Effect Of Reinforcement Research Articles

Mechanical properties and ductility improvement mechanisms of fiber-reinforced biomimetic mineralized composites using sea sand

Biomimetic mineralized composites (BMC) is an emerging green cementing material. However, the application of BMC is limited by brittle failure. This study proposes novel fiber-reinforced biomimetic mineralized composites (FRBMC) with excellent ductility based on the coupling method of fiber reinforcement and biomimetic chemically induced calcium carbonate precipitation (BCICP). Three typical fibers, including polymer fibers (polypropylene fiber, PF), mineral fibers (basalt fiber, BF), and plant fibers (coir fiber, CF), were used to explore the feasibility of application in FRBMC. Accordingly, mechanical properties, pore structures, and microscopic characteristics were assessed through unconfined compressive strength (UCS) test, mercury intrusion porosimetry (MIP) tests, and scanning electron microscopy (SEM). The results show that fiber induces a transition from brittle to ductile failure modes in BMC. PF exhibits the most notable enhancement in residual strength and peak strain, while BF leads to the highest compressive strength. CF can effectively enhance energy absorption after reaching peak stress. Moreover, FRBMC with CF contains a higher quantity of minute pores, while BF can reduce the porosity of FRBMC. The calcium carbonate crystals effectively cement fibers and sand particles, enhancing the ductility of FRBMC through forming various cementing structures. This study investigates the synergistic effect of BCICP and fiber reinforcement, providing valuable guidance for potential practical applications of FRBMC.

EFFECTS OF HOT-ROLLING PROCESSES ON THE FRACTURE BEHAVIORS AND MECHANICAL PROPERTIES OF 2009Al/SiCp METAL MATRIX COMPOSITES

Defects such as pores and weak interfacial bonding in SiC-reinforced aluminum-matrix composites (AMCs) limit the reinforcement effect. The objective of this study is to control the microstructural defects and status of the Al/SiC interface in an 2009Al/SiCp composite using rolling processes. The influence of the rolling reduction rate on the microstructure and mechanical properties is investigated. The fracture behavior of the 2009Al/SiCp composite is observed through in-situ scanning-electron-microscopy tensile tests. The results demonstrate that an appropriate rolling reduction rate can effectively eliminate microstructural defects in the matrix and enhance the interfacial bonding strength of Al/SiC. Plastic deformation during the rolling processes expands the dislocation-strengthening regions near the Al/SiC interface. Consequently, mechanical loads can be more efficiently transferred from the aluminum matrices to SiC particles. In the as-sintered specimens, cracks primarily initiate at the Al/SiC interfaces during tensile tests. In contrast, cracks predominantly propagate from the SiC particles to Al matrices in the as-rolled specimens. This work provides a fundamental understanding of the dynamic changes in the microstructure and the resulting mechanical properties during hot rolling of SiC-reinforced AMCs.

Mirtazapine decreased cocaine-induced c-fos expression and dopamine release in rats.

Chronic cocaine exposure induces an increase in dopamine release and an increase in the expression of the Fos protein in the rat striatum. It has been suggested that both are necessary for the expression of cocaine-induced alterations in behavior and neural circuitry. Mirtazapine dosing attenuated the cocaine-induced psychomotor and reinforcer effects. The study evaluates the effect of chronic dosing of mirtazapine on cocaine-induced extracellular dopamine levels and Fos protein expression in rats. Male Wistar rats received cocaine (10 mg/Kg; i.p.) during the induction and expression of locomotor sensitization. The mirtazapine (30 mg/Kg; MIR), was administered 30 minutes before cocaine during the cocaine withdrawal. After each treatment, the locomotor activity was recorded for 30 minutes. Animals were sacrificed after treatment administration. Dopamine levels were determined by high-performance liquid chromatographic (HPLC) in the ventral striatum, the prefrontal cortex (PFC), and the ventral tegmental area (VTA) in animals treated with mirtazapine and cocaine. The quantification of c-fos immunoreactive cells was carried out by stereology analysis. Mirtazapine generated a decrease in cocaine-induced locomotor activity. In addition, mirtazapine decreased the amount of cocaine-induced dopamine and the number of cells immunoreactive to the Fos protein in the striatum, PFC, and VTA. These data suggest that mirtazapine could prevent the consolidation of changes in behavior and the cocaine-induced reorganization of neuronal circuits. It would explain the mirtazapine-induced effects on cocaine behavioral sensitization. Thus, these data together could support its possible use for the treatment of patients with cocaine use disorder.

Hybrid fiber reinforced ultra-high performance coal gangue geopolymer concrete (UHPGC): Mechanical properties, enhancement mechanism, carbon emission and economic analysis

The low carbonization of ultra-high performance concrete (UHPC) has become a hot topic for sustainable development in the construction industry. Calcined coal gangue was used as aggregate and binder to prepare ultra-high performance coal gangue geopolymer concrete (UHPGC) in this paper. The hybrid reinforcement effect of steel fibers, calcium carbonate whiskers (CW), and carbon nanotubes (CNTs) on UHPGC was studied in the experiment. The results indicated that when the mixing ratio of straight steel fibers and hooked-end steel fibers was 2:1, the 28 d-compressive strength of UHPGC reached 145.94 MPa. However, excessive hooked-end steel fibers deteriorated the reinforcement effect of adjacent fibers and reduced the mechanical properties of UHPGC. CW and CNTs had a more significant improvement in the flexural properties of UHPGC. The bridging effect of CNTs and CW dispersed the stress on the matrix and delayed the formation and development of micro-nano cracks. Meanwhile, CNTs and CW improved the fiber bridging energy dissipation, thereby improving the flexural properties of UHPGC. The UHPGC had the highest flexural strength and flexural deflection of 13.59 MPa and 4.12 mm, respectively. The UHPGC prepared in this paper had lower carbon emissions and economic costs compared to traditional UHPC. Overall, this study provided valuable references for the resource utilization of coal gangue and the multi-scale strengthening and toughening of UHPGC.

Reinforcement of Insufficient Transverse Connectivity in Prestressed Concrete Box Girder Bridges Using Concrete-Filled Steel Tube Trusses and Diaphragms: A Comparative Study

To address the issue of insufficient transverse connectivity in prestressed concrete box girder (PCB) bridges, this study investigates two transverse strengthening methods—installing diaphragms and utilizing concrete-filled steel tube trusses (CFSTTs). A finite element model was developed for a typical 30 m PCB bridge and was validated by on-site load test results for reliability. Based on the deflection and load distribution of PCB bridges before and after reinforcement, as well as the maximum stress and strain of the diaphragms and the CFSTTs, comparative analyses were conducted on diaphragms of different thicknesses and materials, as well as on CFSTTs of various strength grades. The results show that the addition of a transverse partition and CFSTTs can effectively improve the load distribution of the PCB bridge and reduce the maximum deflection of the girder, especially when using the CFSTT reinforcement method. The unique structural design improves the reinforcement effect of the material in the post-elastic stage. When using CFSTTs, increasing the steel tube wall strength significantly reduces the maximum deflection of the main girder. For example, using steel tubes with yield strengths of 235 MPa and 420 MPa filled with concrete of 50 MPa compressive strength reduced the maximum deflections by 15.32% and 24.55%, respectively, and improved the load distribution coefficients by up to 7.31% and 11.57%. Additionally, steel diaphragms demonstrated better reinforcement effects compared with concrete diaphragms. The load transverse distribution coefficients for the CFSTT-reinforced PCB bridge were calculated using the hinge plate (beam) and the rigid plate (beam) methods, showing minimal differences between the two approaches. The findings of this study provide valuable insights into the design of diaphragm and CFSTT reinforcement in PCB bridges, aiding in the selection of optimal reinforcement strategies.

Numerical and experimental behavior of fiber reinforced polymer type and layer number effect on the flexural properties of heat-treated black pine wood

Heat treatment is one of the environmentally friendly methods applied to improve the structural properties of wooden materials. While heat treatment improves some properties of wood material, it also negatively affects its mechanical properties depending on the heat treatment conditions applied. The decrease in mechanical properties due to heat treatment limits the use of wood material in various applications requiring mechanical strength. For this purpose, various fiber-reinforced polymers have been used in recent years. In this study, it was aimed to experimentally and numerically examine the flexural properties of unheat-treated and heat-treated black pine (Pinus nigra Arnold.) wood reinforced 1, 2 and 3 times with carbon, glass and aramid. Following the experimental flexural tests, the samples were modeled and analyzed in the finite element software program. The average flexural strength of the heat-treated sample is 11.72% lower, and the elasticity modulus is 1.23% lower than the unheat-treated sample.It has been determined that carbon-based polymer fabrics, among fiber-reinforced polymer fabrics, have the best reinforcement effect. The flexural strength of the UHT-C-3 sample is 6.1% and the elasticity modulus is 3.52% higher than the UHT-C-1 coded sample. Compared to the sample without reinforcement, flexural strength increased by 30% and elasticity modulus increased by 7%. It is seen that as the number of fiber reinforced polymer layers increases, the flexural properties also increase. When the experimental and numerical analysis results were examined, the flexural strength and modulus of elasticity values gave similar results at the R2: 0.88–0.99 level. In addition to technologies using kinds of reinforcement evaluated in conservation applications, it may be utilized for numerical analysis in the field of repairing or reinforcing different grades, patterns, and types of reinforcement in already-existing wooden structures.

Mechanical strength of rubberized concrete: Effects of rubber particle size, content, and waste fibre reinforcement

Concrete production, ubiquitous in global construction, exerts significant environmental strain, notably through cement manufacturing's carbon footprint and natural sand depletion. As a response, researchers are exploring eco-friendly alternatives, including Waste Tyre Rubber (WTR) aggregates which replace natural sand in concrete. This study investigates the impact of WTR particle sizes (ranging from 0.2 to 4 mm) and volumetric replacements (0–54 %) on Rubberised Concrete Mortar (RuCM) and Rubberised Concrete (RuC) mechanical properties. Additionally, Waste Tyre Steel Fibre (WTSF) reinforcement effects (volume dosage between 0 % and 3 %) are examined and compared with Commercial Steel Fibre (CSF). The study optimizes RuCM and RuC mixes via particle packing theory, incorporating Ground Granulated Blast Furnace Slag (GGBS) and Fly Ash (FA) as cement replacements. Mechanical tests reveal the compressive and flexural strength reduces with an increasing WTR dosage, attributed to the inherent softness of WTR and the weak interfacial bonding between WTR particles and surrounding matrix. Utilizing an optimized RuC mixture with a 10 % WTR replacement yields substantial mechanical improvements, showcasing a remarkable 195 % surge in compressive strength and a noteworthy 61 % elevation in flexural strength over conventional concrete (CC). However, when compared to the control mix devoid of rubber replacement, there is a modest reduction of 16 % in compressive strength and 4 % in flexural strength. Moreover, the incorporation of WTSF reinforcement proves beneficial in mitigating compressive strength losses post rubber particle inclusion and brings about a substantial increase in flexural strength with 3 % volumetric additions. Quantitative analysis reveals the reinforcement effect from WTSF is comparable to the effect of CSF reinforcement. These findings underscore the intricacies and potential opportunities in harnessing WTR and WTSF for the development of resilient and sustainable concrete formulations.

Physical model case study: treatment effect of soft ground by vacuum preloading combined with liquid bag pressurization method

Vacuum preloading and composite ground reinforcement are commonly used methods for reinforcing soft soil, but there is a lack of integrated design method for vacuum preloading combined with composite ground. This case study introduces an innovative approach that combines vacuum preloading with liquid bag pressurization to achieve the integrated design of consolidation drainage method and composite ground reinforcement, which is different from the reported air bag pressurization. To illustrate the effectiveness of this method. Model tests were carried out to analyze the variation of water discharge, pore water pressure, ground settlement, and average consolidation degree in the process of vacuum consolidation. The study investigated the water content, undrained shear strength, and ground bearing capacity of composite ground after ground treatment. A correlation between average undrained shear strength and characteristic value of ground-bearing capacity was established to evaluate and predict the treatment effect of composite ground. Research shows that compared with traditional vacuum preloading, the undrained shear strength can be increased by 13.78%–65.08%, and the characteristic value of bearing capacity for the composite ground can be enlarged by 2.3–4 times. These results indicate that the vacuum preloading combined with liquid bag pressurization can significantly improve reinforcement effect on soft ground.

Experimental study on the creep acoustic emission of fractured sandstone reinforced by anchor rods

To investigate the reinforcement and crack-stopping effect of anchor rods on fractured rock masses, Triassic sandstone from the Xiaolangdi Reservoir area was selected and fabricated into double-fractured specimens. Subsequently, 1 and 2 horizontal anchor rods were used to reinforce the double-fractured sandstone specimens sequentially. Using the RLJW-2000 rock rheological servo tester and the PCI-II type acoustic emission (AE) tester, indoor uniaxial compression creep and AE tests were conducted under the same experimental conditions for the unanchored, singly-anchored, and doubly-anchored sandstone specimens. Based on the experimental results, the creep mechanical characteristics and the three-dimensional spatial evolution of the AE events of the specimens with different numbers of anchor rods were analysed. This study focuses on the reinforcement and crack-stopping effect of anchor rods on fractured rock masses. The experimental results indicate the following: (1) Compared with those of the unanchored specimens, the creep failure strengths of the singly- and doubly-anchored specimens increase by 7.79 % and 22.14 %, respectively. (2) At a stress level of 60 MPa, the axial strains of the single-anchor and double-anchor specimens decreased by 8.41 % and 32.97 %, respectively, compared to the corresponding strain of the unanchored specimen, and the radial strains decreased by 9.21 % and 28.13 %, respectively. (3) Anchor rods have a good reinforcement effect on fractured sandstone, enhancing specimen strength and reducing deformation. (4) With an increase in the number of anchor rods, the reinforcement effect of anchor rods on fractured rock masses strengthened, and the reinforcement effect of double anchors was superior to that of single anchors. (5) Compared with those of the unanchored specimens, under relatively low stress levels, when the AE events extended to the area where the anchor rods were located, the number of AE events for both types of specimens decreased significantly, forming a blank area in the AE events, and the blank area of the double-anchored specimens was larger than that of the single-anchored specimens. (6) With increasing stress, many AE events originated, expanded, and passed through the anchor rod area, indicating that the specimen was about to undergo creep instability failure. (7) The evolution characteristics of the AE events are in good agreement with those of the macroscopic cracks on the specimen surface. The AE characteristics indicate that anchor rods have a significant crack-stopping effect on fractured rock masses, suppressing the initiation, expansion, connection, and penetration of internal microcracks in the specimens. Moreover, the crack-stopping effect of double anchors is superior to that of single anchors.

Seismic performance assessment of stone masonry buildings: Efficacy of various strengthening elements

Post the 2015 Gorkha earthquake in Nepal, various codes and guidelines were introduced and implemented to enhance the seismic resistance of masonry structures. These provisions encompass diverse seismic measures such as incorporating horizontal bands and vertical reinforcements to fortify structures against seismic forces. Nevertheless, a comprehensive investigation and validation of effectiveness of horizontal bands and vertical reinforcement on the performance of such buildings is still lacking. This paper addresses this gap by presenting the seismic fragility assessment of stone masonry buildings constructed with mud mortar (SMM) and cement mortar (SMC), with a case study involving three distinct building prototypes, presented in the catalogue by the Department of Urban Development and Building Construction (DUDBC), Nepal. The research evaluates the effectiveness of several strengthening components on the buildings' performance, making comparisons among four different scenarios: (a) RM (a reinforced model with all horizontal bands, vertical reinforcement, and through stones), (b) RM-WOV (a reinforced model excluding vertical reinforcement), (c) RM-WOV-St (a reinforced model excluding vertical reinforcement and stitches), and (d) URM (an unreinforced model lacking all horizontal bands, vertical reinforcement, and through stones). The cracking mechanisms reveals the importance of the horizontal bands and through stones. The fragility analysis performed for slight, moderate, extensive and collapse damage states shows that unreinforced models are more susceptible than their reinforced counterparts, irrespective of whether mud or cement mortar is used. The maximum reduction in probability of exceedance of collapse and extensive damage for SMM and SMC buildings with the introduction of horizontal bands at sill and lintel level together with through stones are around 82 % and 81 % respectively. This shows that horizontal bands at sill and lintel level play an important role in preventing the damage of the buildings. Furthermore, it is found that the effect of using vertical reinforcement and horizontal stitches is minimal in preventing the structural damage in cement mortar buildings. However, for mud mortar buildings, these measures have a noticeable effect.

Injection molded lightweight composites from tea-stem fiber and polypropylene: Effect of fiber loading on forming properties and cell structure

China boasts abundant tea resources and substantial production output. To facilitate the high-value utilization of by-products generated during tea production, such as tea stems, thereby reducing resource wastage, this study pioneered the preparation of tea-stem fiber-reinforced polypropylene (TF/PP) composites through microcellular injection and conventional molding processes. The effects of tea-stem fiber (TF) content on the formability of foamed and unfoamed composites were compared and analyzed. The findings reveal that the inclusion of TFs fostered the crystallization of polymer chains, decreased the flowability of the composites in their molten state, and enhanced the density, surface hydrophilicity, and thermal stability of the molded composites. In the unfoamed state, composites with 20 wt%, 40 wt%, and 30 wt% TF content exhibited optimal tensile (35.92 MPa), flexural (58.43 MPa), and impact (6.49 KJ/m2) strength, respectively. Upon foaming, composites with TF contents of 30 wt%, 40 wt%, and 30 wt% demonstrated superior tensile (32.84 MPa), flexural (51.31 MPa), and impact (6.94 KJ/m2) strength, respectively. A 30 % TF content in foamed composites yielded the best reinforcement effect, creating an ideal balance of internal interactions. This resulted in mechanical properties that were close to or even exceeded those of unfoamed PP while reducing the density by nearly 6 %. The results from this study contribute towards the high-value application of tea by-products, promoting the development of the global tea economy.

Research on the Water Inrush Mechanism and Grouting Reinforcement of a Weathered Trough in a Submarine Tunnel

Based on the structural and geological characteristics of the F1 weathering trough of a submarine tunnel and its spatial relationship with the cavern, a simplified calculation model of the weathering trough water inrush was established, and the formation, development process and influencing factors of the water inrush channel in the water-resistant rock layer were carried out by a numerical simulation of particle flow. It shows that the integrity and stability of the critical water-resistant rock mass is the key to preventing water inrush, and the identification and positioning of the water inrush channel is the basis for the grouting reinforcement design of the weathering groove of the submarine tunnel. Based on above research results, the F1 weathering trough was blocked and reinforced by the composite grouting method, and the engineering reinforcement effect was good.

An Easy-to-Integrate Embedded Cascade Microspheres for Efficient Local Field Enhancement

Surface-enhanced Raman spectroscopy (SERS) is a non-destructive and ultra-sensitive tool for optical trace detection. However, the complex manufacturing process hinders the application of SERS. For this reason, an embedded cascaded microsphere structure is proposed in this paper, which is easy to integrate and process. Such a structure is composed of large microspheres and small microspheres with micropores cascaded. More importantly, the micropore diameter at the bottom of the large microspheres is the same as that of the small microspheres. Through the finite element analysis, it is concluded that compared with a single microsphere, the photonic nanojet generated by this structure is stronger, which can achieve local electric field enhancement more effectively. Meanwhile, different materials of the cascade microspheres used in the embedded cascade have various reinforcement effects. In addition, compared with the manual physical alignment of two microspheres in the traditional cascade structure, this structure is easier to process and integrate, convenient for future integrated applications.

Effect of Glass Fiber Reinforcement on Bearing Capacity and Settlement of Foundations on Soft Clay

Effect of Glass Fiber Reinforcement on Bearing Capacity and Settlement of Foundations on Soft Clay

Influence of nano graphene filler on hardness, impact strength and density of glass epoxy composites

AbstractThis study investigates the effects of graphene reinforcement on the hardness and impact strength of glass epoxy composites. Four different materials were examined: pure epoxy (EP), glass epoxy (GE), glass epoxy with 1 wt.% graphene (GE1), and glass epoxy with 2 wt.% graphene (GE2). The results show that the incorporation of graphene significantly enhances the hardness of the composites. Pure epoxy (EP) exhibited a Shore D hardness of 60 and an impact strength of 0.09 J/m2. The glass epoxy (GE) showed a reduction in hardness to 56 but an increased impact strength of 0.15 J/m2 due to the inclusion of 33 wt.% glass fiber. Further addition of graphene in GE1 and GE2 led to notable improvements in hardness, reaching 68 and 74 Shore D, respectively. However, the impact strength displayed a decrease with the inclusion of graphene, with GE1 and GE2 showing values of 0.13 and 0.11 J/m2, respectively. When transitioning from pure epoxy (EP) to glass epoxy (GE), there is a 6.67% decrease in hardness, while the impact strength increases by 66.67%. Introducing 1 wt.% of graphene to the glass epoxy (GE1) results in a 21.43% increase in hardness but a 13.33% decrease in impact strength. Further adding 2 wt.% of graphene (GE2) leads to an additional 8.82% increase in hardness, though the impact strength decreases by 15.38%. X‐ray diffraction (XRD) analysis has revealed nano graphene presence and distribution, while fractography has revealed its effectiveness in enhancing interfacial adhesion and toughening mechanisms. Furthermore, XRD identifies potential changes in crystallinity or phase composition induced by nano graphene incorporation, further elucidating the composite's structure and properties. The study highlights the novel and significant trade‐offs encountered in optimizing the mechanical properties of epoxy‐based composites by incorporating graphene and glass fiber.

Seismic response investigation of prestressed anchor cable supporting rock slope with weak interlayer in Qinghai-Tibet Plateau, China

Earthquake-induced rock landslides in the eastern mountains of the Tibetan Plateau, especially landslides with weak interlayers pose a significant threat to major construction projects. Prestressed anchor cable is one of the main reinforcement methods of rock slopes. This paper combines shaking table model tests and numerical simulation to study the reinforcement effect and dynamic response characteristics of prestressed anchor cables applied to rock slopes with weak interlayers under strong earthquakes. The research results show that prestressed anchor cables can effectively reinforce slopes with weak interlayers. A small cable inclination, a small spacing and a high prestress are recommended in the seismic reinforcement design of prestressed anchor cable. In addition, the characteristics of slope progressive damage and prestress loss under the earthquake are found by the shaking table test. The results have been applied in hazard prevention and control of rock slopes on the Chengdu-Lanzhou Railway at the eastern Qinghai-Tibet Plateau.

Wages and Inflation in the Euro Area

Abstract We investigate the relationship between the four main inflation components (services, NEIG, energy, and food) and wages in the euro area. Using a panel vector autoregressive (PVAR) model for the 2002q1–2021q4 period, we find that wages positively respond to shocks in services inflation, energy inflation and GDP growth, with the first being the largest. In addition, services inflation is affected by all other inflation categories. The results are in line with the inflation path since 2022, following the food and energy price surges. Implications for policy include a feedback loop between wages and services inflation that lasts at least a year, with a possible reinforcement effect stemming from inflation expectations. Similar to US evidence, we also find that the unemployment rate does not affect wage developments in a Phillips curve setup. (JEL codes: J30, E24, E31)

Laser treatment of (Zr-Ta-W-Ti)C-SiC based high entropy carbide ceramics reinforced with carbon nanotubes, graphite and graphene nanoplatelets

This study investigates the effect of laser surface treatment on spark plasma sintered (Zr-Ta-W-Ti)C-SiC (ZTaWT-S) based high entropy ceramic (HEC) composites, reinforced with multiwalled carbon nanotubes (CNT) (ZTaWT-SC), graphite (ZTaWT-SG), and graphene nanoplatelets (GNP) (ZTaWT-SGNP). The increased hardness of the laser-treated composites (25–33 GPa) when compared to that of untreated composites (23–28 GPa) is attributed to the high compressive residual stresses, ranging from 1400 to 2900 MPa. The laser-treated ZTaWT-SGNP composite exhibited a minimum scratch wear rate of ∼0.9 × 10−1 mm3/N.m, representing a 57 % and 73 % reduction compared to the untreated ZTaWT-SGNP and the laser-treated ZTaWT-S, respectively. ZTaWT-SGNP composite demonstrated the best resistance to damage accumulation, due to the synergistic effects of laser treatment and GNP reinforcement, enhancing its suitability for extreme environments.

Effect of the lateral area of graphene nanosheets on the strengthening mechanism in FGH96 superalloy composites

To improve the strengthening effect of graphene reinforcement in nickel-based superalloys, introducing graphene nanosheets (GNSs) with multiple lateral areas into the GNS/metal system is a promised strategy to take full advantage of the superior properties of graphene reinforcement. In this work, the impact of the GNS lateral area on the strengthening effect of FGH96 nickel-based superalloy composites (DLA-GNS/FGH96) was investigated for the first time. Microstructural and tensile tests revealed the uniform distribution of the GNSs in the DLA-GNS/FGH96 metal matrix with lateral areas ranging from 0.06 ± 0.02 to 225.2 ± 20.3 μm2. The GNSs exhibited a well-balanced mechanical property on the elongation and yield strength of the DLA-GNS/FGH96 composites. Investigation of the fracture morphology and mechanism indicated that there existed a transition of the strengthening mechanism (between the strengthening mechanism of Orowan and the strengthening mechanism of load-transfer) for the GNSs, which was closely associated with the lateral area of the GNSs. This finding put forward new ideas to better comprehend the strengthening mechanisms of GNS-reinforced metal-matrix composites.

Influence of Polymer Fibre Reinforcement on Concrete Anchor Breakout Failure Capacity.

With the increasing use of fibre-reinforced concrete, e.g., in industrial floor and tunnel construction, the associated fastening technology in this material has increasingly become the focus of scientific attention in recent years. Over 25 years ago, design and assessment guidelines for anchoring systems in reinforced concrete were established, which have since evolved into comprehensive regulatory standards. However, these standards only address plain and rebar-reinforced concrete as anchoring bases, neglecting fibre-reinforced concrete. The design of anchorage systems in fibre-reinforced concrete has not yet been standardised. Recent studies and product certifications accounting for steel fibre reinforcement are now seeing their way to publication, supported by a fair amount of scientific research studies. This paper aims to elucidate the effects of polymer fibre reinforcement in this application through a systematic investigation. Experimental studies were conducted to evaluate the system's load-bearing behaviour failing with concrete breakouts under tensile loading. By incorporating the determined material properties of polymer fibre-reinforced concrete and their mathematical interpretation, alternative model proposals are presented to assess concrete breakout resistance. The addition of polymer fibres significantly improves the load-bearing capacity and ductility of concrete under tensile loads, transforming its quasi-brittle response into a more ductile behaviour. Although the fibres had a minor impact on overall material strength, their influence on the tensile capacity of the anchors reveal a 15-20% increase in load resistance and up to a doubling of the failure displacements.