Glass Fiber Reinforced Polymer Concrete Research Articles

Seismic performance of a GFRP–concrete–steel hollow section segmental column with SMA bars and replaceable ED devices

This paper investigates the seismic behavior of a novel precast segmental bridge column (PSBC). Glass fiber reinforced polymer (GFRP)-concrete-steel hollow section segments were used to construct the column. Hybrid energy dissipation (ED) system consisted of shape memory alloy (SMA) bars and replaceable external ED devices was proposed to increase the ED capacity of the PSBC. The SMA bars have a large deformation capacity, which makes them not easy to be damaged. They were therefore installed inside the column to absorb energy and more importantly to keep the residual displacement small. External ED devices were used to increase the overall ED ability of the PSBC. The external arrangement of the ED devices made it possible and easy for the post-earthquake replacement. A reference PSBC with steel-reinforced precast segments was also constructed and investigated. The test results demonstrated that, compared with the traditional PSBC, the proposed column exhibited appealing seismic performance, including better self-centering capacity, higher post-yield stiffness, and better ED ability. Furthermore, the proposed PSBC experienced minimal concrete damage during the test. One of the external ED devices fractured, however, they could be uninstalled and replaced easily. Numerical models were developed and used to conduct parametric studies. The results demonstrated the feasibility of using the hybrid ED system and the GFRP–concrete–steel​ hollow section segments to improve the performance of the PSBC under seismic loadings.

Short glass fiber reinforced polymer concrete with addition of waste cathode-ray tube (CRT) glass

This paper describes the use of CRT glass waste for the production of polymer concrete. The CRT glass was subjected to a multistage mechanical disintegration process, in a way that allowed obtaining grains smaller than 2 mm. A set of hybrid reinforced polymer concrete was produced by using: ground CRT glass, sand and cut glass fibers 4.5 mm and 12 mm long. The influence of the volume of fibers and the length of glass fibers on the properties of polymer concrete with 30% by volume of epoxy resin, acting as a binder was described. Tests of CRT glass were carried out, among others study of chemical composition, particle size distribution and analysis of grain morphology. For polymer concrete, the flexural strength and compressive strength were determined, and the open porosity, apparent density, and water absorption were examined. The test results showed that polymer concrete with the use of milled CRT glass is a good way to manage this problematic waste. The polymer concrete has several times better than traditional concretes and significantly lower porosity and water absorption, which makes this material advantageous in applications such as the production of thin-walled products and products exposed to water and chemical attack. The addition of chopped glass fibers leads to an increase in mechanical properties and also protects the material against rapid disintegration after exceeding the maximum tresses, which is extremely important for the safety of use of the structure in the event of a failure.

Strain-hardening fiber reinforced polymer concrete with a low carbon footprint

Epoxy resin, fly ash, and silica sand were used to produce polymer concrete reinforced with glass, carbon, polyvinyl alcohol (PVA), and high strength steel micro-fibers. The effects of two resin contents: 15% and 18%, and two curing regimes: ambient and heat were assessed. Their compressive strength, permeable porosity, and uniaxial tensile stress–strain behavior were studied. The compressive strength of 15% and 18% polymer concrete were 48–62 MPa and 61–74 MPa respectively. The porosity of all types of polymer concretes was less than 1%, except 15%-PVA and 15%-glass fiber reinforced polymer concrete. Under uniaxial tensile loading, glass and carbon fiber reinforced polymer concrete portrayed a sudden brittle failure resulting from complete fiber rupture, whereas PVA and steel fiber reinforced polymer concrete demonstrated a ductile strain-hardening response. A significantly higher tensile strength was observed when the resin content was increased from 15% to 18%, particularly for glass and carbon fiber reinforced polymer concrete, whereas for PVA and steel fiber reinforced polymer concrete this improvement was small. The brittle carbon fiber reinforced polymer concrete demonstrated the highest tensile strength, whereas the ductile steel fiber reinforced polymer concrete had the highest post-crack residual strength at large strains, irrespective of the resin content. Overall, heat curing had no impact on compressive or tensile properties of any type of polymer concrete investigated.

Concrete wedge and coarse sand coating shear connection system in GFRP concrete composite deck

In recent years, Glass Fiber-Reinforced Polymer (GFRP) has become a widely used material in Fiber-Reinforced Polymer (FRP) composite structures. Several studies have been performed on the bonding methods of FRP sheets and plates, but limited research has been undertaken on the critical shear connection systems for innovative GFRP concrete composite bridge decks structures. Coarse sand coating shear connection systems for GFRP structures show strong bondage in the shear direction but poor grip in the normal direction. An innovative concrete wedge system, supplementary to coarse sand coating overcomes the normal split between GFRP panel and concrete, in composite bridge deck structures. This study presents a finite element (FE) investigation on GFRP concrete composite deck using a concrete wedge shear connection system based on existing experimental evaluation. In this research, the thickness of the GFRP module was varied and the deflection behaviour of GFRP concrete composite deck was furthermore studied. FE results indicate that thickness increments of the GFRP module significantly reduce the mid-span deflection of the composite deck and subsequently increase the ultimate load. In order to investigate the interaction behaviour between GFRP and concrete in the numerical analysis, a structural interface element is proposed for finite element modelling (FEM) analysis. In order to undertake a rapid evaluation of deflection of the composite deck, an equation is proposed to estimate the deflection at the mid-span of the GFRP composite bridge deck based on the FEM results. In addition, the GFRP composite bridge deck was numerically analysed using light-weight concrete (LWC) and results were compared with GFRP composite deck with conventional concrete. The results indicate that using LWC increases the ultimate load proportionally till failure.

Forming Process and Mechanical Properties of Fiber Reinforced Polymer Concrete for Elementary Machine Parts

For the good vibration alleviating properties, polymer concrete (PC) has attracted much attention in the field of elementary machine components. In order to get more excellent mechanical properties, the forming process and mechanical properties of PC were concerned. In this research, glass fiber and carbon fiber were applied to improve the mechanical properties of PC. A series of PC and fiber reinforced polymer conctete (FRPC) specimens were prepared basing on the orthogonal tables for property test. Compression strength test was carried out. It is obvious that FRPC is better than PC as far as compression strength is concerned, and carbon fiber reinforced polymer concrete (CFRPC) is better than glass fiber reinforced polymer concrete (GFRPC). Trend curves about the relationship between fiber length and compression strength, as well as that between fiber dosage and compression strength were drawn. Relationship between the considered factors and compression strength is analyzed basing on the experiment results and the trend curves. Strengthening fibers would bear most of the internal stress when the specimen is faced to outer loads. Thus, FRPC has much better properties than PC. Mechanical properties of CFRPC are relatively better than that of GFRPC, for the strength of carbon fiber is better than that of glass fiber. It could be concluded that glass fiber is the proper strengthening fiber for PC considering both technical and economical factors.

Forming process and mechanical properties of fibers-reinforced polymer concrete

For good vibration alleviating properties, polymer concrete has attracted much attention in the field of elementary machine components. In this article, glass fiber and carbon fiber were applied to improve the mechanical properties of polymer concrete. Seen from the experimental results, as far as compression strength is concerned, fiber-reinforced polymer concrete is better than polymer concrete, and carbon fiber-reinforced polymer concrete is better than glass fiber reinforced polymer concrete. However, considering both technical and economical factors, it could be concluded that glass fiber is the proper strengthening fiber for polymer concrete.

Fracture behavior of textile glass fiber reinforced polymer concrete according to mixed-mode

Textile glass fiber reinforced particle-filled polymer composite beams which have different weight fractions of glass fibers were produced with varying notch-to-depth ratios. The mechanical properties of specimens were found. The specimens were investigated in Mode I and Mode III fracture behavior using three-point bending (TPB) tests. Textile glass fiber contents used were 1, 2 and 3%, and polyester content was 16.5% of the total weight of the polymer composite system. The critical stress intensity factor was determined by using a compliance technique, the initial notch depth method and the J-integral method. Effects of crack angles on fracture behavior were also studied. The specimens, which have an inclined crack at an angle θ to the axis of the specimens, were used to carry out the tests. The specimens were tested with inclination angles 30°, 45°, 60° and 75°. The results are compared with the values of KICobtained using conventional (θ = 90°) specimens. In addition, J-integrals were also determined.

Study on vibration alleviating properties of glass fiber reinforced polymer concrete through orthogonal tests

Polymer concrete (PC), because of its good vibration alleviating properties, is a proper material for elementary machine parts in high-precision machine tools. Glass fiber was applied in PC to improve its mechanical properties, and the material obtained is called glass fiber reinforced polymer concrete (GFRPC). The best parameter to estimate the vibration alleviating property is damping ratio. Orthogonal tests were carried out to prepare GFRPC specimens with different component proportions. Damping ratio of the GFRPC specimens was measured. The effect of the factors considered in the experiments on damping ratio of GFRPC was studied. Results of the tests show that granite proportion plays the most important role in determining damping ratio of GFRPC, then flexibilizer dosage and glass fiber length, while epoxy resin dosage and glass fiber dosage play a comparatively less important part. Detailed descriptions were made about how the considered factors affect damping ratio of GFRPC in this paper.

Freeze–thaw and thermal degradation influence on the fracture properties of carbon and glass fiber reinforced polymer concrete

In recent years, it has been found that some concrete structures, even for some high performance concrete and ready mixed concrete under good quality control, start to deteriorate long before reaching their designed service life. Cracks are found after the structure has been completed for a few years, which results in the shortening of service life and lowering in durability. In this paper, the influence on the fracture properties of fiber reinforced polymer concrete, FRPC, subjected to freeze–thaw and thermal degradation, is discussed. The study on the damage influence was conducted using a climate chamber to perform the temperature changes on the single edge notched beams. FRPC specimens were subjected to freeze–thaw and higher temperature cycles and then tested according to RILEM standards. To determine the stress intensity factor, K Ic, critical crack tip opening displacement CTODc, the Two Parameter Method was used and the fracture energy, G f of the specimens was calculated to evaluate the fracture properties of FRPC. Three-point bending tests were carried out on notched beams with a clip gauge attached to measure the crack mouth opening displacement CMOD. Polymer concrete was reinforced with short glass and carbon fiber with 1% and 2% in mass respectively, to determine whether the reinforcement increases the performance of the material. The fracture properties of FRPC are reported in such conditions.

Mixed-mode fracture behavior of glass fiber reinforced polymer concrete

Fracture toughness of chopped strand glass fiber reinforced particle-filled polymer composite beams was investigated in Mode I and Mode III loading conditions using three-point bend tests. Effects of crack angles on fracture behavior were also studied. The specimens, which have inclined crack at an angle θ to the axis of the specimens, were used to carry out the tests. The specimens were tested with inclination angles 30°, 45°, 60° and 75°. The results are compared with the values of K IC obtained using conventional ( θ=90° ) specimens. In addition, J integrals were also determined. J IC increases continuously with increasing in crack angle from θ=30° to θ=90°. In contrast, J IIIC decreases with the crack inclination angle θ from 30° to 90°.

Fracture behavior of glass fiber reinforced polymer concrete

Polymer concrete, is a composite material formed by polymerizing a monomer and an aggregate mixture. The polymerized monomer acts as the binder for the aggregates. Initiators and promoters are added to the resin prior to its mixing with the inorganic aggregates to initiate the curing reaction. Fracture behavior of chopped glass fiber reinforced polymer concrete was investigated in this study using the two-parameter model, according to RILEM recommendations. This is a direct method to calculate the flexural modulus of elasticity and two size-independent fracture parameters, i.e., the critical stress intensity factor, K IC, and the crack tip opening displacement (CTOD). Beams with a central notch were tested under three-point bending using an attached clip gauge to measure the CTOD. The chopped glass fibers used were 6 and 25 mm long. The fibers were also pre-treated to improve the adhesion between fibers and resin and fracture properties. In general, addition of fibers increases flexural strength and fracture properties of polymer concrete. The modulus of elasticity of glass fiber polymer concrete can increase by up to 39%. The object of this research work is to evaluate the influence of fibers on the mechanical and fracture properties of polymer concrete. This paper is a new contribution to a research field with a very small number of publications.