the location of defects, but the detection accuracy needs to be further improved. The research results presented in this paper can promote the application of BFRP bolts in tunnel and underground engineering support.

Effects of pre-cracked width and seawater erosion on the cracking behavior of SFRC beams with BFRP bars subjected to cyclic loading

This study aims to explore the effects of various pre-cracked widths, seawater erosion and BFRP reinforcement ratios on the cracking behavior of steel fiber reinforced concrete (SFRC) beams with Basalt Fiber Reinforced Polymer (BFRP) bars subjected to cyclic loading. Pre-cracked beams were made by applying loads to obtain a predetermined crack width, such as 0.02 mm, 0.2 mm, and 0.4 mm crack widths. Eleven beams were poured and tested by a four-point bending load under cyclic loading. The crack pattern and load-crack width curves of beams were drawn and analyzed. The effects of pre-cracked width, seawater erosion, and BFRP reinforcement ratio on crack behaviors of beams were investigated and discussed. The results showed that the tensile strength of BFRP bars degenerated after seawater corrosion, and its degradation rates increased with the increase of diameter. The failure mode of beams after seawater erosion may transform from concrete crushing failure to BFRP tensile failure; The maximum crack width of all beams under service load was less than 0.5 mm. Increasing the BFRP reinforcement ratio can significantly improve the crack resistance of beams, but pre-cracked width and seawater erosion had adverse effects on the crack behavior. Existing codes overestimated the crack width of SFRC beams reinforced with BFRP bars. Finally, a new calculation model of crack width of SFRC beams with BFRP bars after seawater corrosion was proposed, and its results were closer to the experimental results.

Flexural behavior of the corroded RC beams strengthened with BFRP grid-reinforced ECC

In marine environment, the reinforced concrete (RC) used in offshore structures is subjected to significant erosion by chloride ions, resulting in severe degradation of its mechanical performance. Therefore, it is essential to employ appropriate strengthening techniques to enhance the mechanical properties of such corroded components. To assess the effectiveness of these strengthening techniques, this study investigated the flexural behavior of corroded RC beams strengthened with Basalt Fiber Reinforced Polymer (BFRP) grid-reinforced Engineered Cementitious Composite (ECC). A series of numerical models were developed and their accuracy was verified through experimental results. Subsequently, the contributions of various components to flexural capacity, stress distribution, and the neutral axis position at different stages were investigated through numerical analysis. Additionally, the impact of key parameters on the flexural capacity of the hybrid beams was discussed. Finally, a theoretical model was proposed to predict the moment-displacement curves of the hybrid beams. The results showed that, at the point of hybrid beam failure, the stress within the BFRP grid reached 50%–70% of its maximum tensile stress. As the cross-sectional area of the BFRP grid increased, it effectively delayed the failure caused by tensile stress in the hybrid beam. The theoretical model successfully predicted the moments of the hybrid beams at three feature points.

Improved Mechanical Properties of Basalt and Glass Fibre Reinforced Polymer Composite by Incorporating Nano Silica

Granite waste that increasingly accumulates yearly is significant with granite industry growth. This research aims to use nano silica extracted from granite dust to identify the effect of nano silica on the mechanical properties of Basalt and Glass Fibre Reinforced Polymer Composite. The approach encompassed three distinct weight percentages of nano silica, specifically 1 wt%, 3 wt%, and 5 wt%, seamlessly blended into a polyester resin matrix. The evaluation of composite mechanical attributes was conducted through compression and Izod impact tests by following ASTM D3410 and ASTM D256. Remarkably, the pinnacle of this enhancement materialises at the 1 wt% threshold,signifying the impact strength and compression strength values. Beyond this point, a decline was observed, underscoring the critical importance of judicious weight percentage selection. This novel composite configuration holds promising implications, particularly for components within container trucks, where the fusion of exceptional impact and compression strength is paramount.

Bond Behavior of Recycled Tire Steel-Fiber-Reinforced Concrete and Basalt-Fiber-Reinforced Polymer Rebar after Prolonged Seawater Exposure

The integration of basalt-fiber-reinforced polymer (BFRP) rebars into concrete design standards still remains unrealized due to limited knowledge on the performance of the rebars in concrete, particularly in terms of bond durability in harsh conditions. In this work, we investigated the bond durability characteristics of BFRP rebars in fiber-reinforced self-compacting concrete (FRSCC) structures. To this aim, a number of 24 FRSCC pullout specimens reinforced with either BFRP rebar or glass-fiber-reinforced polymer, GFRP, rebar, which is a commonly used type of FRP, were fabricated. Half of these specimens were submerged in simulated seawater for a two-year span, while the other 12 similar specimens were maintained in standard laboratory conditions for comparative purposes. Subsequently, all 24 specimens underwent monotonic and fatigue pull-out tests. The exploration in this study focused on investigating the influence of the environmental condition, reinforcement type, and loading type on the bond stress versus slip relationship, maximum bond stress, and failure mode of the specimens. Based on the results obtained and by adopting the durability approach of industry standards for prediction of the bond retention of FRP-reinforced concrete, the bond strength retention between BFRP/GFRP and FRSCC after 50 years of exposure to seawater was estimated. The outcomes of the study are expected to enhance engineers’ confidence in the use of FRP, especially BFRP, for constructing durable and sustainable reinforced concrete structures in aggressive environments.

Compressive response of GFRP and BFRP bars at different temperatures and quasi-static rates

The adoption of fiber-reinforced polymer (FRP) bars in concrete structures has increased due to their superior mechanical properties and durability. However, the compressive response of FRP bars at high temperatures remains unclear. This article presents an experimental study on the behavior of glass FRP (GFRP) and basalt FRP (BFRP) bars subjected to compressive loads at different elevated temperatures and deformation rates. The study considers four different temperature conditions: ambient temperature (25 °C), 50 °C, 100 °C, and 150 °C, and two different deformation rates: 0.5 mm/min and 1000 mm/min. Digital Image Correlation (DIC) was used to accurately measure strains at high temperatures by generating a suitable speckle pattern over the specimen surface for full-field deformation measurements. The study results revealed that the modulus of elasticity and compressive strength of both GFRP and BFRP bars degraded as the temperature increased from 25 °C to 150 °C. The compressive strength reduction was higher at 150 °C compared to 100 °C, and the reduction was more significant for BFRP bars than GFRP bars. The compressive strength of GFRP bars was comparable under both strain rates for all temperature conditions. However, the elastic modulus of the bars showed a slight variation between the different load rates, especially at an elevated temperature of 150 °C. For the BFRP bars, the study found that different strain rates at ambient temperature resulted in significant deviation in the compressive strength and modulus of elasticity results. At higher temperatures, the reduction in mechanical properties was more pronounced. In summary, the study provides valuable insights into the behavior of GFRP and BFRP bars under compressive loads at elevated temperatures, which is useful for designing and assessing the performance of FRP-reinforced structures under fire conditions.

Behavior of Shear-Critical Recycled Aggregate Concrete Beams Containing BFRP Reinforcement

The shear performance of recycled aggregates beams reinforced with basalt fiber-reinforced polymer (BFRP) bars is evaluated and compared with that of similar beams made with natural aggregates (NA). Six beams with a shear span-to-effective depth ratio (a/d) of 3.0 were tested to failure. Test variables consisted of the recycled concrete aggregate (RCA) replacement percentage (60 and 100%) and the presence of BFRP stirrups in the shear span. Experimental results showed that a RCA replacement of 60% marginally reduced (5%) the shear capacity. However, the reduction in the shear capacity was more pronounced (17%) for the specimen made with 100% RCA. The contribution of BFRP stirrups to the shear capacity decreased with an increase in the RCA replacement percentage. The width of the major shear crack at a given value of load was higher for the beams with RCA. The deflection values at the ultimate load were greater for beams made with RCA. A codified analytical approach as well as a model published in the literature were employed to predict the shear capacity of the tested beams. Predictions of the codified analytical approach were very conservative. The analytical model published in the literature provided a more reasonable prediction for the shear capacity of the tested beams than that of the codified analytical approach.

Two-Way Slab Punching Shear Resistance: Experimental Insights into Basalt-FRP Bar as Flexural Reinforcement

This study seeks to experimentally evaluate the punching shear performance of two-way concrete slabs reinforced with conventional steel and basalt fiber-reinforced polymer (basalt-FRP) bars subjected to punching loading condition. Basalt-FRP bars offer high tensile strength and corrosion resistance but are understudied in two-way concrete slabs concerning punching shear. This study aims to fill this gap, with key implications for future structural design considerations. To achieve the objectives of the study, six large-scale square slabs were fabricated and subjected to a concentric load until failure. The parameters of the experiment included are the type of reinforcement used (either basalt-FRP or steel), the percentage of basalt-FRP used (ranging from 0.88% to 1.77%), the size of the basalt-FRP bars used (either 16 or 12 mm), and the concrete’s compressive strength (25, 30, and 35 MPa). The findings from the tests showed that incorporating basalt-FRP bars with one-quarter equivalent axial stiffness (ρ(Ef/Es)) to that of steel significantly enhanced the punching shear resistance of flat slabs, achieving approximately 65% of the capacity observed in steel-reinforced control sample. Moreover, increasing the amount of basalt-FRP bar reinforcement to half of the equivalent axial stiffness of steel had a substantial effect in improving shear strength, reaching approximately 89% of the capacity observed in the steel-reinforced specimen and concurrently reducing deflection during the failure. Additionally, the reinforcement type and concrete compressive strength played a crucial role in determining the ultimate load, failure modes, and crack propagation patterns. The study reveals discrepancies between experimental results and existing models for punching shear in FRP-reinforced slabs. Certain prevalent models prove to be conservative in their estimates, while others offer more accurate predictions, indicating the need for comprehensive model refinement. The investigation found that one model, encompassing the majority of variables affecting punching shear, exhibited the highest level of precision, with a slight adjustment recommended to enhance its accuracy further. This study suggests a sustainable, more durable way to reinforce concrete in bridges and high-rise buildings, potentially improving construction efficiency, enhanced service life, and potential updates to building codes.

Stability analysis of pultruded basalt fiber-reinforced polymer (BFRP) tube under axial compression

This study analyzed mechanical properties and stability of pultruded basalt fiber-reinforced polymer (BFRP) tubes under compressive axial loading for large-span space and truss structures applications. This study assessed the compressive strength of BFRP tubes with three different cross-sectional shapes and investigated the failure modes under compression with slenderness ratios ranging from 20 to 150. The results demonstrated that short BFRP tubes can achieve a compressive strength of up to 122.36 MPa with a compressive elastic modulus of 40.39 GPa. Three types of compressive failure modes were observed in the BFRP tubes, including local material, critical, and overall buckling failures. Furthermore, based on the analysis of experiment results, two design-oriented three-stage theoretical models were proposed for BFRP tubes with three different cross-sectional shapes. The proposed models were able to predict both the stress–strain and load-lateral deflection curves by taking into account the post-peak softening behavior of the stress–strain curve. In addition, a stability equation was also derived for predicting the compressive strength of slender BFRP tubes and was validated by experiments. The predictions derived from proposed models were consistent with experiment results.

Effects of surface characteristics and alkalinity on the deterioration of BFRP bars and BFRP-SSC interface in seawater environment

This study investigated the surface characteristics and concrete alkalinity on the deterioration of basalt fiber reinforced polymer (BFRP) bars and the interface between BFRP bars and seawater sea-sand concrete (SSC) in a seawater environment. The degradation of BFRP bars with three surface characteristics (sand coating, helically-wound, and helically-wrapped) embedded in two alkalinities of SSCs and BFRP-SSC interface were studied by shear, tensile, and pull-out tests, respectively. Additionally, the microstructure of the BFRP and BFRP-SSC interface was characterized by Fourier transforms infrared spectroscopy (FTIR), X-ray computed tomography (X-CT), and scanning electron microscope (SEM). The experimental results showed that sand-coated BFRP bars exhibit the best durability performance among the three types of BFRP bars due to forming a protective layer of sand and the helically-wound BFRP bars degrade from the groove (rich fiber and less resin protection zone). The degradation of BFRP bars in low alkalinity (LA) SSC is significantly mitigated owing to the reduced alkalinity. Furthermore, the hindering effect of the sand layer also enhances the bond durability between bars and SSCs compared with the other two types of BFRP bars. The bond strength between BFRP bars and LA-SSC is slightly reduced after 180 days of seawater immersion, while that in ordinary (O) SSC decreases significantly. The pull-out failure of sand-coated BFRP bars in LA-SSC is wearing out of the sand layer and surface resin after environmental conditions, while that of helically-wound BFRP bars in LA-SSC are peeling off ribs. The research outcomes can serve as solid base for employing BFRP bars in the marine environment.

Durability of GFRP and BFRP reinforcing bars in simulated seawater sea sand calcium sulfoaluminate cement concrete pore solution

Thanks to the much smaller carbon footprint of calcium sulfoaluminate cement (SAC) concrete and the corrosion resistance of fiber reinforced polymer (FRP) reinforcement, FRP-reinforced SAC concrete can possibly replace conventional reinforced concrete in some cases. In this study, for the first time, the durability of glass FRP (GFRP) and basalt FRP (BFRP) bars, made with epoxy resin, is investigated in simulated pore solutions of concretes made with (a) SAC and fresh water, (b) SAC and seawater and sea sand. The bars were immersed in each solution and kept at constant temperature of 30 °C, 45 °C and 60 °C for up to 180 days. Bar samples were tested for their retained tensile strength and physiochemical degradation after 30, 60, 90, and 180 days of immersion. Scanning electron microscopy (SEM), X-ray dispersive spectroscopy (EDS), and Fourier transform infrared (FTIR) spectroscopy were used to identify the underlying damage mechanisms. Results show that solution (b) is less harmful to BFRP than solution (a), while the opposite is true in the case of GFRP. Both solutions caused the dissolution of the epoxy resin and the leaching of the Fe in the basalt fiber. Overall, GFRP exhibited higher durability than BFRP. Based on image analysis, the deteriorated zone within the bar cross-section is not a uniform ring, but its area correlates with the loss of tensile strength. Inspired by the Avrami-Erofe'ev Equation and the Eyring's Transition State Theory, a novel time-temperature-dependent FRP bar degradation model is proposed. The proposed model shows close agreement between the predicted and measured tensile strengths.

Constructing quasi-vertical fiber bridging behaviors of aramid pulp at interlayer of laminated basalt fiber reinforced polymer composites to improve flexural performances

Basalt Fiber Reinforced Polymer (BFRP) composites have huge potential application respects for some civil fields due to enough strength/modulus to weight and low cost by replacing carbon fiber composites. Aiming at the issues in the Resin-Rich Region (RRR) and Interfacial Transition Region (ITR) of fiber reinforced polymer composites, the characteristic Aramid Pulp (AP) fibers with micro-fiber trunk and nano-fiber branches were manufactured into multiple non-woven ultra-thin interleaving at the interlayers of BFRP composites via compression molding to reinforce the flexural strengths and elastic moduli. AP fibers were introduced into RRR to form interleaving at the interlayer, the brittle epoxy adhesive layer was improved and enabled to avoid cracking under a low external load. Free fiber branches of AP were also embedded into BF layer to construct quasi-vertical fiber bridging behaviors in ITR, stronger mechanical interlocking was created to prevent crack propagation along the bonding interface of BF/epoxy. Three-point bending testing results showed the interleaving film with 4 g/m2 AP exhibited the best effect among various areal densities and yielded average 315.75 MPa in flexural strength and 21.38 GPa in elastic modulus, having a 63.4% increment and a 47.1% increment respectively compared with the bases. Overall, the simple and low-cost AP interleaving is confirmed as an effective method in improving interlayer structure and flexural performance of BFRP composites, which may be considered to manufacture high-performance laminated fiber reinforced polymer composites in civil aviation industry.

Bond-Slip Behaviors Between BFRP Bar and Ecological High Ductility Concrete Using the Beam Test

To better understand the design parameters of bridge deck link slab made by basalt fiber reinforced polymer (BFRP) bar and ecological high ductility concrete (Eco-HDC), the bond behaviors of BFRP bar embedded in Eco-HDC using beam test based on RILEM standard were studied. The beam specimens had variable factors namely diameter of BFRP bar, embedment length and cover thickness. The results indicate that most beam specimens display a failure mode of BFRP bar pulled out with specimen splitting. Besides, with the increase of diameter and embedment length, the bond strength decreases. While as the cover thickness increases, the bond strength and first bond stress show an increasing trend. The free end slip increases as the embedment length or cover thickness increases. In addition, the strain at loaded end is larger than that at free end as the load increases. Moreover, the formulas of bond strength and peak slip are proposed based on the test data of specimens. At last, embedment length and cover thickness of BFRP bar in the bridge deck link slab are recommended.