High Compressive Strength Research Articles

Sustainable surface coating strategy for the Interface compatibilization of hybrid high-density polyethylene microfibers and geopolymer-based composite: A versatile path for an efficient brittle to ductile-like transition

Geopolymer-based mortars (GMs) are known for their high compressive strength, but their brittleness under tensile and bending loads has limited their structural applications. To overcome these challenges, enhancing the fiber-matrix interface in fiber-reinforced GMs is crucial to achieve better load transfer. In this study, we employed an eco-friendly, non-invasive, and scalable surface coating method by dispersing metakaolin particles on the fiber surface. The fibers' chemical structure, morphology, thermal stability, and mechanical properties were analyzed, confirming the successful treatment with no major defects. When incorporated into GMs at 0.3 wt.%/binder, the treated fibers achieved remarkable mechanical improvements, including a 1,065% increase in flexural toughness, a 190% rise in flexural strength, and notable strain-hardening behavior, marking a transition from brittle to ductile-like failure. Additionally, the flexural modulus, split tensile strength, and compressive strength increased by 92%, 154%, and 7%, respectively. These results demonstrate the effectiveness and the potential of such a simple and sustainable fiber compatibilization strategy in developing durable, high-performance fiber-reinforced geopolymer composites for construction applications.

Preparation of La2Ce2O7 porous ceramics with low thermal conductivity and high compressive strength by in-situ pore-forming-hinder-assisted method

Preparation of La2Ce2O7 porous ceramics with low thermal conductivity and high compressive strength by in-situ pore-forming-hinder-assisted method

Top-Down Strategy Enabling Elastic Wood Nanocarbon Sponges with Wrinkled Multilayer Structure and High Compressive Strength for High-Performance Compressible Supercapacitors.

3D porous carbon electrodes have attracted significant attention for advancing compressible supercapacitors (SCs) in flexible electronics. The micro- and nanoscale architecture critically influences the mechanical and electrochemical performance of these electrodes. However, achieving a balance between high compressive strength, electrochemical stability, and cost-effective sustainable production remains challenging. Here, a superelastic wood nanocarbon sponge (WNCS) with a wrinkled multilayer structure is developed via a facile "top-down" design on natural wood. These unique wrinkled nanolayers effectively alleviate stress concentration through elastic deformation, resulting in a high compressive strength of 580.6kPa at 70% reversible strain. The significantly increased specific surface area, coupled with abundant micro-mesopores and highly graphitized nanocarbon, promotes rapid ion/electron transport, enabling the WNCS to achieve an ultrahigh capacitance of 4.21Fcm-2 at 1mAcm-2, along with excellent cyclic stability and rate capability. Furthermore, an asymmetric supercapacitor (ASC) using a WNCS anode and a NiCo-layered double hydroxide cathode retains 71.8% of its initial capacitance after 1000 compression cycles and withstands stress up to 1.03MPa without capacitance degradation. This sustainable, cost-effective WNCS shows great promise for flexible, compressible, and wearable electrochemical energy systems.

Combined Impact of Nano-SiO2 and Superabsorbent Polymers on Early-Age Concrete Engineering Properties for Water-Related Structures

High-performance concrete (HPC) is currently widely used in water-related structures. The incorporation of nano-silica (nano-SiO2, NS) can further refine its pore structure, thereby enhancing the compressive strength and durability of HPC without necessitating a reduction in the water-to-binder (w/b) ratio. However, the addition of nano-materials significantly increases the autogenous shrinkage (AS) of concrete, leading to elevated tensile stresses and making the concrete more susceptible to early-age cracking. To mitigate AS, superabsorbent polymers (SAPs) can be introduced to internally cure the concrete, thereby improving the internal relative humidity (IRH) and reducing the AS in NS-reinforced concrete. In this study, we experimentally investigate the setting behavior, pore structure, compressive strength, IRH, and AS properties of concrete with a w/b of 0.3, incorporating both NS and SAP. The results demonstrate that the addition of NS advances setting time, significantly densifies the pore structure, markedly enhances compressive strength, accelerates the decline in IRH, and increases AS strain. Conversely, the incorporation of SAP exhibits opposite effects on these properties, particularly in substantially mitigating AS strain. The combined incorporation of 1.5% NS and 0.15% (or 0.30%) SAP achieves both higher compressive strength and lower AS strain compared to plain concrete at 28 days. These findings suggest that the simultaneous introduction of NS and SAPs into concrete formulations is recommended to achieve an optimal balance between shrinkage and strength properties. Such advancements are particularly beneficial for applications in hydraulic and water-related structures, where enhanced durability and reduced cracking are critical for maintaining structural integrity and ensuring longevity.

Template-Thermally Induced Phase Separation-Assisted Microporous Regulation in Poly(lactic acid) Aerogel for Sustainable Radiative Cooling.

Herein, an eco-friendly and degradable poly(lactic acid) aerogel was prepared by combining a poly(ethylene glycol) template material with thermally induced phase separation. Due to the tailored pore size introduced by the template material, the aerogel exhibits high solar reflectance (92.0%), excellent thermal emittance (90.5%), low thermal conductivity (52.0 mW m-1 K-1), and high compressive strength (0.15 MPa). Cooling tests demonstrate that the aerogel can achieve temperature drops of 3.7 °C during the day and of 6.2 °C at night. Furthermore, simulations of building cooling energy systems reveal that the aerogel can reduce energy consumption by 2.2 to 10.2 MJ m-2 per year in various cities, achieving energy savings ranging from 8.2 to 24.3%. Meanwhile, the aerogel cooler demonstrates excellent self-cleaning performance (WCA = 149.1°) and cyclic compression performance. This research will promote the field of passive radiative cooling toward a greener and more sustainable direction.

Influence of surfactant type on the microstructure, mechanical and thermal properties of phenolic foams

Surfactant chemistry can affect the phenolic foam (PF) properties by controlling the collision and combination of the created bubbles during foam production. The study was accomplished using two surfactant families, nonionic: polysorbate (Tween80) and anionic: sodium and ammonium lauryl sulfates (SLS30 and ALS70) and sodium laureth sulfate (SLES270) to manufacture PF foams. Tween80 and SLS30 resulted in foams with the lowest and highest densities, 20.2 ± 0.2 and 42.72 ± 0.4 kg/m3, respectively. All the surfactants created an open-cell morphology, except Tween80 with a semi-open-cell structure consisting of large cells and thicker cell wall thickness. The anionic surfactant had better performance, the foams made by SLS30 had cells with diameters of 338.5 ± 18.5 and cell density of 2.5 cell/mm3 × 105. While the SLES270 made foam with the highest cell density and the smallest cell size that caused higher compressive strength. The SLES270 led to keeping the foam flexibility even under the fire exposition, and it increased the thermal insulation by 50% while the other samples were turned into fragile foam. A higher level of polarity in SLES270 caused better micelle production and then better bubble formation, followed by the bubble coalition.

Preparation and Characterization of a High Compressive Strength Polyamide 12T Microcellular Composite Foam Loaded With Short‐Chain Carbon Fiber and In Situ Generated Polytetrafluoroethylene Nanofiber

Preparation and Characterization of a High Compressive Strength Polyamide <scp>12T</scp> Microcellular Composite Foam Loaded With Short‐Chain Carbon Fiber and In Situ Generated Polytetrafluoroethylene Nanofiber

A safe highway driving surface using an open graded concrete

The use of open graded asphalt wearing courses for highway pavements is established technology but the opportunities to use a similar cementitious based surface type for concrete pavements has been limited by material technology and costs. Research work in Australia using new generation concrete admixtures and placing techniques has allowed the development of a stiff open graded concrete material which is expected to meet the same durability requirements as standard concrete used for roads. Open graded surface textures absorb vehicle noise emissions and minimise water film build up during rain events, thus resulting in quieter and safer driving conditions. In addition, experience has shown that high void contents at the surface assist in reducing water spray generation and glare reflection. This paper details the laboratory mix design test results and three field trials using hand placing techniques to define the limits of a wet on wet construction process. The concrete developed in the trials has high compressive strength with air voids in the range of 20 to 30%. The next stage in the development of the open graded concrete surfacing is in the use of mechanised placing techniques to make the process cost competitive to other asphalt alternatives and yet meet similar durability requirements to those currently expected in concrete road surfaces over a 40 year design period.

Compressive damage in super‐thick cross‐ply composites

AbstractThe compressive behavior of super‐thick composites was examined. The specimens were composed of 160 carbon/epoxy layers stacked in cross‐ply with 24 mm in thickness. A term “equivalent layer number (ELN)” is defined, representing the number of contiguous layers stacked in the same direction. Six specimen types were made with ELNs varying from 80 to 2. The results showed that the compressive strength consistently increases when the ELN is decreased. Compared with the ELN‐80, the ELN‐2 is 65% stronger. In all specimens, the initial damage was the formation of kink‐bands. However, the kink‐band growth was affected by the layup. In larger ELNs, the kink‐bands are developed in a zigzag form within the same axial group. In smaller ELNs, kink‐bands are aligned, crossing different axial groups. The damaged states were recorded in the entire loading course, allowing correlation between the damage state and the loading curve. In the final stages of loading, two modes become dominant: large‐scale delamination and long shear‐cuts. The ELN affects not only the strength but also the evolution of damage in the specimens. A smaller ELN is preferable, as the laminate becomes stronger, and the induced damage is more diversified.Highlights Super‐thick composites made and tested in compression. Smaller ELNs resulting in higher compressive strength. Larger ELNs leading to zigzag kink‐bands and large‐scale delamination. Smaller ELNs leading to aligned kink‐bands and shear‐cut failure.

Supercritical CO2-Stable Cementing Materials Based on Vinyl Ester Resin for Maintaining Wellbore Integrity.

Ensuring long-term wellbore integrity is critical for carbon dioxide geological storage. Ordinary Portland cement (PC) is usually used for wellbore primary cementing and plug operation, and set cement is easily corroded by acidic fluids, such as carbon dioxide, in underground high-temperature and high-pressure (HTHP) environments, resulting in a decrease in the mechanical properties and an increase in permeability. In order to achieve long-term wellbore integrity in a CO2-rich environment This study introduces materials such as thermosetting vinyl ester resin (TSR), filler composite resin (FCR), and low-cost resin cement (RC). Corrosion experiments were conducted using four materials in 28 days under supercritical carbon dioxide gas and water phase conditions of 60 °C and 10 MPa. The samples were characterized through mechanical property testing machines, core permeability measuring instruments, FTIR, XRD, and SEM. The results proved that after corrosion, PC mechanical properties decreased, the permeability increased, and the microscopic composition and morphology changed greatly. Penetrating corrosion occurs in the sample in the gas phase environment, and propulsive corrosion from outside to inside occurs in the water phase environment. However, TSR, FCR, and RC materials all maintain excellent resistance to carbon dioxide corrosion in gas and water environments. They have higher compressive strength and extremely low permeability compared to ordinary Portland cement. These three materials' compressive strengths can be maintained around 131, 99, and 58 MPa, and permeability can be stabilized at <6 × 10-7, <6 × 10-7, and 0.16 mD levels. In summary, the above three materials all show better performance than ordinary Portland cement and are promising alternative materials that can be used in primary cementing and plug operations of carbon dioxide geological storage wells.

Role of calcination process of natural colemanite powder on compressive strength property of concrete.

The use of boron minerals as an additive is important in terms of reducing CO2 emissions and providing input to the economy. Sustainable natural colemanite was subjected to calcination at 550°C in order to concentrate the amount of B2O3. For the characterization of calcined mineral, XRD, TGA/DTA, and B2O3 component tests were carried out. It was observed that the structure of natural colemanite changed, and the B2O3 value heightened by 11%. Then, natural and calcined minerals were added to the concrete mixture in proportions of 1.25%, 2.5%, 5%, 7.5%, 10%, 12.5%, and 15% by weight. Ultrasonic pulse velocity, Schmidt hardness, and compressive strength tests were fulfilled. In the samples with natural additives, the lowest compressive strength was 32MPa for the reference sample, whereas the highest strength was 44MPa for the 10% natural colemanite sample. In other words, the compressive strength increased by 39%. In the samples with calcined additives, the highest compressive strength was 30MPa for the 2.5% calcined colemanite sample; that is, it improved by 24%. It is realized that the cement can be saved since high strength can be obtained in concrete with natural and calcined colemanite additives.

Preceramic polymer-hybridized phenolic aerogels and the derived ZrC/SiC/C ceramic aerogels with ultrafine nanocrystallines.

Phenolic and carbon aerogels have important applications for thermal insulation and ablative resistance materials in aerospace field. However, their antioxidant ability in long-term high-temperature aerobic environments faces serious challenges. To solve this problem, Zr/Si preceramic polymer hybridized phenolic resin (PR-ZS) aerogels were prepared via a facile sol-gel method. Compared with pure phenolic aerogel, the hybrid aerogels possess similar porous microstructure but larger specific surface area, better thermo-oxidative stability, and higher compressive strength. After carbonization at 1700 °C, the hybrid aerogels can be transformed to carbide ceramic aerogels with ultrafine nanocrystalline ZrC and SiC particles embedded in the carbon matrix. Ceramic aerogels exhibit good thermal insulative and anti-ablative properties in a butane torch simulated high-temperature and aerobic environment. The linear ablation rate is as low as 0.017 mm min-1, and the backside temperature is below 330 °C at a 20 mm in-depth position after 300 s of burning test, when the front temperature is approximately 960 °C. This work provides a facile approach to fabricate hybrid phenolic aerogels and derived ZrC/SiC/C ceramic aerogels, which target on applications for extreme environments in aerospace field.

Toughening of thermoset composites using glass/polypropylene commingled stitching yarns.

This paper investigates the damage resistance and tolerance of thermoset composite laminates stitched by glass and hybrid glass/polypropylene commingled yarns. Different impact energies (10-70J) were applied to stitched composite laminates before compression after impact (CAI) tests were conducted. The results showed that, except for 70J, commingled yarn-stitched laminates absorbed more energy than glass-stitched laminates. Compression tests revealed that glass-stitched and commingled composites had, respectively, 2% and 5% higher compressive strengths than unstitched laminates. After being impacted to 10-70J energies, glass yarn stitched laminates kept 83-36% of their compressive strength, while commingled yarn stitched laminates retained 73-40%, showing that the commingled yarns were more efficient at higher energies. The study found that integrating plastically deformed fibres into hybrid stitching yarns increased energy absorption and composite fracture mechanism by encouraging fibre/matrix debonding, resulting in fewer fibre breakages.

The effect of travertine waste on the strength and insulation properties of foam concrete

Abstract Incorporating waste additives into foam concrete mixtures is a promising route to develop environmentally-friendly concrete production with tailored thermos-mechanical properties. In this paper, the effects of various fabrication parameters of foam concrete, including the type of waste additive, water/binder ratio, density of mixture, and incorporation of glass fibers were investigated. Foam concrete samples were fabricated using fly ash and travertine wastes, and the variations in their flexural strength, compressive strength, and thermal conductivity using various concrete mixture designs were measured. The obtained results show that foam concrete with fly ash additive tends to have higher compressive strength and thermal conductivity than foam concrete with travertine waste. However, the latter exhibits better thermal insulation properties, which tend to improve by adding glass fibers. This work defines the outlines for exploring the use of harmful wastes in fabricating foam concrete. It offers guidelines for developing improved foam concrete mixtures with tailored thermos-mechanical properties.

Fracture behavior of NiNb and NiNbP bulk metallic glasses

While it is known that phosphorous additions enhance the hardness, strength, and glass forming ability of NiNb(P) bulk metallic glasses, nothing is known about the trade-offs regarding the fracture characteristics. The fracture toughness and bending deformation behavior of Ni62Nb38 and Ni59.2Nb38.8P2 BMGs were studied, both of which have been reported to have very high compressive yield strength near 3GPa. The binary NiNb BMG exhibited ~4% plastic bending strain and a precracked fracture toughness of KQ = 50MPa√m which gives an excellent combination of strength and toughness relative to other engineering materials. With the addition of 2at.% phosphorus, the glass forming ability was maximized, but the BMG was hardened and embrittled, fatigue precracking was no longer possible, and micronotched toughness values, which should overestimate the precracked fracture toughness, were in the range of KQ = 19 − 26MPa√m. Additionally, a progressive hardening and bending embrittlement was observed for intermediate P additions of 1 and 1.5at.% phosphorus. Transmission electron microscopy revealed larger medium range order clusters in the relatively softer NiNb BMG which were thought to contribute to easier shear transformations and plastic deformation by shear banding.

High Initial Concrete Compressive Strength with Variations of Superplasticizer and Silica Fume Additions

High Initial Concrete Compressive Strength with Variations of Superplasticizer and Silica Fume Additions

Self-powered composites by bioinspired device-to-material integration.

The booming Internet of Things will generate diverse requirements for specialized power sources featuring customizable mechanical properties and shapes. However, these features are usually challenging to achieve with traditional batteries. Here, we report the design of self-powered composites (SPCs) by a bioinspired device-to-material integration (DTMI) strategy to break the above shackles. Specifically, commercially cheap small coin cells are employed as functional cell fillers for polymer composites, which are united by bioinspired conductive connections. Meanwhile, the polymer host is 3D printed with a bioinspired configuration to increase the energy density and achieve customizable shapes. The results show that commercial small coin cells (CR927) can work as reinforcement and functional fillers for polymer composites with a high electrochemical compression strength of 158 MPa, as revealed by in situ electrochemical mechanical testing. Via the DTMI strategy, SPCs have been successfully fabricated with either high mechanical strength or stretchability. Enabled by these features, SPCs are further demonstrated to be promising building blocks for self-powered electrical vehicles and wearable electronics. Moreover, a stretchable SPC with slidable cell-connection is demonstrated as a smart sensor for stretching rate due to an electrochemistry-polymer relaxation coupling process. This study may open an avenue for self-powered materials for electrical vehicles, robotics, wearable electronics, and beyond.

Comprehensive Study of Sub-micron Porous Titanium-zirconium Scaffolds Fabricated by Liquid Metal Dealloying

This article investigates the microstructure, mechanical properties and biocompatibility of ultrafine porous titanium-zirconium (TiZr) alloys synthesized by the liquid metal dealloying (LMD) at a temperature of 1023K for various immersion times. The dealloying of Ti20Zr20Cu60 precursors in molten magnesium causes to self-organize three-dimensional hcp-α structures by surface diffusion mechanism, wherein the ligament size, density and porosity range from 130 to 280nm, 2.8 to 3.2g/cm3 and 0.43 to 0.5, respectively. The compression test results of porous products indicate a perfect combination of high compressive strength (415−620MPa) and low elastic modulus (2.1−3.2GPa) matching that of the human bone. The maximum ligament size (280nm), density (3.2g/cm3) and compressive strength (620MPa) corresponds to immersion time of 600s; thereby, the mechanical characteristics can be tailored by modifying the process parameters. Meanwhile, the elastic modulus and compressive strength enhance almost linearly with increasing the relative density in accordance with the Gibson and Ashby model. The in-vitro experiments with MG-63 osteoblast cells also suggests the immersion time of 600s to better support the bone tissue ingrowth. The porous TiZr alloy fabricated by the new dealloying method can be considered as a novel biomaterial for dental implants owing to its unique microstructure, compressive features and biocompatibility.

Effect of one-part geopolymer filler on the performance of cold bitumen emulsion mixtures

ABSTRACT This study aims to assess the performance of cold bitumen emulsion mixtures modified with a one-part geopolymer based on blast furnace slag and an alkaline activator. This material is generally prepared in a liquid solution, from an aluminosilicate source and an alkaline compound, and is dedicated to the precast sector. In this study, it was obtained by mechanosynthesis, a solvent-free process consisting of high-energy ball milling. The powder was incorporated as a filler in the formulation of 0/10 asphalt mixes. Other cold mixtures with limestone and blast furnace slag filler were manufactured to evaluate the influence of the additive nature on the cohesive strength at different curing times, compressive strength, water sensitivity, rutting resistance and resilient modulus. The potential chemical reactivity between each filler and each emulsion was monitored by in situ Fourier transform infrared spectroscopy. The results pointed out that the cohesive strength of the mixes containing one-part geopolymer is two to three times higher than that of the other formulations after 24 h curing. High compressive strength of the one-part geopolymer-based mixes is noticed; however, their compressive strength ratio is slightly lower, in comparison with the other mixes. The rutting percentage of the one-part geopolymer-based mixes reaches 4% at 30,000 cycles and their resilient modulus above 6,000 MPa at 15 °C. These results are attributed to the geopolymerisation reaction occurring between the filler and the emulsion, traduced by a shift in infrared spectroscopy. Therefore, the addition of one-part geopolymer filler, produced according to a non-solvent process, is a promising solution to enhance the implementation and durability of cold mixtures.

Fabric Reinforced Polybenzoxazine Aerogel Composite With Lightweight, High Compressive Strength, and High‐Temperature Resistance to 1100°C

ABSTRACTHigh‐temperature resistance polymer composites are crucial for application in aerospace field. Polybenzoxazine (PBz) aerogel is a novel insulation material with excellent mechanical properties, low bulk density, and low thermal conductivity, which has potential application in thermal protection systems. However, the improvement of high residual char rates for shape‐keeping purposes at high‐temperature is still a critical challenge. Herein, a novel kind of PBz aerogel composite reinforced with mullite‐fiber fabric (PBZ‐MF) is prepared by sol‐immersion‐gel strategy. The prepared composite integrates the nanoporous structure of aerogel with the fascinating properties of mullite‐fiber fabric, resulting in relatively low thermal conductivity (0.0557–0.0647 W m−1 K−1 at 25°C and normal pressure), lightweight (0.41–0.47 g cm−3), outstanding flame resistance (self‐extinguishing time as short as 0.7 s), and high compressive modulus (20.611–32.656 MPa). Furthermore, PBz‐MF demonstrates exceptional high‐temperature resistance and shape‐keeping properties even at 1100°C. This work provides valuable insights into the development of lightweight insulation materials and expands the potential applications of aerogel composites in thermal protection systems within the aerospace field.