Enhanced Bond Strength Research Articles

Design of an alternating distributed large and small amounts of CNT/polyether amine coating on carbon fiber to derive enhancement in interfacial adhesion

In this paper, an innovative concept of alternating distributed large and small amounts of CNT/polyether amine coating is proposed to be wrapped around the carbon fiber via vacuum filtration. This coating feature is similar to “concave-convex” interval structure, which significantly distinguishes it from widely reported CNT coating with uniform encapsulation. The modified fiber reinforced epoxy composite presents a tremendous enhancement in interfacial bond strength reaching up to 81.8% relative to de-sized fiber composite. This increase comes from the synergistic effects of alternating distribution of strong-weak interactions that effectively dissipating energy, improved wettability, increased mechanical interlocking, as well as pinning and crack suppression effects of CNTs. The concept of interval distribution of large and small levels of coating has more possibilities for optimization. Thus, this unique coating structure, simple and flexible approach provides an attracting candidate for enhancing interphase performance of composites, also with the potential of practical and scalable.

Optimizing flexural cracking process of ultra-high performance concrete via incorporating microscale steel wires

Optimizing flexural cracking process is the premise to develop ultra-high performance concrete (UHPC) with high flexural strength and toughness as well as multiple cracking characteristics, and it was achieved by improving cracking resistance of matrix and forming complete multiscale fiber reinforcing network simultaneously in this study. Owing to their micro diameter and excellent elastic modulus as well as good thermal conductivity, microscale stainless steel wires at 0.2 vol% can already improve structure compactness of UHPC with straight mesoscale steel fibers by filling effect and reduce the microcracks caused by shrinkage and initial flexural load, thus enhancing the flexural-tensile modulus and initial macro cracking stress of composites. Meanwhile, the wires are conducive to increase fibers’ distribution and orientation with their high flexibility and form widely distributed network together with fibers to hinder cracks propagation, resulting in the occurrence of multiple cracking flexural failure and improved flexural properties of UHPC with less than 2.0 vol% fibers. Therefore, the enhancement of interfacial bond strength and first cracking energy via incorporating wires provide an approach for fabricating high ductile UHPC by maximizing the synergistic effectiveness of both wires and fibers.

Evaluation of bond behaviors on functionally graded ultra-high performance concrete (FGUHPC) subjected to elevated temperature

This paper designed a two-layered functionally graded ultra-high performance concrete (FGUHPC) member to meet the bearing and fire-resistant requirements subjected to elevated temperature, where the UHPC layer was used to bear loads and was protected by the lightweight aggregate concrete (LWAC) layer from high temperature. Debonding tests were conducted to evaluate its interfacial behaviors under ambient and high temperatures and the effect of cast-in bolts were investigated. The results showed that all specimens exhibited good fire-resistant behaviors, no visible cracks and spalling were observed for the UHPC layers while the LWAC layers maintained good integrality. Embedded bolts could significantly improve the initial stiffness, bond strength and post-peak ductility of specimens under direct tension at room temperature. The enhancement of bond strength was 40.0 % and 56.5 % when employing bolts with a diameter of 10 mm and 12 mm while that of ultimate displacement was 62.2 % and 58.1 % respectively compared with the specimens without bolts. In the case of high temperature, all specimens showed brittle failure, the bond strength obviously decreased and the effect of bolts on bond behaviors was insignificant due to the deterioration of the LWAC layers. All specimens without bolts showed debonding failure during the tests while the failure mode was converted from breakout to splitting or pullout for the specimens with bolts as the temperature increased.

The data-driven research on bond strength between fly ash-based geopolymer concrete and reinforcing bars

Bond strength between fly ash-based concrete (FGPC) and rebars is a vital index for ensuring the reliability and safety of reinforced concrete members. Thus, prediction and analysis of ultimate bond strength between FGPC and rebars are performed based on machine learning data-driven methods in this paper. A latest database including 137 samples from the published papers in the last decade is established. Four machine learning algorithms that include Lasso regression, Support Vector Regression (SVR), Random Forest (RF) and Extreme Gradient Boosting (XGB) are adopt for the construction of prediction models, and model evaluations are carried out by using four metrics (R2, RMSE, MAPE and MRE). The comparison between machine learning models and empirical models based on experiments is finished. Besides that, the feature importance is analyzed based on RF and XGB models. The results show that the machine learning models have a better prediction performance than the empirical models, where the RF and XGB models are optimal estimators with R2 of over 0.84 on testing set. Lasso and SVR models possess stronger generalization ability than RF and XGB models. The relatively important influence factors are compressive strength of FGPC (fc), reactivity modulus of precursors (RM), the ratio of cover thickness to diameter of rebar (c/d) and the ratio of anchorage length to diameter of rebar (l/d). Increasing slag content, fc, RM, and c/d are beneficial to enhancement of bond strength. The recommended values of fc, RM, c/d and l/d are 50 MPa, 0.7, 4.5 and 5.0 respectively.

An experimental study on interfacial bond strength between hybrid engineered cementitious composite and concrete

In this research, an experimental study was conducted to investigate the interfacial bond strength of polyvinyl-alcohol fibre reinforced engineered cementitious composite (PVA-ECC) and steel-polyvinyl alcohol hybrid fibre reinforced engineered cementitious composite (SPH-ECC) to compare the effects of using hybrid fibre ECC against mono-fibre ECC and aiming to promising and effective retrofitting material for reinforced concrete structures. Slant shear tests and splitting tensile tests were performed to study the shear bonding and splitting tensile bonding behaviours, respectively. The effect of surface roughness of the concrete surface on bond strength was also studied by measuring the bond strength of surfaces with different roughness under the As-Cast (AC) and Sandblasted (SB) surface treatment conditions. Interfacial surface roughness was measured using both quantitative and qualitative assessment methods. Experimental results obtained shown that sandblasting could greatly increase the roughness of concrete surfaces and lead to bond strength enhancement for both types of ECC-concrete interfaces. In addition, it was also found that for sandblasted surface, more significant increase was observed for the SPH-ECC interface due to dowel actions of the steel fibre. This indicated that SPH-ECC is a more suitable repairing/retrofitting material than PVA-ECC when sandblasting is applied. Finally, by using logarithmic regression, empirical relationships were proposed to predict the relationships of interfacial shear bond strength with the surface roughness of concrete.

Behaviour of EBRIG CFRP sheet-concrete joint: Comparative assessment with EBR and EBROG methods

• This study was the first attempt to evaluate the behavior of EBRIG FRP-concrete joints in comparison with EBR and EBROG joints. • A novel setup was developed to prepare the EBRIG specimens and carry the lap-shear tests on them. • The results including bond strength, failure modes, and other bond properties, confirmed the significant superiority of EBRIG installation method over the EBR and EBROG ones. • PIV technique was adopted to achieve the deformations fields and other bond properties. Grooving methods (GM) have remarkably shown higher efficiency than Externally Bonded Reinforcement (EBR) in anchoring the Fiber Reinforced Polymers (FRP) used for flexural retrofitting concrete structures. They are categorized into two types: Externally Bonded Reinforcement on Grooves (EBROG) and Externally Bonded Reinforcement In Grooves (EBRIG). The behavior of the EBR and EBROG joints were evaluated in many studies, but the behavior of EBRIG ones has not been assessed yet, and the present study is the first attempt to achieve the above aim. Accordingly, 12 concrete prisms were strengthened using one or two-layer of Carbon FRP (CFRP) sheets bonded via the EBR, EBROG, and EBRIG methods and then tested by a single lap-shear setup. In addition to evaluating bond strengths and failure modes, the bond behavior, including load-slip and shear stress-slip curves, and the slip, strain, and shear stress longitudinal profiles were acquired by Particle Image Velocimetry (PIV) technique. The results indicated substantial enhancement in the bond properties of specimens strengthened using grooving methods over the EBR. Besides, the EBRIG joint revealed a higher performance compared to the EBROG joint. For instance, applying the EBRIG method instead of EBROG led to 39% and 120% bond strength enhancement for one and two-layer FRP reinforced specimens, respectively. Additionally, all the EBROG joints failed due to cohesive debonding, whereas FRP sheets either ruptured or deeply debonded in the EBRIG joints reinforced with one or two layers of FRP.

Effect of nanosecond- and microsecond-pulse Er,Cr:YSGG laser ablation on dentin shear bond strength of universal adhesives.

The study aimed to evaluate the bond strength of universal adhesives to dentin after Er,Cr:YSGG laser irradiation with nanosecond-domain and microsecond-domain pulses. Eighty extracted caries-free, sound human molars were divided into eight groups. The enamel was removed until the dentin occlusal flat dentin surface was exposed. Etch-and-rinse followed by adhesive was applied to group 1, and a self-etch adhesive was applied to group 2. Er,Cr:YSGG laser (3mJ, 100Hz, 100ns), (3mJ, 100Hz, 150μs), and (20mJ, 100Hz, 150μs) were applied to groups 3-4, 5-6, and 7-8, respectively. The laser preparation was followed by self-etch adhesives or adhesives treatment. When the composite resin had been built up on the samples, the shear bond strength was tested, and the data were statistically analyzed using analysis of variance (ANOVA). Groups prepared with nanosecond-pulse laser showed significantly higher bond strength values than the microsecond-pulse laser groups and self-etch mode group, and the SEM photographs also showed more dentinal tubules and no damage in the ablation area. The shear bond strength of long pulse laser ablated was comparable to that of self-etching system when it was combined with a self-etch adhesive at low energy, but higher energy laser degraded shear bond strength. The pulse width of Er,Cr:YSGG laser affects the bond strength, nanosecond pulses of laser irradiation without water cooling can enhance bond strength, but microsecond pulses of laser cannot enhance bond strength.

Studies on Strength of Hollow concrete Block Masonry Externally Bonded with Textile Reinforced Mortar Composites

The aim of present study is to determine the mechanical properties of hollow concrete block masonry externally bonded with coir and glass textile reinforced mortar composites. The properties of textile composites were determined by testing TRM Coupons. A total number of 39 prisms were cast. The block masonry prisms were externally bonded with coir and glass textile fibre mesh with mortar. The elastic properties of block masonry, shear and flexural strength were determined for both unreinforced and strengthened specimens. The results showed that increasing the number of layers of textile fibers, enhanced the flexural capacity of TRM coupons. The provision of connectors also enhanced flexural strength. The stiffness of unreinforced masonry prisms was found to increase by strengthening with textile reinforcements even though the increase in compressive strength is marginal. There is a significant enhancement in flexural strength and shear bond strength when compared to unreinforced masonry.

Addition of metal chlorides to a HOCl conditioner can enhance bond strength to smear layer deproteinized dentin

ObjectivesTo evaluate the effect of smear layer deproteinization using hypochlorous acid (HOCl) with/without metal chlorides (SrCl2 and ZnCl2) on the microtensile bond strength (µTBS) of two simplified adhesives to dentin. MethodsHuman dentin surfaces with a standardized smear layer were pretreated using a 105 ppm HOCl solution with/without SrCl2 (0.05 M, 0.1 M, 0.2 M, 0.4 M) or ZnCl2 (0.05 M, 0.1 M, 0.2 M) for 5 s, 15 s, or 30 s. After the deproteinizing solution was washed out with water for 5 s, 15 s, or 30 s, pretreated surfaces were bonded with one-step self-etch adhesive Bond Force II or universal adhesive Clearfil Universal Bond Quick, and µTBS was measured after 24 h. Additionally, the deproteinizing effects of HOCl solutions with/without the metal chlorides were compared by measuring changes in the amide:phosphate ratio using attenuated total reflection Fourier transform infrared spectroscopy. Statistical analysis was performed using multifactor ANOVA, Tukey’s post hoc tests and t-tests (p < 0.05). ResultsPretreatment with pure HOCl for 15 s and 30 s significantly decreased the amide:phosphate ratio (p < 0.05), indicating effective deproteinization, but the µTBS of both adhesives increased significantly only if HOCl was washed out for 30 s (p < 0.05). Increasing the concentrations of metal chlorides enabled shortening of the wash-out time down to 5 s while maintaining the improved µTBS (p < 0.05). The deproteinizing effect of HOCl was not significantly altered by the addition of metal chlorides (p > 0.05). SignificanceThe effectiveness of smear layer deproteinization using HOCl can be improved by the addition of metal chlorides, as their increasing concentration allowed to shorten the wash-out time from 30 s down to 5 s

Bonding strength enhancement of low temperature sintered SiC power module by femtosecond laser induced micro/nanostructures

In this work, a low-temperature and low-pressure method was proposed for the bonding strength enhancement of SiC chips and substrates using micro/nanostructures fabricated by femtosecond laser. It is demonstrated that a reliable bond was achieved at 180 °C without assistant pressure. When the sintering temperature reached 250 °C and the assistant pressure was 10 MPa, the average shear strength reached 45 MPa, which was more than 3 times that of the flat substrate. The fracture surface morphology and the cross-section of the sample were characterized by SEM to analyze the enhancement mechanism of shear strength. The shear strength under different sintering conditions was also discussed. The thermomechanical coupled finite element simulation results demonstrate that the power module possessed excellent thermal capability and reliable lifetime under a temperature shock environment (−50 °C–250 °C). It is proved that the measured temperature distribution of the joint is in agreement with the simulation results. This method has great application prospects in microelectronic packaging, especially for wide-bandgap power semiconductors.

Improved bond strength, reduced porosity and enhanced mechanical properties of 3D-printed polyetherimide composites by carbon nanotubes

Fused deposition modelling (FDM) is one of the fastest-developing additive manufacturing approaches for printing polymers and composites. However, the existence of weak bond strength and high porosity is inevitable in 3D printed special engineering thermoplastics such as polyetherimide (PEI). In the present work, 3D printed carbon nanotube (CNT) reinforced PEI composites showed improved bond strength, reduced porosity and thus remarkably improved mechanical properties by introducing the CNTs. Specifically, the molten co-extrusion technique was employed to fabricate CNT/PEI composite filaments and then the FDM method was used to prepare CNT/PEI composite samples. Influences of CNT content on the tensile properties and microstructures were examined. Results showed that the incorporation of CNTs could improve the mechanical properties of 3D-printed CNT/PEI composites obviously due to the dramatic enhancement of bond strength and the significant reduction of porosity of 3D-printed CNT/PEI composite samples by introducing the CNTs. Furthermore, the incorporation of CNTs combined with annealing is beneficial to further enhancing the mechanical performance and reducing the warping of 3D-printed PEI samples.

In-vitro adhesive and interfacial analysis of a phosphorylated resin polyalkenoate cement bonded to dental hard tissues.

ObjectivesTo assess the performance of a novel resin-modified glass-ionomer cement (pRMGIC) bonded to various tooth tissues after two-time intervals. Methods192 sound human molars were randomly assigned to 3 groups (n = 64): sound enamel, demineralised enamel, sound dentine. Sixty-four teeth with natural carious lesions including caries-affected dentine (CAD) were selected. All substrates were prepared, conditioned and restored with pRMGIC (30% ethylene glycol methacrylate phosphate (EGMP, experimental), Fuji II LC (control), Fuji IX, and Filtek™ Supreme with Scotchbond ™ Universal Adhesive. Shear bond strength (SBS) was determined after 24 h and three months storage in SBF at 37 °C. The debonded surfaces were examined using stereomicroscopy and scanning electron microscopy (SEM). Multivariate Analysis of Variance (MANOVA), Bonferroni post hoc tests (alpha=0.05) and independent T-tests were used for multifactorial data analysis. ResultsThe hydrophilicity and functionality of EGMP enhanced the bond strength of the pRMGIC to different substrates after 24 h and 3 months as compared to F2LC (p<0.05). Adhesive failures were found to decrease with pRMGIC and integration into exposed enamel prisms and dentine tubules was observed with SEM. Ageing enhanced bond strength of pRMGIC to all substrates but was statistically significantly only in sound dentine. The SBS of pRMGIC was higher with sound vs. demineralised enamel at both time periods (p<0.001), while it was higher to CAD initially and to sound dentine post-storage (p = 0.004). ConclusionspRMGIC exhibited enhanced bonding performance to various tooth tissues with an ability to seal exposed enamel prisms and dentine tubules. Clinical significancepRMGIC is a promising material exhibiting long-lasting bonded-tooth interfaces, for its use in minimally invasive reparative techniques.

Study on the Applicability of Elastic Recovery (Resilience) Experiment for Asphalt-Rubber

In this paper, the applicability of the elastic recovery (resilience) experiment for asphalt-rubber (AR) binders has been quantitatively assessed. The mechanical model, based on the viscoelastic constitutive relation and particle inclusion theory, was developed. The interfacial detachment between crumb rubber (CR) particles and asphalt caused by stress concentration was analyzed with Weibull statistical equations. Based on the road roughness excitation, the vehicle-road coupling vibration model was established to analyze the impact of vehicle loading on road surface deformation. AR binders with different CR particle sizes were assessed using scanning electron microscope (SEM) imaging and prepared for testing the elastic recovery (resilience). The results showed that the greater internal stress caused by the longer stretch length of AR binders in the elastic recovery experiment was ten times higher than that obtained from the resilience experiment, leading to the interfacial detachment between asphalt and the CR particles. Hence, the elastic property of some of the CR particles with high modulus was not reflected, resulting in the test values being lower than actual values. With the reduction of CR particle size, the interfacial detachment was improved in the elastic recovery experiment due to intense material interchange and the enhancement of interfacial bond strength. The millimeter-scale compression deformation of the AR binder in the resilience experiment was closer to the actual deformation of the road surface. The experimental time of resilience (120 min) has been reported less than that for elastic recovery (200 min–230 min). This study shows that the resilience experiment has a significant advantage in assessing the elastic property of the AR binder.

Improvement of Quality of Life through Nanoparticles in Restorative Dentistry

Dental methods aimed at dental rehabilitation, regional anesthesia, orthodontic realigning, permanent hypersensitivity treatment, covalent bonding diamondized enamel, dental health preservation using mechanical dentifrobots, and the formation of artificial bone and teeth are among the possible uses of nanotools in dentistry. The evaluation and treatment of problems affecting the teeth and their surrounding tissues are the focus of restorative dentistry. For the restoration of tooth function and the repair and replacement of damaged tooth structures as well as better aesthetics, advanced procedures are required. In the past few years, resin-based dental restorative materials have made significant progress. Dental composite resin's mechanical performance, minimal polymerization contraction, strong wear resistance, and surface hardness can all be considerably improved by adding nanoparticles to the matrix. To date, nanocomposites for the repair of tooth structure have made one of the most significant contributions to restorative and cosmetic dentistry. Nanocomposites' characteristics aid in minimizing polymerization loss. Their microhardness is higher than that of already employed posterior resin-based composites, and the improved polishability properties in turn result in a smoother surface with better shade qualities. Nanocomposites have a number of benefits, including reduced weight, excellent thermal and electrical properties, antimicrobial activity, and the ability to remineralize dental defects. The other nanotools used in restorative dentistry are nanoadhesives, nanoionomers and nanoendodontic sealants. Nanoadhesives protect against failure of a restoration from bacterial invasion occurs due to spaces between restorative material and preparation margins. Nanoionomers chemically adhere to the surface of the tooth and offer advantages of enhanced bond strength, chemical stability, and insoluble nature. Nano endodontic sealers have the advantage of sealing better than conventional sealers and employing nanoparticles effectively acts as an antibacterial agent. Due to its potential uses and advantages, there is a growing demand for and interest in nano-based dental materials.

Impact of Various Cross Linking Agents on Dentin Adhesive Systems - an In-vitro Study

Aims and Objectives: The main aim of this study is to compare and evaluate the shear bond strength of composite resin using a total etch adhesive and self-etch adhesive after treatment with different collagen cross-linking agents.&#x0D; Materials and Methods: Forty freshly extracted human maxillary central incisors were taken. The proximal dentin was exposed, cavities were prepared on mesial and distal of each tooth. The specimens were randomly divided into two groups based on bonding agent applied-Group A and Group B i.e universal bonding agent and all in one bonding agent respectively and are subdivided into four groups based on the surface treatment of dentin. Group I A (n=10) Control-total etch(CTE); Group II A (n=10) Sodium Ascorbate-total etch (STE); Group III A (n=10)- Proanthocyanidin total etch(PTE); Group IV A (n=10)- Chitosan total etch (CHTE); Group I B (n=10) Control-self etch (CSE); Group II B (n=10) Sodium Ascorbate-self etch(SSE); Group III B (n=10)- Proanthocyanidin self-etch (PSE); and Group IV B (n=10) - Chitosan self-etch (CHSE). Shear bond strength of the specimens are tested with universal testing machine, and the data was statistically analysed with one way ANOVA.&#x0D; Results: Significantly higher shear bond strength to dentin was observed in teeth treated with 6.5% Proanthocyanidin Total etch, 10% Sodium Ascorbate Total etch and 1% Chitosan acetate compared to the control group. No significant difference was seen with self-etch treated groups.&#x0D; Conclusion: Dentin surface pretreatment with 6.5% Proanthocyanidin, 10% Sodium Ascorbate and 1% Chitosan acetate results in significant enhancement in bond strength of composite resin to deep dentin.

Experimental study on bonding behaviour of interface between UHPC and concrete substrate

The aim of this study is to investigate the effect of substrate surface roughness, fibre type, and water-to-binder ratio on the bond behaviour between ultra-high-performance concrete (UHPC) and normal-strength concrete (NSC). In addition, the suitability of different methods for evaluating the surface roughness using a sand-filling method, the height, number, and area of exposed coarse aggregates, and capillary absorption was verified. The results indicated that surface roughness was the most critical factor, followed by the water-to-binder ratio, and finally, the steel fibre type on influencing the bond strength. These methods for evaluating the surface roughness showed good consistency. The bond strength enhancement was mainly attributed to the compact transition zone of UHPC–NSC and the dowel effect of the steel fibres on the substrate surface recess. Based on the experimental bond strength values, an UHPC–NSC shear strength equation was derived, considering the repair surface roughness, and other research data verified the applicability of the proposed equation. Moreover, the NSC area fraction on the UHPC overlay side and the damage index of the composite specimen after debonding had a good linear relationship with the interface performance.

Enhancement of fabric\u2013mortar interfacial adhesion by particle decoration: insights from pull-off measurements

Polymer-impregnated carbon fabric is used as an alternative to metallic reinforcement bars in cementitious materials, which is then termed textile-reinforced concrete (TRC). In this study, the bond strength between the cement-based matrix and the fabric was enhanced by decorating the polymer (an epoxy) coating the carbon fabric with hydrophilic micron-size particles (cement or silica) or nanocarbons (functionalized carbon nanotubes or graphene oxide). Cement powder decoration led to a 25% increase in the bond strength (measured by a pull-off test) and a 30% improvement in the mechanical properties of the composite. At the micron scale, the decoration resulted in the formation of a 100-μm thick interlayer between the decorated fabric and the cement-based matrix. Unexpectedly, exposure of the cement-decorated samples to a NaCl environment (as in off-shore constructions) resulted in enhanced bond strength due to the growth of salt crystals at the fabric–matrix interface.

Bond Strength Analysis of Repaired Concrete based on Polymerization of Glycoluril Formaldehyde

Repairing old concrete include the correct choice of material and methodology adopted which may not affect the quality providing monolithic condition for old and new concrete. This study investigates two different parameters such as the impact as well as the optimum usage of new polymer glycoluril-formaldehyde as bonding material. Second one is about to understand the surface preparation for increased bonding strength at the interfacial area of old and new concrete. Five different types of surface textures are used to estimate the bond strength such as plane, lined, waved, grid and chipped. Glycoluril aids as a bonding material in both old and new concrete, and it is introduced at 0%, 1%, 2%, 3%, and 4% into the cement mixture. When the surface preparation creates a rough surface, it helps in repairing the concrete with the help of polymerization of glycoluril formaldehyde which promotes the enhancement of bond strength and slant shear. The bond strength of the specimens was measured by slant shear method in compression as well as tension for a period of 1, 2 and 4 weeks of new concrete. The results indicated that the highest bond strength was achieved in 3 percentage addition of glycoluril and grid patten substrate preparation.

Crack mitigation utilizing enhanced bond of rebars in SFRC

The bond of reinforcing bars in concrete can be enhanced by adopting steel fiber reinforced concrete (SFRC). In this research, cracking mitigation utilizing enhanced bond strength and stiffness in SFRC were analytically evaluated. Two values of secant bond stiffness, one at peak bond stress and the other at half peak bond stress, were determined from previous research and found to be each proportional to the bond strength. Comparison of bond strength and stiffness with these published in literature revealed variations. Lastly, mathematical analysis of the crack width in reinforced concrete member was performed. It was demonstrated that the increases in bond stiffness by up to 70% at a steel fiber volume of 2.0% could alleviate the mean crack width by 23% to 50%. More importantly, the rigorous analysis proved that the crack width is more directly related to the bond stiffness rather than the bond strength, suggesting that the bond stiffness plays a decisive role over the τb in crack control of FRC. The present research lays a scientific foundation for the development of fiber-rebar reinforced concrete (FRRC).

Bonding strength enhancement by Ag–Zn–Cu intermetallic compounds and microscale tapers array fabricated by femtosecond laser

Bonding strength enhancement by Ag–Zn–Cu intermetallic compounds and microscale tapers array fabricated by femtosecond laser