Interfacial Bond Strength Research Articles

Influence of different intraradicular chemical pretreatments on the bond strength of adhesive interface between dentine and fiber post cements: A systematic review and network meta-analysis.

Systematic review and network meta-analyses were performed to answer the question: Do intraradicular chemical pretreatments affect the bond strength of the adhesive interface between dentine and fiber post cements? A literature search was performed in PubMed, Scopus, Web of Science, LILACS, BBO, and Cochrane Library in October 2018 (updated September 2021). In vitro studies that compared the bond strength assessed by push-out tests following at least two dentine chemical treatments prior to fiber post cementation were included. Risk of bias was evaluated. A random-effects Bayesian-mixed treatment comparison model was used to compare push-out bond strength of different chemical pretreatments. SUCRA (surface area under the cumulative ranking) analysis was performed to rank the pretreatments. After removing duplicates and screening titles and abstracts, 61 studies remained. SUCRA analysis showed that the best bond strength values for self-etch, etch-and-rinse, and self-adhesive cements were ethyl acetate (SUCRA: 99.8%), low concentration NaOCl (SUCRA: 83.4%), and grape seed extract (SUCRA: 97.6%), respectively. According to the SUCRA rankings, ethanol was in a good position for all adhesive strategies (SUCRA: 78.6%). The use of chemical pretreatments in intraradicular dentine of endodontically treated teeth depends on the adhesive and cementation strategy. The pretreatment generally associated with the highest bond strength was ethanol.

CLASSIFICATION OF SURFACE FINISH TO BOND NEW TO OLD CONCRETE

This study develops a classification method to understand the relationship between the interfacial bond strength and the surface finish of newly added concrete to old. An experimental program is developed to evaluate the interfacial bond strength between new and old concrete with a various degree of surface finishes. Water jet technology is used to treat the finished surface of the old concrete. The degree of surface finish is determined by the exposure time and the number of repetitions under constant pressure. Each surface finish is analyzed by a 3D scanner focusing on indentation. A sufficient number of images is obtained to develop the classification scheme. The interfacial bonding strength is obtained by testing standard three point bending specimens with two prefabricated interfacial cracks. These specimens are tested to failure in a Mode I fracture only. The results indicate that bonding is improved with the degree of finish up to a peak value that is the optimal finish. Also, the study shows that the strain energy release rate for each surface finish remains to be constant and independent of the of the initial crack length.

An In Vitro Study on the Shear Bond Strength of Feldspathic Porcelain to Nickel Chromium Alloy and Cobalt Chromium Alloy after Various Surface Treatments.

Background To evaluate and compare the shear bond strength of feldspathic porcelain to four distinctively surface-treated Ni-Cr and Co-Cr alloys and to assess the impact of oxidation-heat treatment on porcelain to base metal alloy bond strength. Methods 40 specimens each of nickel-chromium alloy and cobalt-chromium alloy were cast. A total of four groups of specimens were created. Group I was surface-treated by sandblasting with 50 μm alumina particles, Group II was surface-treated by sandblasting with 110 μm alumina particles, Group III and Group IV were surface-treated with 250 μm alumina particles. In Group IV, after sandblasting initially with 250 μm alumina particles, the alloys were subjected to oxidation and resandblasting with 250 μm alumina particles. Each of the specimen was coated with opaque and body porcelain and fired to a total thickness of 2 mm porcelain. A universal measuring machine was used to assess shear bond strength at a crosshead speed of 0.5 mm/min. Results Two-way ANOVA followed by Tukey's post hoc test was used to assess the significant difference within the groups. Unpaired t-test was used for the intergroup comparison of the obtained data. The study showed that the size of the air abrasion particles used for sandblasting significantly influenced the porcelain to metal surface bond strength, with p value <0.001. The bond strength values of the two alloys tested showed no major variations. Result also showed that oxidation influences the metal-ceramic bond strength. Conclusions The bond strength of the metal-ceramic interface is influenced by the alloy's surface treatment. The oxidation process impacts the bond strength of the metal-ceramic system.

Mechanical characterisation of laminated composite AISI 430/304 stainless steels with 1050 Al alloy interlayer

ABSTRACT In this study, multilayered metal composites of austenitic stainless steel (AISI 304) / aluminum alloy (AA 1050) / ferritic stainless steel (AISI 430) are investigated in rolled and heat-treated (350˚C for 24 h) forms comparatively. SEM analysis, tensile test, peel test, bending test, and Vickers microhardness measurement were applied to reveal the microstructural characterisation and mechanical properties of composites. The presence of Fe2Al5 and Fe4Al13 phases are detected in the microstructure investigations, however, significantly thick intermetallic phases were not observed at the interfaces of the laminates. Tensile test results show no significant change in strength despite the increase in ductility after heat treatment. The highest strength of 329.4 MPa and the highest elongation of 26.1% is obtained from the heat-treated condition. The highest interface bond strength is observed at AA1050 / AISI 430 interface after heat treatment. No separation is observed between the layers after bending to a 60˚ angle. A decrease is observed in the hardness values of all layers with the heat treatment. Thus, it has been demonstrated how significant the heat treatment temperature and time, as well as the rolling temperature, are for better interface interaction and mechanical properties for layered composites.

Biodegradable wood plastic composites with phase change microcapsules of honeycomb-BN-layer for photothermal energy conversion and storage

A novel thermal energy storage (TES) composites system consisting of the microPCMs based on n-octadecane nucleus and SiO2/honeycomb-structure BN layer-by-layer shell as energy storage materials, and wood powder/Poly (butyleneadipate-co-terephthalate) (PBAT) as the matrix, was created with the goal of improving the heat transmission and photothermal responsiveness of building materials. The microPCMs were made via mini-emulsion interfacial polycondensation and electrostatic self-assembly to anchor BN on the surface of the SiO2 shell. The two kinds of microPCMs we designed had regular spherical morphology, BN was successfully anchored outside the SiO2 shell, showing a honeycomb structure and good heat storage performance (140.4 J/g and 140.6 J/g). The thermal energy storage wood plastic composites (TES WPCs) had considerable energy storage capacity and temperature regulation ability. The TES WPCs with the unique honeycomb structure of BN-MicroPCMs (BN-WPC) had better heat transfer performance and photothermal conversion efficiency (69.54%), and the thermal conductivity, specific heat capacity and energy storage efficiency of which were increased by 75.06%, 87.06% and 200% respectively. Meanwhile, the unique honeycomb structure strengthened the interfacial bond strength of TES WPCs and brought satisfactory mechanical strength, and the tensile strength, elongation at break, bending strength and bending modulus of BN-WPC are increased by 51.16%, 97.01%, 81.28% and 742.74%, respectively compared with the WPC added with S-MicroPCMs (S-WPC). These results indicated that this research by designing the BN honeycomb structure layer on the traditional microPCMs surface, obtained the rapid thermal response of high-performance TES WPCs in residential construction, thermal energy storage, solar energy collection system and thermal regulation has broad application prospects.

Static bond performance between BFRP bars and concrete with stirrup confinement: A refined modelling

Determining the bond performance between fiber-reinforced polymer (FRP) bars and concrete has been one of the crucial issue for effective application of FRP bars in concrete structures. This study adopted a refined numerical method to investigate the pull-out behavior of embedded basalt FRP (BFRP) bars in concrete with or without BFRP stirrup confinement. In the numerical model, the inherent heterogeneous nature of concrete and surface profiles of the main deformed BFRP bar were explicitly expressed, where the concrete-bar interface was represented using a surface-to-surface contact strategy. The numerical model was calibrated by test results in available literatures and then utilized to conduct a parametric analysis on the bond behavior of BFRP bar-concrete interface. The investigated parameters included thickness-to-diameter ratio (c/d), stirrup ratio, and embedment length. The effect of these parameters on the failure modes, bond stress-slip response, and bond strength were discussed. It was found that the stirrup confinement can change the failure mode from brittle splitting to ductile pull-out and improve the interfacial bond strength, for specimens with c/d less than 3.75. However, the improvement in bond strength becomes insignificant after the stirrup ratio exceeds a critical value. Moreover, after c/d beyond 3.75, the application of stirrup has slight influence on the bond properties. Finally, based on the numerical results, considering the confinement effect of BFRP stirrups, a regression-based equation was derived for the bond strength between BFRP bar and concrete with or without stirrup confinement. The reasonability of the proposed equation was verified by the numerical and collected experimental data.

Correlation between Interface Microstructure and Bond Strength of Al6061/Al6061 HIP-Bonded Plates for Fuel Cladding Application

The effects of hot isostatic pressing (HIP) processing parameters on microstructure and bond strength of Al6061/Al6061 plate interfaces were systemically investigated at the micro- and nanoscale. The HIP bonding of the two aluminum plates was performed at four temperatures: 350°C, 400°C, 450°C, and 560°C. The results reveal the formation of micron scaled Mg2Si precipitate and uniform nano scaled Mg2Al2O5 oxide at the interface. The formation of Mg2Al2O5 is closely associated with the fast bulk diffusion of Mg from the Al matrix to the amorphous Al2O3/Al interface and subsequent reaction between Mg and Al2O3. The highest and lowest bond strengths were observed in samples HIP bonded at 450°C and 350°C, respectively.

GEP Tree-Based Prediction Model for Interfacial Bond Strength of Externally Bonded FRP Laminates on Grooves with Concrete Prism.

Reinforced concrete structures are subjected to frequent maintenance and repairs due to steel reinforcement corrosion. Fiber-reinforced polymer (FRP) laminates are widely used for retrofitting beams, columns, joints, and slabs. This study investigated the non-linear capability of artificial intelligence (AI)-based gene expression programming (GEP) modelling to develop a mathematical relationship for estimating the interfacial bond strength (IBS) of FRP laminates on a concrete prism with grooves. The model was based on five input parameters, namely axial stiffness (Eftf), width of FRP plate (bf), concrete compressive strength (fc′), width of groove (bg), and depth of the groove (hg), and IBS was considered the target variable. Ten trials were conducted based on varying genetic parameters, namely the number of chromosomes, head size, and number of genes. The performance of the models was evaluated using the correlation coefficient (R), mean absolute error (MAE), and root mean square error (RMSE). The genetic variation revealed that optimum performance was obtained for 30 chromosomes, 11 head sizes, and 4 genes. The values of R, MAE, and RMSE were observed as 0.967, 0.782 kN, and 1.049 kN for training and 0.961, 1.027 kN, and 1.354 kN. The developed model reflected close agreement between experimental and predicted results. This implies that the developed mathematical equation was reliable in estimating IBS based on the available properties of FRPs. The sensitivity and parametric analysis showed that the axial stiffness and width of FRP are the most influential parameters in contributing to IBS.

Effects of nano-SiO2 coating and induced corrosion of steel fiber on the interfacial bond and tensile properties of ultra-high-performance concrete (UHPC)

In this study, the effects of nano-silica (SiO2) coating and induced corrosion of steel fibers on the interfacial bond and tensile properties of ultra-high-performance concrete (UHPC) were investigated. Two different types of steel fibers were prepared: plain and nano-SiO2-coated. Corrosion was induced in each of these to two different degrees (2% and 5% by weight) using a 3.5% standard sodium chloride (NaCl) solution. The test results indicate that nano-SiO2 coating increases the bond strengths of steel fibers embedded in UHPC by approximately 50%. Furthermore, more scratches and higher hydrate contents were detected on the surface of nano-SiO2 coated steel fibers after pulling out from UHPC. Under tension, the UHPC containing nano-SiO2-coated steel fibers exhibited double the strain energy density, compared to that containing plain steel fibers. Moderately corroded steel fibers resulted in higher interfacial bond strength and energy absorption capacity owing to the increased surface roughness. In addition, the nano-SiO2 coating enhanced the tensile performance of UHPC even under corrosive environments. This enhancement was however diminished by steel fiber corrosion, so that fiber corrosion needs to be carefully controlled when nano-SiO2-coated steel fibers are used for UHPC.

A review on the factors affecting the properties of natural fibre polymer composites

Improved quality natural fibre composites cannot be achieved without considering certain factors such as the degree of uniformity of the fibre, wettability of the fibre, fibre length, fibre volume fraction, type of matrix, interfacial bond strength, fibre orientation, compatibility of the fibre with the resin, processing parameters and manufacturing techniques among others. Their influences on the properties of the composites with typical examples from previous works were highlighted. The exact or approximate volume fractions of specific fibres in specific resins for optimal performance in composites are lacking. Epoxy, low density polyethylene, polystyrene and polyester resins were mostly used as matrix for natural fibre composites. Epoxy resins possess higher tensile and flexural strengths than polyester resins. Significant differences in the tensile strength and Young’s modulus of natural fibre polymer composites were observed with changes in the orientation and length of the fibres particularly when the differences in length are significant. Other relevant issues affecting natural fibre composites were buttressed with the aim of improving the properties of natural fibre polymer composites for advanced applications.

Effects of Polypropylene/Polyamide Matrix Hybridization on the Interfacial Bonding Strength of Press and Injection Hybrid Molded Product Using Continuous Glass Fiber Reinforced Plastic Composites

Effects of Polypropylene/Polyamide Matrix Hybridization on the Interfacial Bonding Strength of Press and Injection Hybrid Molded Product Using Continuous Glass Fiber Reinforced Plastic Composites

Experimental and numerical investigations of interfacial bond in self-compacting concrete-filled steel tubes made with waste steel slag aggregates

New self-compacting concrete (SCC) mixtures were designed to improve the interfacial bond strength in concrete-filled steel tubes (CFST) at 30 days and one year. The proposed SCC mixtures involved the strengthening of bond strength by using waste steel slag aggregates (SSA). A total of thirty-six circular and squared tube specimens with different ratios (0%, 25% and 50%) of SSA as a replacement by weight of coarse and fine aggregates in SCC were initially prepared. The results revealed that the using of SSA in SCC enhanced the specimens' bond strength for both shapes of steel tubes and the bond strength was reduced with an increase of concrete's age. Additionally, the incorporating of SSA did not decrease the loss in bond strength at one year. A three-dimensional non-linear finite element (FE) analysis was further conducted to simulate the interfacial bond-slip mechanism between two surfaces of the infill concrete and inner steel tubes.

Effect of Vibration Acceleration on Interface Microstructure and Bonding Strength of Mg–Al Bimetal Produced by Compound Casting

Vibration was adopted to enhance the interface bonding of Mg–Al bimetal prepared by the lost foam compound casting (LFCC) technique. The Mg–Al bimetallic interface was composed of three layers: layer I (Al3Mg2 and Mg2Si phases), layer II (Al12Mg17 and Mg2Si phases), and layer III (Al12Mg17 + δ-Mg eutectic structure). With the increase in vibration acceleration, the cooling rate of the Mg–Al bimetal increased, resulting in the decrease in the reaction duration that generates the intermetallic compounds (IMCs) layer (including layers I and II) and its thickness. On the other hand, the Mg2Si phase in the IMCs layer was refined, and its distribution became more uniform with the increase in the vibration acceleration. Finally, the shear strength of the Mg–Al bimetal continued to increase to 45.1 MPa when the vibration acceleration increased to 0.9, which was 40% higher than that of the Mg–Al bimetal without vibration.

Optimization of SiC–ZrC high emissivity composite flexible coating for thermal protection with high interfacial bond strength and temperature resistance

Aluminum silicate fiber fabric (ASFF) has been widely used in the outer surface of flexible insulation felt on the leeward side of aerospace vehicle. In order to improve the temperature resistance of ASFF, a kind of SiC–ZrC composite coating was prepared on the surface of fiber fabric via spraying method with SiC as emittance agent and ZrC as additive. The surface morphology and mechanical properties of the coating were studied. Compared with the single-component SiC coating, the composite coating could effectively avoid coating spalling and improve the surface integrity at high temperature. After thermal treatment at 1100 °C for 2 h, the interface bond strength of the composite coating/substrate was 52.41% higher than that of SiC coating/substrate. The tensile strength of fiber fabric with SiC–ZrC composite coating could reach 91.75 MPa, which was 101.76% higher than that of raw ASFF. Therefore, the SiC–ZrC coating could greatly improve the temperature resistance of ASFF, and has an attractive application prospect in the field of thermal protection system.

Study on the interface bond strength of DP780 steel/CFRP composite laminate based on hot-press curing integration

The metal and carbon fiber reinforced plastic (CFRP) hybrid parts are increasingly used in automobile industry to meet the demand for vehicle weight reduction. The interface bond strength between metal and CFRP is the key to the part properties. The effects of different surface treatments on the interface bond strength of DP780 Steel/CFRP composite laminate based on hot-press curing integration were studied. Single lap test and single-leg bending (SLB) test were used to characterize the interface bond strength of the hybrid composite laminate. Interface failure mechanism was analyzed through surface roughness, fracture mode and fracture morphology. The experimental results showed that the steel surface treated by laser exhibited the highest surface roughness and the greatest surface energy in contrast to other surface treatments, such as degreasing, acid corrosion and grinding. The single lap test results showed that the laser-treated specimen had the maximum interface bond strength and there were a lot of fibers residues on the steel fracture surface. In SLB tests, there was no gap between the laser-treated steel and CFRP interface. The interface was bonded finely, which greatly improved the interface bond strength.

The Efficiency of Hybrid Intelligent Models in Predicting Fiber-Reinforced Polymer Concrete Interfacial-Bond Strength

Fiber-reinforced polymer (FRP) has several benefits, in addition to excellent tensile strength and low self-weight, including corrosion resistance, high durability, and easy construction, making it among the most optimum options for concrete structure restoration. The bond behavior of the FRP-concrete (FRPC) interface, on the other hand, is extremely intricate, making the bond strength challenging to estimate. As a result, a robust modeling framework is necessary. In this paper, data-driven hybrid models are developed by combining state-of-the-art population-based algorithms (bald eagle search (BES), dynamic fitness distance balance-manta ray foraging optimization (dFDB-MRFO), RUNge Kutta optimizer (RUN)) and artificial neural networks (ANN) named “BES-ANN”, “dFDB-MRFO -ANN”, and “RUN-ANN” to estimate the FRPC interfacial-bond strength accurately. The efficacy of these models in predicting bond strength is examined using an extensive database of 969 experimental samples. Compared to the BES-ANN and dFDB-MRFO models, the RUN-ANN model better estimates the interfacial-bond strength. In addition, the SHapley Additive Explanations (SHAP) approach is used to help interpret the best model and examine how the features influence the model’s outcome. Among the studied hybrid models, the RUN-ANN algorithm is the most accurate model with the highest coefficient of determination (R2 = 92%), least mean absolute error (0.078), and least coefficient of variation (18.6%). The RUN-ANN algorithm also outperformed mechanics-based models. Based on SHAP and sensitivity analysis method, the FRP bond length and width contribute more to the final prediction results.

Bond formation at polycarbonate | X interfaces (X = Ti, Al, TiAl) probed by X-ray photoelectron spectroscopy and density functional theory molecular dynamics simulations

To investigate the bond formation at polycarbonate (PC) | X interfaces (X = Ti, Al, TiAl) by X-ray photoelectron spectroscopy, thin metallic layers were deposited onto PC substrates by direct current magnetron sputtering. Additionally, changes in the chemical state of the polymer were studied systematically by density functional theory molecular dynamics simulations of a PC dimer interacting with the corresponding metallic surfaces. These predictions were confirmed by experiments, indicating a higher reactivity at PC | Ti interfaces: Ti reacts with all functional groups of PC, forming numerous interfacial CTi and (CO)Ti bonds, whereas Al exhibits selective reactivity as only (CO)Al bonds with the carbonate group are formed. However, integrated crystal orbital Hamilton population (ICOHP) calculations indicate a significantly higher interfacial bond strength for (CO)Al bonds compared to (CO)Ti and CTi bonds (ICOHP differences up to 3.1 eV). By multiplying the experimentally determined relative interfacial bond concentration with the theoretically determined maximum bond strength as an indicator for adhesion, the PC | Ti interface exhibits a ∼1.9 and ∼1.4 times larger value compared to the PC | Al and the PC | TiAl interface, respectively. Thus, Ti thin films are the preferential choice as adhesion layers for PC.

Consideration of a Tack Coat Bond Strength Test to Minimize the Potential for Slippage Failures on Flexible Airfield Pavements

Slippage failures on flexible pavements are a potential problem for airports given the large wheel loads and high tire pressures of modern aircraft. While not common, when slippage failures do occur the impact can be significant on flexible pavement performance. This paper has three components: (1) case studies of slippage failures that have occurred on airfield pavements; (2) a literature review of relevant interlayer bond strength test procedures; and (3) the results of an analytical, field, and laboratory research investigation. Component (3) was conducted to assess the suitability of interface bond strength tests to evaluate the sufficiency of interlayer bond strength between lifts of asphalt pavement, either new construction or an overlay of existing pavement. The analytical study found that for a fully bonded pavement (no-slip condition), subgrade strength was the primary factor affecting horizontal stress at the interface followed by wheel load. Field cores were obtained from recently constructed asphalt pavements and brought to the laboratory for monotonic direct shear testing to determine bond strength as well as monotonic indirect tensile testing to determine mixture strength. Testing was conducted at 77°F (25°C) and 136°F (58°C). Results showed better repeatability at room temperature with similar relative performance ranking to the critical case high temperature test. Bond strength was influenced by in-place mixture density. Overall, the bond strength test method was practicable for use in field laboratories for acceptance testing.

Experimental Study of the Factors Influencing the Performance of the Bonding Interface between Epoxy Asphalt Concrete Pavement and a Steel Bridge Deck

The bonding between pavement and a steel bridge deck is a key component affecting the structural integrity of steel deck pavement and delamination is a major cause. The bonding interface of steel deck pavement was systematically investigated to evaluate the interactive influences of factors, such as the air void of the asphalt concrete pavement, the surface roughness of the steel deck, the thickness of the zinc-rich epoxy primer, and the waterproof bonding membrane, on the bond strength of the pavement interface, through simulated loading, brine immersion, pull-off, and interface observation experiments. The results show that a low air void (&lt;3.0%) was a necessary condition for the corrosion resistance and bonding reliability of the steel deck pavement structure, and a zinc-rich epoxy primer provided an additional guarantee for corrosion resistance of the steel deck pavement; additionally, the combination of steel deck plate roughness in the range of 120–140 μm and zinc-rich epoxy primer thickness in the range of 80–110 μm led to a high bond strength, which was also conducive to the corrosion resistance of the steel bridge plate. The steel deck pavement structure should be designed through combinatorial optimization of multiple factors to create an integrated waterproof and anticorrosion bonding system.

Push-out tests of CFST columns strengthened with self-compacting and self-stressing concrete filled square steel tube

There are two dominant interfaces in concrete-filled steel tube (CFST) columns strengthened with CFST jacketing: (a) interface between the sandwiched concrete and the outer wall of the inner steel tube (interface Ti); (b) interface between the sandwiched concrete and the inner wall of the outer steel tube (interface To). 16 push-out tests were conducted on CFST columns strengthened with self-compacting and self-stressing concrete filled square steel tube to study the bond behaviour of the two interfaces. The experimental parameters included the sandwiched concrete strength (C50, C60 and C70), thickness of outer steel tube (3.5, 4.5 and 5.5 mm), self-stressing (with and without) and interface type (interface Ti and interface To). The influence of different parameters on the bond behaviour was assessed and the longitudinal strain distribution of interfaces To and Ti along the length of the outer and inner steel tubes was analyzed, respectively. The results indicate that the interfacial bond stress presents as an exponential function in the direction of interface length. Interface Ti has higher average ultimate bond strength compared with corresponding interface To. The bond strengths of both interfaces increase with increasing sandwiched concrete strength and thickness of outer steel tube. However, the self-stressing only has evident effect on the bond strength of interface To. In addition, formulas for calculating the bond strengths of both interfaces in retrofitted columns were proposed, and the experimental results from previous studies were also compared with predictions from proposed formulas and design codes.