Experimental Investigation on Macroscopic and Microscopic Mechanical Properties of Geopolymer-Stabilized Macadam

Materials, Journal Year: 2025, Volume and Issue: 18(2), P. 454 - 454

Published: Jan. 20, 2025

Geopolymer, as a promising inorganic binding material, holds potential for use in constructing base layers highway pavements. This study aims to evaluate the mechanical properties of geopolymer-stabilized macadam (GSM) at both micro- and macro-scale by series tests, demonstrating that high-Ca GSM is high-quality material pavement layers. The results demonstrated exhibits outstanding fatigue properties, significantly surpassing those cement-stabilized (CSM). Performance improvements were particularly notable with higher binder-to-aggregate ratios. derived from precursor achieved relatively life resistance permanent deformation under cyclic loading, outperforming CSM. Furthermore, relationship models developed indirect tensile test provide valuable framework evaluating GSM’s long-term road performance. Microstructural analyses revealed geopolymer features reticulated gel structure denser, more continuous internal matrix, which contribute its superior properties. interface products GSM, including C–A–S–H C(N)–A–S–H gel, enhance interlocking promote early strength development, accounting exceptional resistance. These findings offer insights technical guidance employing sustainable effective alternative layer construction.

Language: Английский

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From Waste to Roads: Improving Pavement Performance and Achieving Sustainability with Recycled Steel Slag and Low-Density Polyethylene

Buildings, Journal Year: 2025, Volume and Issue: 15(3), P. 476 - 476

Published: Feb. 3, 2025

The use of waste, recycled, and modified materials is increasingly popular in roadway construction for sustainability pavement longevity. This research examines the combination steel slag (SS) low-density polyethylene (LDPE), commonly used plastic bags manufacturing by-products, to mitigate environmental pollution. LDPE was tested as a binder modifier two bitumen grades, 60–70 80–100, at concentrations 3%, 5%, 7% by weight. SS replacement coarse aggregate. physical properties both unmodified grades were analyzed before creating testing hot-mix asphalt (HMA) samples. dynamic modulus these samples measured temperatures 4.4 °C, 21.1 37.8 54.4 °C with frequencies 0.1 Hz, 0.5 1 5 10 25 Hz. Master curves developed, data underwent design experiment (DOE) computational intelligence (CI) analyses. Using KENPAVE, mechanistic–empirical tool, analysis assessed life enhancements damage ratio each grade. results showed that adding increases softening point penetration grade but decreases ductility due increased stiffness, leading premature fatigue failure higher levels. Both 3% SS-modified improved Marshall Stability across all temperature frequency ranges. Specifically, enhanced stability 13–16% SS-LDPE 30–32%. KENPAVE improvement 19–25% reduction 15–18%. In comparison, demonstrated 50–60% 25–35%. Overall, this study concludes LDPE- SS-LDPE-modified HMA 80–100 provide optimal improving performance.

Language: Английский

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Using One-Part Geopolymer in Stabilizing High-Water-Content Soft Clay: Towards an Eco-Friendly and Cost-Effective Solution

Buildings, Journal Year: 2025, Volume and Issue: 15(3), P. 477 - 477

Published: Feb. 3, 2025

To achieve environmental and economic goals in ground improvement, a one-part geopolymer (OPG), synthesized from binary precursors (fly ash [FA] granulated blast furnace slag [GGBFS]) solid activator (solid sodium silicate [NS]), was used to replace ordinary Portland cement (OPC) for stabilizing high-water-content soft clay. The effects of different initial water content (50%, 80%, 100%, 120%) various OPG binder (10%, 20%, 30%, 40%) on the strength development OPG-stabilized clay were investigated through unconfined compressive (UCS) unconsolidated undrained (UU) triaxial tests. Additionally, microstructure evolution distribution pores examined by utilization mercury intrusion porosimetry (MIP) scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS) techniques, respectively. life cycle assessment (LCA) methodology then analyze advantages employing an soil stabilization. It revealed that optimal contingent upon clay, with variations requirements development. Specifically, not demanding early strength, maximum 20% is proposed. Conversely, necessitated rapid gain, escalated increasing which clays contents had corresponding required amounts binder. For ranging 50% recommended 20%. While 100% 120% content, designed suggested be 30% 40%, demonstrated as stabilization reduces costs carbon emissions comparison OPC. present study provides substantial theoretical validation novel stabilize elevated holds promise eco-friendly cost-effective solution improvement.

Language: Английский

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Effect of Early Curing Experiences on Mechanical Properties and Microstructure of ECO-UHPC Prepared by Gold Tailings Sand

Materials, Journal Year: 2025, Volume and Issue: 18(4), P. 842 - 842

Published: Feb. 14, 2025

Fine gold tailings particles generated from mining and refining have the potential to replace high-cost quartz sand in preparation of economical ultra-high-performance concrete (ECO-UHPC) due their large stockpiles, low cost, elimination grinding. In this study, ECO-UHPC was prepared by substituting with tailing (GTS) at substitution rates 0%, 25%, 50%, 75%, 100%. The mechanical properties ECO-UHPC, including its cubic compressive strength, elastic modulus, prismatic as well leaching toxicity, were experimentally analyzed under various early curing experiences such ambient-water (WC), hot-water (HWC), hot-air (HAC), combined (CC). Additionally, scanning electron microscopy (SEM) mercury intrusion porosimetry (MIP) employed interpret macroscopic behavior ECO-UHPC. results indicate that incorporation waste GTS slightly reduces fluidity fresh decreasing it approximately 6.1% a full 100% replacement. As result substitution, strength experiencing WC environment during is reduced 0.7-12.2%. However, thermally cured comparable or even higher than pure quartz-based G0, maximum value occurring G-50. Specifically, G-50 HWC, HAC, CC varies +20.0%, +40.2%, +57.7%, respectively, compared WC. evolution modulus different conditions replacement aligns closely strength. addition, implementation thermal also limits heavy metals best effect observed CC. This because appropriate promotes densification cementitious substance bonding GTS-cementitious material. Overall, study demonstrates feasibility utilizing partial for while maintaining desirable performance environmental safety. findings provide valuable insights into influence regimes on properties, highlighting enhance mitigate risks. Future research should further explore long-term durability GTS-based broader applicability sustainable construction practices.

Language: Английский

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Application of Catalytic H2O2-Mediated NOx Removal Process Leveraging Solid Waste Residues: Exemplified by Copper Slag

Sustainability, Journal Year: 2025, Volume and Issue: 17(6), P. 2469 - 2469

Published: March 11, 2025

In pursuing sustainable environmental solutions, the concept of ‘waste to treasure’ has emerged as a promising approach. this study, new process is proposed combine solid copper slag with hydrogen peroxide (H2O2) remove nitrogen oxides (NOx) from acidic exhaust gases, thus effectively utilizing waste materials. Firstly, different smelting slags were screened determine catalytic potential for peroxide. Subsequently, activity at various stages was thoroughly evaluated and optimized. addition, multifactorial evaluation slow-cooled catalysts removing NOx carried out. Preliminary indications are that iron phase in identified main source sites. The results suggest Fe2+/Fe3+ sites on surface Fe may be crucial improving removal efficiency. reactive oxygen species detected system ·OH, ·O2⁻, 1O2. transformation products, formation pathways, reaction mechanisms NO liquid initially investigated determined. This study provides green path utilization management atmospheric fumes non-ferrous metal industry offers perspectives address challenges industrial processes.

Language: Английский

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Comprehensive Performance Evaluation of Lead–Zinc-Tailing-Based Geopolymer-Stabilized Aggregates

Processes, Journal Year: 2025, Volume and Issue: 13(3), P. 884 - 884

Published: March 17, 2025

As an innovative inorganic cementitious material, geopolymer holds significant application potential in the field of road engineering. Based on theoretical basis industrial solid waste resource utilization and combined with geopolymerization technology, this study investigates feasibility applying lead–zinc-tailing-based geopolymer–stabilized aggregate (LZT-GSA) engineering through systematic mechanical property tests, durability assessment, microstructural characterization. The focuses influence material admixture unconfined compressive strength, splitting tensile resilient modulus, drying shrinkage, freeze–thaw cycle resistance LZT-GSA. experimental results demonstrated that LZT-GSA exhibited excellent properties terms performance durability, which were remarkably better than those conventional cement-stabilized aggregates (CSA). However, incorporation a small amount lead–zinc tailing alone can weaken CSA. shrinkage was slightly higher CSA due to difference intrinsic reaction mechanism between effective cementing wrapping effect gel discrete dramatically improves structural compactness leaching concentration heavy metals is far below requirements environmental protection standards. These research not only provide support for tailings, but also lay technical foundation its practical

Language: Английский

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Sustainable Chromium Remediation: Sorption of Chromium from Leaching Solutions of Refined

Sustainability, Journal Year: 2025, Volume and Issue: 17(6), P. 2726 - 2726

Published: March 19, 2025

Chromium pollution has emerged as a critical environmental concern, prompting extensive research into the chemical and mineralogical properties of refined ferrochrome (RFC) slag, leaching chromium using sulfuric acid, adsorption cations onto natural zeolite. The aim study is to analyze purified slag from Aktobe Ferroalloy Plant its with well effectiveness Shankanai zeolite in acid solution improve waste management industry. Semi-quantitative X-ray analysis reveals that dominant phase RFC olivine (50.7% Ca2SiO4). optimal transition rate (16.67%) occurs dilute H2SO4 (23%) after 145 min leaching, while highest efficiency (18.0–18.5%) achieved at 90 °C duration 145–180 min. cake predominantly divalent state, existing pentahydrate (II) sulfate (CrSO4•5H2O). sorption process was studied obtained slags. by been for first time, influence main technological parameters on degree purification established. It determined chromium-containing ratio zeolite:chromium-containing equal 1:10, heated 35 15 min, it reaches (63.6–69.0%). deposit an effective, inexpensive sorbent cleaning aggressive media, particularly media contaminated acid. diffraction further confirmed both sulfur ions participate process, evidenced microstructural changes zeolite, including pore filling smoothing observed microphotographs. These findings underscore potential efficient cost-effective adsorbent remediation chromium-contaminated solutions following leaching. Its ability adsorb highlights significant applicability cleanup efforts. This contributes sustainability offering environmentally friendly method removal, reducing industrial impact promoting circular economy principles utilizing readily available recyclable adsorbent.

Language: Английский

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Effect of arch foot settlement on soil arching in pile-supported embankments under localized surface loading: Numerical damping spring-based trapdoor tests

Computers and Geotechnics, Journal Year: 2024, Volume and Issue: 169, P. 106252 - 106252

Published: March 21, 2024

Language: Английский

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Rheological, Fresh State, and Strength Characteristics of Alkali-Activated Mortars Incorporating MgO and Carbon Nanoparticles

Materials, Journal Year: 2024, Volume and Issue: 17(23), P. 5931 - 5931

Published: Dec. 4, 2024

This study presents a comprehensive assessment of the fresh state, rheological, and mechanical properties alkali-activated mortars (AAMs) developed by incorporating magnesium oxide (MgO) nanomaterials. A total 24 AAM mixes with varying content MgO, multi-walled carbon nanotube (MWCNT), reduced graphene (rGO) were following one-part dry mix technique using powder-based activators/reagents. The effects types/combinations source materials (binary or ternary)/reagents, MgO (0 to 5%), MWCNT 0.6%), rGO 0.6%) evaluated in terms mini-slump flow, setting times, viscosity, yield stress, compressive strength, ultrasonic pulse velocity (UPV), microstructural properties. results showed that addition finer MgO/nano-fillers produced higher viscosity stress accompanied lower slump flow times. 5% resulted lowest 80 mm, 2-2.5 times reduction initial final about 21% 16%, respectively. Mixes 5-10% whereas for rGO, values noted be 8% higher, on average, than no rGO. All AAMs exhibited shear-thinning behavior. 28-day strength ranged from 37 MPa 49 up 0.3% MWCNT/rGO increased strength. Correlations among such as time, UPV are also described.

Language: Английский

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A Novel Approach for 3D Printing Fiber-Reinforced Mortars

Materials, Journal Year: 2023, Volume and Issue: 16(13), P. 4609 - 4609

Published: June 26, 2023

Three-dimensional printing with cement-based materials is a promising manufacturing technique for civil engineering applications that already allows the design and construction of complex highly customized structures using layer-by-layer deposition approach. The extrusion mechanism one most expensive parts 3D printer. Also, low-scale printers, based on shape extruder geometry limitation mixing blade, mixture often limited to narrow range due risk layer splitting or blockage. Therefore, there need develop affordable feasible alternatives current design–fabrication–application approach printers. In this paper, various newly designed mixtures fiber-reinforced mortars can be printed only commercially available screw pump are analyzed their fresh properties mechanical characteristics. results, in terms extrudability, buildability, flowability, flexural compressive strengths, highlight potential technology constructing high strength durability. reduced facility requirements enable made more applications. With further innovations come future, method these extended sustainable economically single-family housing units.

Language: Английский

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