Exploring the Synergy: Experimental and Theoretical Investigation of Steel and Glass Fiber Reinforced Polymer (GFRP) Reinforced Slab Incorporating Alccofine and M-Sand

Introduction: This study investigates the Experimental and Theoretical Investigation of Steel and Glass Fiber Reinforced Polymer (GFRP) Reinforced Slab Incorporating Alccofine and M-sand. Objective: Specific objectives include evaluating the mechanical properties and structural behaviour of steel and GFRP-reinforced one-way slabs and comparing experimental and theoretical predictions. Methods: Four different mix proportions were arrived at, comprising both conventional concrete and Alccofine-based concrete. In each formulation, a combination of normal river sand and M-sand was utilized. Results: Concrete with Alccofine exhibits superior mechanical properties, while M-sand incorporation minimally affects strength but reduces reliance on natural sand. GFRP-reinforced slabs display distinct brittle behaviour with significant deflections post-cracking, contrasting steel-reinforced slabs’ gradual, ductile failure. Discrepancies between experimental data and design recommendations underscore the need for guideline refinement. Conclusion: Alccofine and M-sand enhance concrete properties, but reinforcement type significantly influences slab behaviour. GFRP-reinforced slabs, though exhibiting lower values than steel, offer advantages in harsh environments, warranting further optimization.

Bond Performance of Fiber Reinforced Polymer （FRP） Bars in Autoclaved Aerated Concrete （AAC）

This paper concerns the bond strength of FRP bars in AAC by the concentric pullout test. Specimens were subjected to compare with mild steel bars. The bond performance including the mode of failure and bond strength was investigated with varying embedment length and surface treatment. Regarding the bond performance, embedment depth has influenced on bond strength as well as the sanded surface. Carbon fiber reinforced polymer （CFRP） pronounced the most promising results with the highest bond strength attained.

Compressive properties of glue-laminated timber circular post modified by basalt fiber reinforced polymer

Glued timber structure is one of the main forms of modern wood architecture,which has gradually developed towards mid-and high-rise buildings.Glue-laminated timber(GLT)is comprised of several laminates of parallel-to-grain dimension lumber that are bonded together with durable,moisture resistant structural adhesives.GLT can be used in horizontal applications as a beam and in vertical applications as a post.So,its compressive performance has a significant impact on structural safety.Fiber reinforced polymers(FRPs)were commonly used to improve the bearing capacity of GLT components,and the structural and process parameters largely determined the reinforcement effect.This study was aimed at investigating the influence of structural and process parameters on the axial compression performance of GLT components.Three wrapping methods(middle-part,end-part and full wrapping)and three lengths(0.6,0.8,and 1.0 m)of wood post specimens were designed in this work and the axial compression performance and ductility of GLT post specimens modified by basalt fiber reinforced polymer(BFRP)were studied.The results showed that the effect of different BFRP wrapping methods on the compressive strength and elastic modulus of laminated wood was not statistically significant(P>0.05).The compressive bearing capacity of unreinforced GLT posts decreased with the increase of aspect ratio.The GLT posts with middle-part and end-part wrapping still followed this pattern,while the compressive bearing capacity of GLT posts with full wrapping showed a pattern of first decreasing and then increasing.For GLT with low aspect ratios(4.0 or 5.3),there was no correlation between the wrapping method and the compressive bearing capacity,while the compressive bearing capacity of GLT with a high aspect ratio(6.7)for middle-part,end-part and full wrapping increased by 3.5%,7.5%and 9.7%,respectively.Compared to the unreinforced group,the ultimate axial compressive strength and modulus of elasticity(MOE)of the 6-E series specimens reinforced at both ends decreased by 2.58%and 6.70%,respectively.The ultimate axial compressive strength of the 8-E specimens reinforced at both ends increased by 8.62%and the MOE decreased by 1.91%.The compressive strength of the 10-E specimens reinforced at both ends increased by 7.51%and the MOE increased by 8.14%.The failure modes of GLT with different aspects were consistent under the same BFRP wrapping,while the failure modes of GLT with the same aspect ratio were different for different BFRP wrapping methods.The ductility performance of GLT with different aspects ratio was improved by the BFRP wrapping.

A review on machinability of carbon fiber reinforced polymer(CFRP)and glass fiber reinforced polymer(GFRP)composite materials

Fiber reinforced polymer(FRP) composite materials are heterogeneous and anisotropic materials that do not exhibit plastic deformation. They have been used in a wide range of contemporary applications particularly in space and aviation,automotive,maritime and manufacturing of sports equipment. Carbon fiber reinforced polymer(CFRP) and glass fiber reinforced polymer(GFRP) composite materials,among other fiber reinforced materials,have been increasingly replacing conventional materials with their excellent strength and low specific weight properties. Their manufacturability in varying combinations with customized strength properties,also their high fatigue,toughness and high temperature wear and oxidation resistance capabilities render these materials an excellent choice in engineering applications.In the present review study,a literature survey was conducted on the machinability properties and related approaches for CFRP and GFRP composite materials. As in the machining of all anisotropic and heterogeneous materials,failure mechanisms were also reported in the machining of CFRP and GFRP materials with both conventional and modern manufacturing methods and the results of these studies were obtained by use of variance analysis(ANOVA),artificial neural networks(ANN) model,fuzzy inference system(FIS),harmony search(HS) algorithm,genetic algorithm(GA),Taguchi's optimization technique,multi-criteria optimization,analytical modeling,stress analysis,finite elements method(FEM),data analysis,and linear regression technique. Failure mechanisms and surface quality is discussed with the help of optical and scanning electron microscopy,and profilometry. ANOVA,GA,FEM,etc. are used to analyze and generate predictive models.

Compressive Strength Estimation for the Fiber-Reinforced Polymer (FRP)-Confined Concrete Columns with Different Shapes Using Artificial Neural Networks

An evaluation of existing strength of concrete columns confined with fiber-reinforced polymer( FRP) was presented with extensive collection of experimental data. According to the evaluation results, artificial neural networks( ANNs) model to predict the ultimate strength of FRP confined column with different shapes was proposed. The models had seven inputs including the column length,the tensile strength of the FRP in the hoop direction,the total thickness of FRP,the diameter of the concrete specimen,the elastic modulus of FRP,the corner radius and the concrete compressive strength. The compressive strength of the confined concrete was the output data. The results reveal that the proposed models have good prediction and generalization capacity with acceptable errors.

Shear Strength Evaluation of Concrete Beams Reinforced with BFRP Bars and Steel Fibers without Stirrups

This paper presents experimental and analytical investigations on concrete beams reinforced with basalt fiber reinforced polymer(BFRP)and steel fibers without stirrups.Independent behaviour of BFRP reinforced beams and steel fiber reinforced beams were evaluated and the effect of combining BFRP bars and steel fiber was investigated in detail.It is found that combining s teel fibers with BFRP could change the shear failure of BFRP reinforced beam to flexural failure.Further,the existing analytical models were reviewed and compared to predict the shear strength of both FRP reinforced and steel fiber reinforced beams.Based on the review,the appropriate model was chosen and modified to predict the shear strength of BFRP reinforced beam along with steel fibers.

Parameters of static response of carbon fiber reinforced polymer(CFRP) suspension cables

The feasibility of longer spans relies on the successful implementation of new high-strength light weight materials such as carbon fiber reinforced polymer(CFRP). First, a dimensionless equilibrium equation and the corresponding compatibility equation are established to develop the cable force equation and cable displacement governing equation for suspension cables, respectively. Subsequently, the inextensible cable case is introduced. The formula of the Irvine parameter is considered and its physical interpretation as well as its relationship with the chord gravity stiffness is presented. The influences on the increment of cable force and displacement by λ2 and load ratio p′ are analyzed, respectively. Based on these assumptions and the analytical formulations, a 2000 m span suspension cable is utilized as an example to verify the proposed formulation and the responses of the relative increment of cable force and cable displacement under symmetrical and asymmetrical loads are studied and presented. In each case, the deflections resulting from elastic elongation or solely due to geometrical displacement are analyzed for the lower elastic modulus CFRP. Finally, in comparison with steel cables, the influences on the cable force equation and the governing displacement equation by span and rise span ratio are analyzed. Moreover, the influences on the static performance of suspension bridge by span and sag ratios are also analyzed. The substantive characteristics of the static performance of super span CFRP suspension bridges are clarified and the superiority and the characteristics of CFRP cable structure are demonstrated analytically.

Application of Glass Fiber Reinforced Polymer Composite (GFRPC) Escape Pipeline in Tunnel

During the tunnel construction process,unfavorable geological conditionsare often encountered.Geological disasters such as collapse,roof fall,water inrush,gas explosion,etc.occur frequently,causing different degrees of property damage and casualties to the construction of the tunnel,seriously affecting harmony during construction.The domestic emergency hedging is mainly the use of 8-10mm steel coils,but the steel is heavy and not suitable for the frequent movement of tunnels.This paper introduces the new Glass Fiber Reinforced Polymer Composite(GFRPC)escape pipeline used in Chongqing Jiuyongyi Jinyunshan Tunnel,and compares the traditional steel coil parameters to provide reference for subsequent tunnel hedging measures.

Deriving Tensile Properties of Glass Fiber Reinforced Polymers (GFRP) Using Mechanics of Composite Materials

This work addresses the tensile properties of glass fiber reinforced polymers (GFRP) and investigates the different ways of estimating them without the cost associated with experimentation. This attempt is achieved through comparison between experimental results, derived in accordance with the ASTM standards, and results obtained using the mechanics of composite materials. The experimental results are also compared to results derived from work by other researchers in order to corroborate the findings regarding the correlation of tensile properties of the GFRP material and the fiber volume fraction.

Fatigue behavior of basalt-aramid and basalt-carbon hybrid fiber reinforced polymer sheets

In order to study the fatigue failure mode and fatigue life laws of basalt-aramid and basalt-carbon hybrid fiber reinforced polymer （ FRP ） sheets, fatigue experiments are carried out, considering two hybrid ratios of 1 ： 1 and 2：1 under different stress levels from 0.6 to 0.95. The results show that fractures occur first in carbon fibers or aramid fibers for the specimens with hybrid ratio of 1： 1, namely B1A1 and B1C1, while a fracture occurs first in basalt fibers for the specimens with a hybrid ratio of 2： 1, namely B2A1 and B2C1. The fatigue lives of the hybrid FRP sheets increase with the improvement of the content of carbon fibers or aramid fibers, and the influence of the carbon fibers content improvement to fatigue life is more significant. The fatigue performance of B2A1 is relatively worse, while the fatigue performance of B1C1 and B2C1 is relatively better. Finally, a new fatigue stiffness degradation model with dual variables and double inflection points is presented, which is applicable to both hybrid and normal FRP sheets.

Seismic strengthening of reinforced concrete columns damaged by rebar corrosion using combined CFRP and steel jacket

In order to study the effectiveness of combined carbon fiber-reinforced polymer （CFRP） sheets and steel jacket in strengthening the seismic performance of corrosion-damaged reinforced concrete （RC） columns, twelve reinforced concrete columns are tested under combined lateral cyclic displacement excursions and constant axial load. The variables studied in this program include effects of corrosion degree of the rebars, level of axial load, the amount of CFRP sheets and steel jacket. The results indicate that the combined CFRP and steel jacket retrofitting technique is effective in improving load-carrying, ductility and energy absorption capacity of the columns. Compared with the corrosion-damaged RC column, the lateral load and the ductility factor of many strengthened columns increase more than 90% and 100%, respectively. The formulae for the calculation of the yielding load, the maximum lateral load and the displacement ductility factor of the strengthened columns under combined constant axial load and cyclically increasing lateral loading are developed. The test results are also compared with the results obtained from the proposed formulae. A good agreement between calculated values and experimental results is observed.

Constitutive modeling of viscoelastic-viscoplastic behavior of short fiber reinforced polymers coupled with anisotropic damage and moisture effects

In this paper, a combined viscoelasticity-viscoplasticity model, coupled with anisotropic damage and moisture effects, is developed for short fiber reinforced polymers (SFRPs) with different fiber contents and subjected to a variety of strain rates. In our model, a rate-dependent yield surface for the matrix phase is employed to identify initial yielding of the material. When an SFRP is loaded at small deformation before yielding, its viscoelastic behavior can be described using the generalized Maxwell model, while when plasticity occurs, a scalar internal state variable (ISV) is used to capture the hardening behavior caused by the polymeric constituent of the composite. The material degradation due to the moisture absorption of the composite is modeled by employing another type of ISV with different evolution equations. The complicated damage state of the SFRPs is captured by a second rank tensor, which is further decomposed to model the subscale damage mechanisms of micro-voids/cracks nucleation, growth and coalescence. It is concluded that the proposed constitutive model can be used to accurately describe complicated behaviors of SFRPs because the results predicted from the model are in good agreement with the experimental data.

Strengthening reinforced concrete beams using prestressed glass fiber-reinforced polymer-Part I: Experimental study

This work is aimed at studying the strengthening of reinforced concrete (R. C.) beams using prestressed glass fi- ber-reinforced polymer (PGFRP). Carbon fiber-reinforced polymer (CFRP) has recently become popular for use as repair or rehabilitation material for deteriorated R. C. structures, but because CFRP material is very stiff, the difference in CFRP sheet and concrete material properties is not favorable for transferring the prestress from CFRP sheets to R. C. members. Glass fi- ber-reinforced polymer (GFRP) sheets with Modulus of Elasticity quite close to that of concrete was chosen in this study. The load-carrying capacities (ultimate loads) and the deflections of strengthened R. C. beams using GFRP and PGFRP sheets were tested and compared. T- and ⊥-shaped beams were used as the under-strengthened and over-strengthened beams. The GFRP sheets were prestressed to one-half their tensile capacities before being bonded to the T- and ⊥-shaped R. C. beams. The prestressed tension in the PGFRP sheets caused cambers in the R. C. beams without cracks on the tensile faces. The PGFRP sheets also enhanced the load-carrying capacity. The test results indicated that T-shaped beams with GFRP sheets increased in load-carrying capacity by 55% while the same beams with PGFRP sheets could increase load-carrying capacity by 100%. The ⊥-shaped beams with GFRP sheets could increase load-carrying capacity by 97% while the same beams with PGFRP sheets could increase the loading-carrying capacity by 117%. Under the same external loads, beams with GFRP sheets underwent larger deflections than beams with PGFRP sheets. While GFRP sheets strengthen R. C. beams, PGFRP sheets decrease the beams’ ductility, especially for the over-strengthened beams (⊥-shaped beams).

Water-induced changes in strength characteristics of polyurethane polymer and polypropylene fiber reinforced sand

As a new kind of air-hardening soil reinforcement material,polymer is being widely applied in river-bank slope reinforcement and ecological slope protection area.Thus,more attention should be paid to study the characteristics of reinforced soil after immersion.In this study,water-induced changes in strength characteristics of sand reinforced with polymer and fibers were reported.Several factors,including polymer content(1%,2%,3%and 4%by weight of dry sand),immersion time(6,12,24 and 48 h),dry density(1.40,1.45,1.50,1.55 and 1.60 g/cm^(3),)and fiber content(0.2%,0.4%,0.6%and 0.8%by weight of dry sand)which may influence the strength characteristics of reinforced sand after immersion were analyzed.The microstructure of reinforced sand was analyzed with nuclear magnetic resonance(NMR)and scanning electron microscope(SEM).Experimental results indicate that the compressive strength increases with the increase of polymer content and decreases with the increase of immersion time;the softening coefficients decrease with the increase of the polymer content and immersion time and increase with an increment in density and fiber content.Fiber plays an active role in reducing water-induced loss of strength at 0.6%content.

Mechanical joint performances of friction self-piercing riveted carbon fiber reinforced polymer and AZ31B Mg alloy

Carbon fiber reinforced polymer(CFRP) and AZ31B Mg alloy were joined by the friction self-piercing riveting(F-SPR) with different steel rivet shank sizes. With the increase of rivet shank size, lap shear fracture load and mechanical interlock distance increased. Ultrafine grains were formed at the joint in AZ31B as a result of dynamic recrystallization, which contributed to the higher hardness. Fatigue life of the CFRP-AZ31B joint was studied at various peak loads of 0.5, 1, 2, and 3 kN and compared with the resistance spot welded AZ31B-AZ31B from the open literature. The fatigue performance was better at higher peak load(>2 kN) and comparable to that of resistance spot welding of AZ31B to AZ31B at lower peak loads(<1 kN). From fractography, the crack initiation for lower peak load(<1 kN) case was observed at the fretting positions on the top and bottom surfaces of AZ31B sheet. When peak load was increased, fretting between the rivet and the top of AZ31B became more dominant to initiate a crack during fatigue testing.

Study of galvanic corrosion and mechanical joint properties of AZ31B and carbon-fiber–reinforced polymer joined by friction self-piercing riveting

A new testing methodology was developed to quantitively study galvanic corrosion of AZ31B and thermoset carbon-fiber–reinforced polymer spot-joined by a friction self-piercing riveting process.Pre-defined areas of AZ31B in the joint were exposed in 0.1 M NaCl solution over time.Massive galvanic corrosion of AZ31B was observed as exposure time increased.The measured volume loss was converted into corrosion current that was at least 48 times greater than the corrosion current of AZ31B without galvanic coupling.Ninety percent of the mechanical joint integrity was retained for corroded F-SPR joints to 200 h and then decreased because of the massive volume loss of AZ31B。

Electron density measurement of laser-induced epoxy fiber reinforced polymer plasma

Interferograms of laser-induced epoxy fiber reinforced polymer plasmas are obtained through aMach-Zehnder interferometry system. An improved digital double-exposure Fourier method is applied to extractinitial wrapped phases from interferograms, and then an improved phase unwrapping algorithm based on a maskand a branch-cut method is proposed to solve the problem of phase unwrapping. After the inverse Abel transfor-mation of the unwrapped phase, spatial distributions of the electron density of laser-induced epoxy fiber rein-forced polymer plasma at various delays are acquired. Results show that the measured electron density of theplasma is mainly distributed on the order of 10^18 cm^3. The experiment also indicates that the total amount oflaser plasma electrons changes slightly within the recorded time and the change of the electron density is approx-imately inversely proportional to the change of the plasma volume.

A Review on Strengthening of Timber Beams Using Fiber Reinforced Polymers

Fiber reinforced polymer(FRP)has been used in the construction industry because of its advantages such as high strength,light weight,corrosion resistance,low density and high elasticity.This paper presents a review of bonding techniques adopted to strengthen timber beams using FRP to achieve larger spans.Different methods of bonding between FRP and timber beams have been summarized with a focus on the influencing factors and their effects as well as relevant bond-slip models proposed for fundamental understanding.Experimental investigations to evaluate the flexural performance of timber beams strengthened by FRP bars,sheets and wraps have also been critically reviewed to identify key influencing parameters.Limited research available on the shear performance of FRP reinforced timber beams have been analyzed to determine the influencing factors of the shear performance in timber-FRP beams.The paper finally presents an overall summary of the current-state-of-the-art and proposes some future research directions in the field.

Experimental Investigation of Natural Fiber Reinforced Polymers

The potential usage of virgin Low density polyethelyne (LDPE) reinforced with different concentrations (2%, 5% and 6% by weight) of treated rice straw with different lengths (2 mm, 4 mm and 6 mm) is investigated to produce high value products that have technical and environmental demand. The two treatment methods used for rice straw are alkali and acidic treatments of rice straw. The removal of impurities and waxy substances from fiber surface avoid creation of rougher topography after treatment and improves the quality of fiber, also content of hemi cellulose and lignin decrease so increase effectiveness of fiber due to dispersing of fiber in matrix. The reinforcing material is embedded in the matrix material to enhance tensile and flexural behaviors of the synthesized composite. The result of investigating these two mechanical properties, using statistical analysis & design of experiments, showed an enhancement in the mechaniccal properties of the virgin polymer composite compared to the virgin polymer. The flexural stress of the composite increased three times the virgin flexural stress, while the tensile stress increased eight times the original tensile stress.