Average Bond Strength Research Articles

Combined corrosion and inclination effects on pullout behavior of various steel fibers under wet-dry cycle deterioration

The interfacial bond behavior of corroded fibers in cracked steel fiber reinforced concrete (SFRC) is critical for understanding its structural deterioration performance, while available research focused on aligned straight or hooked-end fibers. This study investigated the combined effects of corrosion and inclination on the pullout performance of various steel fibers bridging artificial cracks exposed to wet-dry cycles of chlorides. Three deformed steel fibers, i.e., hooked-end (H), crimped (C), and milled-cut (M) fibers, with three angles of 0°, 30°, and 45° were examined under both uncorroded and corroded conditions. After corrosion, the average bond strength of H fibers was enhanced due to increased roughness and compact rust layer if the high inclination-induced fracture was avoided, while that of C and M fibers was decreased at various angles because of loose and porous rusts. The highest bond strengths of corroded H, C, and M fibers were discovered at 30°, 30°, and 0°, as a result of the combined mechanisms of snubbing effect, matrix spalling, or corrosion-induced fracture. The ultimate displacement of all fibers increased with angles due to increased matrix spalling area and fiber plastic deformation. The inclination effect of corroded fibers was more significant on energy absorption capacity than average bond strength, regardless of fiber type. A degradation model that describes the snubbing and matrix spalling effects, as well as the corrosion-induced deterioration and fracture was developed, based on which the critical inclination angle was found to decrease with increasing embedded length and decreasing tensile strength.

Experimental study of interfacial adhesion performance of prefabricated UHPC-NC diagonal shear groove

The reinforced lining of the tunnel was carried out using a prefabricated composite structure consisting of Ultra-High Performance Concrete (UHPC) and Normal Concrete (NC), utilizing a semi-post-pouring method. The bond performance between UHPC and NC is crucial for enhancing the overall stability and safety of the tunnel. To investigate the influence of interface construction on the bond performance at the UHPC-NC interface, inclined shear tests were conducted with variations in groove density, groove morphology, groove aspect ratio, and interface angle. The results revealed four different failure modes of the grooved specimens, with over 80% exhibiting failure at the interface between UHPC and NC. The average interface bond strength of the grooved specimens was found to be 5.8 times higher than that of the untreated interface group, indicating a significant improvement in the bond performance of the UHPC-NC interface due to the presence of grooves. When the volume loss ratio was below 0.09, the interface bond strength of the UHPC-NC interface increased with an increase in groove density. The interface bond strength of the 60° trapezoidal grooves was 80% higher than that of the right-angle grooves, while the interface bond strength of the 40° trapezoidal grooves was 28% higher than that of the right-angle grooves. Furthermore, the interface bond strength decreased as the angle between the interface and the horizontal plane increased. The precast inclined shear grooves exhibited a bond-slip curve that consisted of an initial slow-rise stage, an elastic rise stage, a yield stage, and a failure descent stage, with some specimens not exhibiting a distinct yield stage. In this study, a bond-slip model for the precast UHPC-NC inclined shear grooves was proposed, and recommendations for bond stiffness were provided.

Investigation on bond durability of GFRP bar/engineered cementitious composite under alkaline-saline environments

Integration of GFRP bars and Engineered Cementitious Composites (ECC) as construction materials for a structure could significantly improve its long-term durability against harsh environments, while maintaining high loading bearing capacity, striving for overcoming corrosion-induced cracking and premature failure existed in conventional steel reinforced concrete structures. Although significant research has been conducted on the bond durability between GFRP bars and various types of concrete, very few studies specifically addressing the bond durability between GFRP bars and ECC could be found in the literature and their damage mechanisms are not clear, especially from the perspectives of multi-factorial consideration at both the micro and macro levels. As a result, the conclusions drawn from the existing studies cannot be entirely applied to these two materials. Hence, this research investigates the impact of alkaline-saline environments on the interfacial bond properties of GFRP bars embedded in ECC from macro and micro perspectives. To examine the degradation of bond properties under the effect of different factors, a total of 45 pullout specimens were prepared. The experimental variables included different immersion durations (0, 30, 60, and 90 days), surface treatments of GFRP bars, concrete types, and matrix compressive strengths. The specimens were subjected to accelerated aging tests with increased concentration of the alkaline-saline solution before conducting pullout tests. The analysis of bond degradation included the assessment of weight loss, failure mode, bond mechanism, bond stress, Scanning Electron Microscopy (SEM) imaging, and specimen composition. The results demonstrated that failure modes were highly dependent on concrete types and bond mechanisms. Untreated bar specimens exhibited higher bond strength when combined with ECC, while ribbed bar specimens showed little difference in peak strength between E30 and N30 specimens. The bond strength of ribbed bar/ECC specimens decreased by 5.88% and 8.55%, respectively, after 60 days and 90 days immersion, compared with that of the specimens without immersion. Furthermore, an improvement in the compressive strength of ECC resulted in enhanced bond strength. Specifically, the average bond strength of E50 specimens increased by approximately 14.5% compared to E30 specimens after 60 days of immersion. SEM analysis revealed an increase in calcium silicate hydrate gel (C–S–H) at the ECC interface after immersion, as NaOH and NaCl solutions penetrated the concrete and bond interface. The bond-slip relationships of the specimens were affected by immersion durations. The matrix-added fibers increased the ductility of specimens, providing benefits in the residual stage. The bond-slip curves were fitted with the mature models, and mBPE model demonstrated a strong agreement with the ascending and descending branches. Lastly, referring to fib Bulletin 40, the bond strength retention of ribbed bar/E30 specimens was predicted to be 69.05% and 67.25% after 50 and 100 years of expected service life, respectively.

The microstructure and mechanical properties of cementless ultra-high-performance alkali activated concrete considering geometrical properties of steel fiber

This study investigates the impact of steel fiber geometrical properties on the interfacial bond and tensile behavior of ultra-high-performance alkali activated concrete (UHP-AAC). Two types of steel fibers, straight and hooked-end, with aspect ratios of 65, 97.5, and 125 were examined. Results showed that the hooked-end steel fiber exhibited the highest average and equivalent bond strengths in the UHP-AAC matrix, measuring 15.13 and 11.46 MPa, respectively, which were approximately 66% and 94% higher than those of straight steel fibers in the same matrix and bonding area. The best tensile performance of UHP-AAC was achieved using straight steel fibers with an aspect ratio of 97.5, demonstrating the highest tensile strength and strain energy density of 12.28 MPa and 55.24 kJ/m3, respectively, and the second highest strain capacity of 0.533%. Straight steel fibers were more effective in increasing the tensile strength of UHP-AAC than hooked-end steel fibers with the same aspect ratio. Higher fiber aspect ratios resulted in larger microcrack widths, with the straightened end-hooks acting on the crack plane to transmit tensile force more effectively, contributing to increased microcrack width and deformability.

In vitro Evaluation of Shear Bond Strength of Orthodontic Brackets Bonded with Different Adhesives.

To endure the orthodontic forces used throughout treatment, the bond strength of bonded orthodontic brackets must be enough with assessment of shear bond strength when bonding orthodontic brackets with various adhesives. Overall, forty extracted premolars due to orthodontic treatment were included. They were split into four equal cohorts with various primers. With both adhesives, shear bond strength had been assessed with and without salivary contamination. SPSS software was used to assess the outcomes. Consideration was given to statistical significance of P value of less than 0.05. Several groups' average bond strengths in MPa were assessed in both dry and contaminated saliva conditions. When it was dry, Transbond Plus demonstrated greater shear bond strength. Hydrophilic Transbond Plus resin outperformed hydrophobic Transbond XT resin in terms of shear bond strength under both situations.

Experimental Study on the Bonding Performance between Fiber-Belt-Bar and Concrete

Fiber materials have advantages such as light weight and high strength, corrosion resistance, fatigue resistance, and easy processing and production, and they are widely applied in the repair and renovation of concrete structures. To promote the construction convenience of fiber materials, fiber raw yarn is continuously braided to form fiber-belt-bars. Based on the existing research, the performance of bonding between fiber-belt-bars and a concrete interface was investigated, and pull-out tests were performed to systematically investigate the effects of the fiber-belt-bar cross-sectional size, anchorage length, concrete strength, and fiber type on the bonding performance. The experimental results show that the bond strength reduces with an increase in the anchorage length, increase in cross-sectional size, and decrease in concrete strength, and the effect of fiber type on the bond strength is not obvious. On this basis, a formula for calculating the average bond strength of fiber-belt-bars is proposed. Experiments and calculations determined that the average bond strength between fiber-belt-bar and concrete with a cross-sectional size of 12 mm × 3 mm is 10–30% higher than that with a cross-sectional size of 20 mm × 3 mm for the same anchorage length. Finally, the minimum anchorage length of the fiber-belt-bar is proposed to provide a valuable reference for the use of fiber-belt-bar in concrete projects.

Valence electron concentration- and N vacancy-induced elasticity in cubic early transition metal nitrides

Motivated by frequently reported deviations from stoichiometry in cubic transition metal nitride (TMNx) thin films, the effect of N-vacancy concentration on the elastic properties of cubic TiNx, ZrNx, VNx, NbNx, and MoNx (0.72≤x≤1.00) is systematically studied by density functional theory (DFT) calculations. The predictions are validated experimentally for VNx (0.77≤x≤0.97). The DFT results indicate that the elastic behavior of the TMNx depends on both the N-vacancy concentration and the valence electron concentration (VEC) of the transition metal: While TiNx and ZrNx exhibit vacancy-induced reductions in elastic modulus, VNx and NbNx show an increase. These trends can be rationalized by considering vacancy-induced changes in elastic anisotropy and bonding. While introduction of N-vacancies in TiNx results in a significant reduction of elastic modulus along all directions and a lower average bond strength of Ti–N, the vacancy-induced reduction in [001] direction of VNx is overcompensated by the higher stiffness along [011] and [111] directions, resulting in a higher average bond strength of V–N. To validate the predicted vacancy-induced changes in elasticity experimentally, close-to-single-crystal VNx (0.77≤x≤0.97) are grown on MgO(001) substrates. As the N-content is reduced, the relaxed lattice parameter a0, as probed by X-ray diffraction, decreases from 4.128 Å to 4.096 Å. This reduction in lattice parameter is accompanied by an anomalous 11% increase in elastic modulus, as determined by nanoindentation. As the experimental data agree with the predictions, the elasticity enhancement in VNx upon N-vacancy formation can be understood based on the concomitant changes in elastic anisotropy and bonding.

Effects of the tensile properties of UHPC on the bond behavior

In recent studies, Ultra-high Performance Concretes (UHPC) have been shown to exhibit significantly better bond with steel reinforcement compared to conventional concrete. However, the influence of the fundamental tensile properties of UHPC on the bond behavior has not been evaluated. The present study addresses this knowledge gap by investigating the bond behaviors of three UHPC materials. Two of these materials exhibit typical UHPC behavior with different tensile strengths, and the third material is a highly ductile UHPC with tensile strain capacity of about 6.6%. Through double-pullout experiments, it was found that higher tensile strength of UHPC led to a significant improvement in the average bond strength (τav); however, the tensile strain capacity did not have any significant effect on τav. The τav increased by about 50 to 64% for various materials with increase in the cover thickness from 1.5d to 2.5d due to better confinement. On the other hand, τav decreased by approximately 34% with increase in the embedment length from 3d to 8d with a cover thickness of 1.5d, and it decreased by about 40% with increase in embedment length from 2d to 6d with a cover thickness of 2.5d. The experiments were complemented with finite element analyses, which provided key insights into the bond stress distribution in embedded rebars.

Role of ordered carbon vacancies on stability and mechanical properties of VC1−X in bainite steel by first-principles calculations and experimental characterization

There has been little systematic research into vanadium carbides (VC1−X) configuration in bainite steel. Structural stability, mechanical properties, and thermal properties among vast VC1−X configurations for 20MnSiCrV bainite steel were studied here using first-principles calculations and experiments. The calculated results predicted stable and metastable VC1−X structures, and their intrinsic elasticity and hardness were related to carbon vacancy concentration varies, following parabolic law. A decrease in average bond strength and the number of V-C covalent bonds caused by fewer carbon atoms will lead to VC1−X softening. The calculated values for mechanical properties are in excellent agreement with existed available experimental data. Moreover, lattice thermal conductivity of VC1−X is not only dependent on carbon vacancy contents but also related to compound configuration. Furthermore, the calculated stable structures of VC (Fm3¯m), V8C7 (P4332), and V2C (Pbcn) are verified by TEM (Transmission Electron Microscope) observation. These results of VC1−X structural stability and properties provide a guideline to study vanadium second phases in bainite steel and ensure the subsequent extended research of vanadium microalloying in steel.

Bond strength between reinforcement and High Volume Fly Ash-Self Compacting Concrete (HVFA-SCC)

This paper explains the bond strength between the reinforcing bar and High Volume Fly Ash-Self Compacting Concrete (HVFA-SCC). The bond strength is determined by a pull-out test on the concrete cube (200x200x200 mm) with a single steel bar centrally placed in the cube following the RILEM standard. The HVFA-SCC is proportioned with an inclusion of 50% fly ash by weight of the total binder. The concrete satisfies the flowability criteria of SCC and has the average concrete compressive strength of 38.8 MPa. The test result shows that an average bond strength of HVFA-SCC is 12.93 Mpa and 3.89 MPa for deformed and plain bars, respectively. The obtained bond strength of HVFA-SCC is compared with the bond strength of other concrete types found in the literature. It confirms that the HVFA-SCC bond strength is higher than normal concrete (NC), and comparable with geopolymer concrete (GC), HVFAC, and SCC.

A Comparison of the Shear Bond Strength of Orthodontic Brackets Bonded With Different Orthodontic Adhesives.

The purpose of this study was to examine the strength of the bonding between orthodontic brackets and different orthodontic adhesives. To achieve this, the researchers selected 120 extracted premolars and divided them into four groups randomly. Then, one of the three adhesives, Transbond XT, Bracepaste, or Heliosit, was used to join the brackets together. After bonding, the force needed to remove the brackets was tested, and the amount of adhesive that remained on the tooth surface was also noted (referred to as the adhesive remnant index or ARI). The results showed that Transbond XT had an average bond strength of 18.05 ± 5.6 MPa, Bracepaste had an average bond strength of 16.6 ± 5.1 MPa, and Heliosit had an average bond strength of 16.2 ± 4 MPa. The average bond strength and ARI scores for Transbond XT and Bracepaste were similar at 11.10 MPa. The study found that the light-cured composite adhesives provided the strongest bond and left the tooth surface smoother and cleaner. In conclusion, the study presented significant information about the impact on the enamel surface as well as the strength of the bond between orthodontic brackets and different adhesives.

Bond performance of CFRP bars embedded in UHPFRC incorporating orientation and content of steel fibers

The bond behavior of carbon fiber-reinforced polymer (CFRP) bars embedded in ultra-high-performance fiber-reinforced concrete (UHPFRC) is a pivotal factor affecting the performance of CFRP bar-reinforced UHPFRC structures. The present investigation delves into the bond performance of CFRP bars in UHPFRC by conducting tests on thirty-six pullout specimens. In these tests, the effects of steel fiber orientation, steel fiber content, and CFRP bar diameter were considered. The results revealed that specimens with 12 mm-diameter CFRP bars primarily failed in a splitting-pullout mode, whereas those with 10 mm- and 8 mm-diameter CFRP bars exhibited pullout failure. It was observed that specimens containing 45° oriented steel fibers have the maximum bond strength (∼35.30 MPa), as the cracks within UHPFRC were more effectively constrained. The bond strength was found to increase with an increase in steel fiber content, attributed to the improved cracking resistance of UHPFRC. The average bond strengths of specimens with fiber contents of 2% and 2.5% are respectively increased by 10.66% and 14.52% compared to those with a fiber content of 1.5%. The bond strength increases with the increase in CFRP bar diameter, owing to the greater rib height and rib height-to-inner diameter ratio of larger-diameter CFRP bars. Finally, a theoretical model was developed to predict the bond strength, with an average ratio of predicted results to experimental results of 0.93 and a standard deviation of 0.176.

Effect of chloride-induced corrosion on bond performance of various steel fibers in cracked SFRC

This study investigates the chloride-induced corrosion behavior of various steel fibers and associated effects on their interfacial bond performance in cracked steel fiber reinforced concrete (SFRC). Three types of deformed fibers, including hooked-end (H), crimped (C), and milled-cut (M) fibers, were embedded in high strength matrix and then exposed to wet-dry cycles of chlorides under cracking conditions. The scanning electron microscope (SEM) and energy-dispersive X-ray (EDX) technique were employed to gain insights into the surface morphologies and corrosion products at the micro-scale. The bond behaviors of corroded fibers were further evaluated through pull-out tests, where the influences of fiber type, corrosion duration, crack width, and embedded length were discussed. Three distinct corrosion morphologies were identified on the surfaces of three types of fibers owing to the difference in corrosion products. After 40 days of corrosion, the average bond strength of H fibers increased by 37.9% because of dense and rough rust layer, while those of C and M fibers deteriorated by 30.5% and 18.8% due to surficial groove loss and loose rust layer. The average bond strength of H, C, and M fibers improved by 12.4%, 11.7%, and 58.0% as the crack width increased from 0.1 to 0.3 mm, whereas significant reductions in pull-out energy and equivalent bond strength were obtained once the crack width exceeded 0.2 mm owing to fiber fracture. The corrosion-induced bond deterioration of M fibers became less severe as the embedded length increased up to 12 mm and remained unaffected thereafter.

Experimental Study on the Bonding Performance of HIRA-Type Material Anchor Solids Considering Time Variation

In order to reveal the evolution of bonding performance of HIRA (High Intensity and Rapid Agent) anchor solids with maintenance time, the evolution characteristics of bond strength and stress distribution at the interface between HIRA-based anchor solids and a geotechnical body under different maintenance times and the fine damage pattern of anchor solids were studied by an indoor pull-out test of anchor solids. The comparative analysis was performed with 42.5 grade ordinary Portland cement (hereinafter referred to as P.O 42.5). The results show that the early strength and rapid setting characteristics of HIRA type material are obvious, and the difference between its average peak bond strength and that of cement is 10.45 times. The shear stress distribution has obvious stress concentration characteristics, and the peak value will appear and shift with the increase in load, and the peak shift of the HIRA anchor solid occurs earlier than that of cement. Due to different stress levels, the damage of the HIRA anchor solid after being pulled out increases with the increase in maintenance time, while that of cement gradually becomes more severe. The overall damage of the HIRA material is generally lower than that of cement in the same period.

Modulating Optoelectronic and Elastic Properties of Anatase TiO2 for Photoelectrochemical Water Splitting

Titanium dioxide (TiO2) has been investigated for solar-energy-driven photoelectrical water splitting due to its suitable band gap, abundance, cost savings, environmental friendliness, and chemical stability. However, its poor conductivity, weak light absorption, and large indirect bandgap (3.2 eV) has limited its application in water splitting. In this study, we precisely targeted these limitations using first-principle techniques. TiO2 only absorbs near-ultraviolet radiation; therefore, the substitution (2.1%) of Ag, Fe, and Co in TiO2 significantly altered its physical properties and shifted the bandgap from the ultraviolet to the visible region. Cobalt (Co) substitution in TiO2 resulted in high absorption and photoconductivity and a low bandgap energy suitable for the reduction in water without the need for external energy. The calculated elastic properties of Co-doped TiO2 indicate the ductile nature of the material with a strong average bond strength. Co-doped TiO2 exhibited fewer microcracks with a mechanically stable composition.

Experimental Study on the Bond Performance of Steel–Basalt Fiber Composite Bars in Concrete

Steel–basalt fiber composite bars (SBFCBs) exhibit excellent strength, elastic modulus, toughness, corrosion resistance, and low cost. Understanding the bond performance between SBFCBs and concrete is important for evaluating the mechanical behavior of SBFCB-reinforced concrete structures. In this study, the bond–slip performance of SBFCB in concrete was experimentally assessed via pullout and beam bond tests. The influence of various factors on the bond performance was discussed, and the bond mechanism between SBFCB and concrete was analyzed. The results indicate that reducing the thread pitch ratio in the SBFCB can reduce slippage at the postpeak bonding stress–slip curve. The bond strength of the SBFCB was significantly improved by sandblasting. Longer bond lengths correspond to smaller average bond strengths in SBFCB. The load corresponding to the maximum bond strength of a specimen with a bond length of 10d was determined as the ultimate load value for the SBFCB. An increase in the SBFCB diameter had a negative impact on the bond strength. Moreover, an increase in the concrete cover thickness was conducive to improving the bond strength; if the thickness of the concrete cover was sufficiently increased, failure occurred owing to SBFCB tension rather than bonding. Based on the test results and the existing bond–slip model, a simple bond–slip constitutive model of the SBFCB embedded in concrete was proposed to simulate the pullout process of the SBFCB. Subsequently, the established bond–slip model can be used to analyze the mechanical performance of SBFCB-reinforced concrete structures.

Optimization of fiber aspect ratio for 90 MPa strain-hardening geopolymer composites (SHGC) with a tensile strain capacity over 7.5%

This study developed high-strength strain-hardening geopolymer composites (SHGC) containing 2% (by volume) polyethylene (PE) fibers. A high-strength geopolymer matrix with a compressive strength of over 100 MPa was achieved using liquid crystal display glass powder and ground granulated blast furnace slag. To determine the optimum aspect ratio of PE fibers, five different types of PE fibers with aspect ratios ranging from 300 to 900 were considered. The average bond strength of PE fibers in the high-strength geopolymer matrix was 1.55 MPa, similar to that of high-strength cement matrices. The PE fibers with higher aspect ratios were more effective for improving the tensile performance of high-strength SHGC than those with lower aspect ratios, and a robust strain-hardening characteristic with saturated micro-crack patterns was obtained when the fiber aspect ratio exceeded 600. The energy-based pseudo strain-hardening index (Jb′/Jtip) was found to be 25.3 at a fiber aspect ratio of 600, and it increased to 104.3 with the increase in the fiber aspect ratio up to 900. The best tensile performance—tensile strength of 5.73 MPa, strain capacity of 7.58%, and strain energy density of 309.6 kJ/m3—was achieved in the high-strength SHGC reinforced with PE fibers having an aspect ratio of 900.

The influence of wood surface treatments with different biomolecules on dry and wet strength of linear friction welded joints

The moisture resistance of friction-welded wood joints can be improved by applying bio-based bonding additives. Several biomolecules including tannic acid, organosolv lignin from hardwood, kraft lignin from softwood, and derivates thereof, were investigated regarding their applicability as bonding additives in the friction welding process. Welding with kraft lignin showed significantly increased moisture stability after 24 h water immersion. An average wet bond strength of 1.5 MPa compared to 0.38 MPa of untreated spruce was obtained. Modification of kraft lignin through succinylation, acetylation or depolymerisation led to no further improvement in moisture stability. Depolymerised kraft lignin resulted in an even higher delamination rate of the samples during water immersion than untreated samples. Structural analysis of the lignin variations by FTIR-ATR, GPC and 31P NMR in combination with thermal analysis by TGA and DSC showed the impact of various structural and chemical features on the thermal behaviour and intermolecular interactions of the applied lignin.

Effects of Ga on the structural, mechanical and electronic properties of β-Ti-45Nb alloy by experiments and ab initio calculations

This work aims to investigate the structural, mechanical and electronic properties of four novel β-type (100-x)(Ti–45Nb)-xGa alloys (x = 2, 4, 6, 8 wt%) for implant applications by means of experimental and theoretical (ab initio) methods. All alloys retain the bcc β phase in the solution-treated and quenched state while the lattice parameter decreases with increase in Ga content. This is due to its smaller atomic radius compared to Ti and Nb, in line with the present density functional theory (DFT) calculations. Tensile and microhardness tests indicate a clear strengthening effect with increasing Ga content, with yield strengths in the range 551 ÷ 681 MPa and microhardness in the range 174 ÷ 232 HV0.1, mainly attributed to grain refinement and solid solution strengthening. Ga also positively affects ductility, with a maximum value of tensile strain at fracture of 32%. Non-destructive ultrasonic measurements and DFT calculations reveal that the bulk modulus is unaffected by the Ga presence. This phenomenon might be due to the fact that Ga introduced bonding and anti-bonding electron low energy states which balance the average bond strength among the atoms in the metallic matrix. Nevertheless, the introduction of new Ga–Ti super sp-like bonding orbitals along the [110] and [−110] directions in the Ga neighborhood could explain the increase of the Young's modulus upon Ga addition (73 ÷ 82.5 GPa) that was found experimentally in the present work. Hence, Ga addition to Ti–45Nb leads to a suitable balance between increased strength and low Young's modulus.

Experimental study and analysis of the bond-anchorage properties of laminated flattened-bamboo lumber connections with glued-in steel rod

To improve the utilization rate of raw bamboo and reduce the amount of adhesive, this paper studied a new type of laminated bamboo lumber, that is, laminated flattened bamboo lumber. The monotonic pull-out tests were carried out on 56 specimens with glued-in steel rods of three different diameters (12 mm, 16 mm, and 20 mm, respectively; the thickness of the adhesive layer was 3 mm) of laminated flattened bamboo lumber, and the effect of anchorage length and diameter of the steel bar on the mechanical properties of bond anchorage were studied. In addition, the specimens with a diameter of 12 mm and an anchorage length of 100 mm were selected to study the effect of different thicknesses of the adhesive layer (between 2 mm and 4 mm) on the mechanical properties of bonded anchorage. The results showed that the failure modes could be divided into three types. For the specimens with the same anchorage length, the larger the diameter of the glued-in steel bar was, the larger the ultimate pullout load would be; when the diameter of the steel bar was the same, the ultimate pullout load of the specimens increased with the increase of the anchorage length. When the diameter of the glued-in steel bar was 12 mm, the average bond strength decreased with the increase in slenderness ratio. When the diameter of the glued-in steel bar was 16 mm and 20 mm, the average bond strength first increased and then decreased with the increase of the slenderness ratio, and the turning slenderness ratio points were 8.75 and 5, respectively. The ANOVA analysis with parameters revealed that the rebar’s diameter and length significantly impacted the bond-anchorage characteristics of the glued-in rod connection in laminated flattened bamboo lumber.