250 results found
Jiang C, Ramteke DD, Li J, et al., 2023, Preparation and characterization of binary Mg-silicate glasses via Sol-Gel route, Journal of Non-Crystalline Solids, Vol: 606, ISSN: 0022-3093
Sol-gel processing allows synthesis of low-energy glasses. In this work, binary magnesium silicate glasses with various MgO contents are synthesized using a modified sol-gel route. TGA and XRD analyses indicate that amorphous glasses with up to 50 mol% MgO can be obtained at 500°C. The reactivity of the glasses is evaluated to assess the use of the sol-gel technique in the large-scale synthesis of alternative cementitious materials. Reactivity tests show that, as MgO content increases, reactivity of glasses increases, reaches an optimum and then declines. This trend doesn't agree with the theoretical one estimated by NBO/T value, which is generally used for the evaluation of glass reactivity. Mg2+ ions play a role as the network modifier when first introduced to silicate glasses. This leads to the depolymerization of the networks, causing an increase in reactivity. Then the magnesium partly behaves as a network former, bonding with oxygens to form MgOx polyhedron when there are insufficient primary glass-forming oxide SiO2, resulting in the polymerization of networks, hence the decrease in reactivity.
Kia A, Wong HS, Cheeseman CR, 2022, Freeze–thaw durability of conventional and novel permeable pavement replacement, Journal of Transportation Engineering Part B-Pavements, Vol: 148, ISSN: 2573-5438
Permeable concrete pavements are becoming more common as a stormwater management system to mitigate urban flooding. However, they have several well-defined drawbacks including low permeability, high clogging potential, and low strength and durability, notably in cold climates exposed to freezing and thawing. A new generation of high-strength clogging-resistant permeable pavement replacement (CRP) has been developed, through extensive laboratory work, to address these shortcomings and advance the field of permeable pavements. This paper reports on new advances in permeable pavement systems and the performance of a range of conventional permeable concrete and the developed novel CRP (both prepared using Portland cement) of varying porosity exposed to freeze–thaw cycles. This will allow performance evaluations of both systems in a cold climate. The tests involved exposing samples to temperatures varying from −20°C to +20°C and measuring changes in mass, area, compressive strength, and ultrasonic pulse velocity after each cycle. These new results show that CRP is highly resistant to degradation caused by freeze–thaw cycles compared to conventional permeable concrete, reducing maintenance requirements and improving service life. This study presents the first high-strength clogging-resistant permeable pavement replacement that is durable under frost action, these findings will support and enable wider use of permeable pavements in cold regions.
Ayati B, Newport D, Wong H, et al., 2022, Acid activated smectite clay as pozzolanic supplementary cementitious material, Cement and Concrete Research, Vol: 162, Pages: 1-8, ISSN: 0008-8846
This research has investigated the structural changes and pozzolanic activity produced in acid activated smectite clay. The activation treatment used HCl at different concentrations, using different times and at a range of temperatures. X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy were used to determine the acid dissolution mechanism and characterise the activated clay mineral structure. Acid activation causes dehydroxylation of smectite clay, followed by leaching of octahedral cations. This results in the formation of a silica-rich amorphous phase that exhibits substantial pozzolanic activity compared to the same clay sample that had undergone calcining treatment at 850. The optimum sample was activated for 8 h using 5 M HCl at 90 °C. This was 93 % amorphous. Mortar prisms prepared with 25 % replacement of Portland cement by acid activated smectite produced 93 % compressive strength of plain Portland cement mortar.
Chen X, Wang S, Zhou Y, et al., 2022, Improved low-carbon magnesium oxysulfate cement pastes containing boric acid and citric acid, CEMENT & CONCRETE COMPOSITES, Vol: 134, ISSN: 0958-9465
- Author Web Link
- Citations: 2
Ding T, Wong H, Qiao X, et al., 2022, Developing circular concrete: Acid treatment of waste concrete fines, Journal of Cleaner Production, Vol: 365, Pages: 1-8, ISSN: 0959-6526
The development of circular concrete, to enable key components to be extracted and reused, is a key requirement to achieve sustainability in the built environment. Current industry practice for end-of-life concrete is best described as down-cycling because recycled concrete aggregate has limited use, with disposal of the associated crushed concrete fines. Acid treatment of waste concrete is being investigated to allow key concrete components to become circular and, in this work, the effect of acetic acid concentration, liquid/solid (L/S) ratio, reaction time and temperature on the leaching of waste concrete fines is reported. An acid concentration of 0.6 mol/L, an L/S ratio of 7 ml/g, and a reaction time of 6 h at ambient temperature allows clean sand to be extracted from concrete fines. This performs identically to new sand in mortar samples. We show for the first time that the dried and ground silica-rich residue produced by acid leaching has pozzolanic properties comparable to commercially available supplementary cementitious materials (SCM) such as blast furnace slag and coal fly ash. The potential for CO2 sequestration using the Ca2+-rich leached solution to form CaCO3 is calculated. The research shows that acid leaching of concrete fines can produce clean reusable sand, generates a viable SCM and sequester significant amounts of CO2 by forming precipitated calcium carbonate.
Alzeer MIM, Nguyen H, Fabritius T, et al., 2022, On the hydration of synthetic aluminosilicate glass as a sole cement precursor, CEMENT AND CONCRETE RESEARCH, Vol: 159, ISSN: 0008-8846
- Author Web Link
- Citations: 5
Chen X, Zhang T, Cheeseman C, et al., 2022, Production of Rapid-Hardening Magnesium Oxysulfate Cement Containing Boric Acid, Journal of Materials in Civil Engineering, Vol: 34, ISSN: 0899-1561
Alzeer MIM, Cheeseman C, Kinnunen P, 2022, New synthetic glass-based supplementary cementitious materials derived from basalt composition, Journal of Building Engineering, Vol: 46, Pages: 103699-103699, ISSN: 2352-7102
Earl C, Shah IH, Cook S, et al., 2022, Environmental sustainability and supply resillience of cobalt, Sustainability, Vol: 14, Pages: 4124-4124, ISSN: 2071-1050
Cobalt (Co) is an essential metal for the development of energy-transition technologies, decarbonising transportation, achieving several sustainable development goals, and facilitating a future net zero transition. However, the supply of Co is prone to severe fluctuation, disruption, and price instabilities. This review aims to identify the future evolution of Co supply through technologically resilient and environmentally sustainable pathways. The work shows that advances in both primary and secondary sources, Co mining methods and recycling systems are yet to be fully optimised. Moreover, responsible sourcing from both large mines and small artisanal mines will be necessary for a resilient Co supply. Regulatory approaches may increase transparency, support local mining communities, and improve secondary Co recovery. Novel Co supply options, such as deep-sea mining and bio-mining of tailings, are associated with major techno-economic and environmental issues. However, a circular economy, keeping Co in the economic loop for as long as possible, is yet to be optimised at both regional and global scales. To achieve environmental sustainability of Co, economic incentives, regulatory push, and improved public perception are required to drive product innovation and design for circularity. Although the complexity of Co recycling, due to lack of standardisation of design and chemistry in batteries, is an impediment, a sustainable net zero transition using Co will only be possible if a reliable primary supply and a circular secondary supply are established
Jnr AK-L, Galpin R, Manjula S, et al., 2022, Reuse of Waste Plastics in Developing Countries: Properties of Waste Plastic-Sand Composites, WASTE AND BIOMASS VALORIZATION, Vol: 13, Pages: 3821-3834, ISSN: 1877-2641
Kia A, Cheeseman C, Wong H, 2022, High Strength Porous Cement-Based Materials, US20220010500A1
Kia A, Wong HS, Cheeseman CR, 2021, Freeze-Thaw Durability Of Clogging Resistant Permeable Concrete, 12th International Conference on Concrete Pavements, Publisher: International Society for Concrete Pavements
<jats:p>Permeable concrete pavements are one of the most promising flood mitigation strategies. However, they have a number of limitations including low strength, low resistance to clogging and freeze/thaw degradation, limiting their application particularly in cold climates. Through extensive laboratory work, a novel high-strength clogging resistant permeable pavement (CRP) has been developed to address these shortcomings. In this paper, we investigated the freeze-thaw durability performance of a range of conventional permeable concrete and novel CRP. Samples were exposed to repeated freeze-thaw cycles (-20 to +20C) and their mass, ultrasonic pulse velocity (UPV) and compressive strength were evaluated over time. The results show that CRP is highly resistant to freeze-thaw cycles while conventional permeable concrete degrades rapidly. This study demonstrates that CRP is durable under frost action and therefore has the potential to be deployed in harsh wintry conditions.</jats:p>
Kia A, Delens J, Wong H, et al., 2021, Structural and hydrological design of permeable concrete pavements, Case Studies in Construction Materials, Vol: 15, ISSN: 2214-5095
Permeable pavements are used to mitigate urban flooding. However, conventional concrete permeable pavements have low compressive strength and are prone to clogging, which degrades performance and reduces service life. A new type of permeable pavement, high-strength clogging resistant permeable pavement (CRP), has recently been developed that overcomes many limitations of conventional permeable pavements. This paper presents a new design methodology for CRP that takes into account both structural and hydrological considerations. This is used in 12 case studies which compare CRP with conventional permeable pavements. The results highlight several advantages of CRP and demonstrate that CRP with low porosity (∼5%) can cope with severe rainfall run-off volumes. The suitability of using CRP in both light and heavy load bearing applications is demonstrated. The research also shows that the use of CRP allows considerable reductions in pavement depth compared to conventional permeable pavements with reduced material costs.
Zhou Y, Cai G, Cheeseman C, et al., 2021, Sewage sludge ash-incorporated stabilisation/solidification for recycling and remediation of marine sediments, JOURNAL OF ENVIRONMENTAL MANAGEMENT, Vol: 301, ISSN: 0301-4797
- Author Web Link
- Citations: 7
Alzeer MIM, Nguyen H, Cheeseman C, et al., 2021, Alkali-Activation of synthetic aluminosilicate glass with basaltic composition, Frontiers in Chemistry, Vol: 9, ISSN: 2296-2646
Alkali-activated materials (AAMs) are a potential alternative to Portland cement because they can have high strength, good durability and low environmental impact. This paper reports on the structural and mechanical characteristics of aluminosilicate glass with basalt-like compositions, as a feedstock for AAMs. The alkali-activation kinetics, microstructure, and mechanical performance of the alkali activated glass were investigated. The results show that AAMs prepared from basalt glass have high compressive strength (reaching up to 90 MPa after 7 days of hydration) compared to those made using granulated blast furnace slag (GBFS). In addition, calorimetry data show that the hydrolysis of the developed glass and subsequent polymerization of the reaction product occur at a faster rate compared to GBFS. Furthermore, the obtained results show that the alkali activation of the developed glass formed sodium aluminosilicate hydrate (N-A-S-H) intermixed with Ca aluminosilicate hydrate gel (C-A-S-H), while the alkali activation of GBFS resulted in predominantly C-A-S-H gel. The developed glass can be formed from carbonate-free and abundant natural resources such as basalt rocks or mixtures of silicate minerals. Therefore, the glass reported herein has high potential as a new feedstock of AAMs.
Zhang T, Zhou Z, Li M, et al., 2021, Effect of hydrated magnesium carbonate grown in situ on the property of MgO-activated reactive SiO2 mortars, JOURNAL OF SUSTAINABLE CEMENT-BASED MATERIALS, Vol: 11, Pages: 286-296, ISSN: 2165-0373
- Author Web Link
- Citations: 1
Wu C, Chen C, Cheeseman C, 2021, Size Effects on the Mechanical Properties of 3D Printed Plaster and PLA Parts, JOURNAL OF MATERIALS IN CIVIL ENGINEERING, Vol: 33, ISSN: 0899-1561
- Author Web Link
- Citations: 4
Zhou Y, Lu J, Li J, et al., 2021, Effect of NaCl and MgCl2 on the hydration of lime-pozzolan blend by recycling sewage sludge ash, JOURNAL OF CLEANER PRODUCTION, Vol: 313, ISSN: 0959-6526
- Author Web Link
- Citations: 3
Zhou Y-F, Lu J-X, Li J-S, et al., 2021, Hydration, mechanical properties and microstructure of lime-pozzolana pastes by recycling waste sludge ash under marine environment, JOURNAL OF CLEANER PRODUCTION, Vol: 310, ISSN: 0959-6526
- Author Web Link
- Citations: 2
Auwerter LC-C, Cheeseman C, Templeton M, et al., 2021, Quantifying the durability of a friction-reducing surface with recoverable super-hydrophobicity, Journal of Hydraulic Engineering, Vol: 147, Pages: 1-10, ISSN: 0733-9429
The durability of superhydrophobic surfaces in fully immersed conditions is a major obstacle to their application in engineering applications. We perform an experimental study to measure the friction factor fd as a function of time for a new superhydrophobic surface that is capable of recovering the Cassie-Baxter wetting state. Values of fd were obtained by measuring the pressure drop and volume flux of a turbulent water flow in a 1.5 m long duct containing one superhydrophobic wall. The Reynolds number of the flow was approximately 4.5×104 for all experiments. Reductions in fd were 29%–36% relative to a hydraulically smooth surface. The Cassie-Baxter state could be recovered by blowing air through the porous surface for 10 min. The durability of the drag-reduction, as quantified by the relaxation time T in which the surface loses its superhydrophobic characteristics, were measured to be between 10 and 60 min depending on the initial head. The relaxation time T was highly dependent on the pressure difference across the surface. In contrast to models based on Darcy flow through a porous medium, the study indicates that there seems to be a critical pressure difference beyond which the Cassie-Baxter state cannot be sustained for the material under consideration.
Yio M, Yue X, Ji R, et al., 2021, Production of foamed glass-ceramics using furnace bottom ash and glass, Ceramics International, Vol: 47, Pages: 8697-8706, ISSN: 0272-8842
This research has produced foamed glass-ceramics from coal fired power station furnace bottom ash (FBA) and soda-lime-silica glass. The as-received FBA was wet milled with different additions of glass. The resultant slurry was dried and formed into a powder. The powder was pressed and sintered at a range of temperatures with additions of a fluxing agent (sodium tetraborate decahydrate), a bubble stabilising additive (tri-sodium phosphate) and a bloating agent (calcium carbonate) and this produced foamed FBA-glass-ceramics. The effect of glass content and sintering temperature on the properties of the sintered ceramic foams are reported. A range of potential applications including thermal insulation and biological filters for water and wastewater treatment are discussed. The research demonstrates that it is possible to engineer the properties of FBA derived glass-ceramic foams by careful control of the composition and processing conditions in order to transform a problematic waste into commercially interesting materials.
Guan Y, Hu Z, Zhang Z, et al., 2021, Effect of hydromagnesite addition on the properties and water resistance of magnesium oxysulfate (MOS) cement, CEMENT AND CONCRETE RESEARCH, Vol: 143, ISSN: 0008-8846
- Author Web Link
- Citations: 17
Scott A, Oze C, Shah V, et al., 2021, Transformation of abundant magnesium silicate minerals for enhanced CO2 sequestration, COMMUNICATIONS EARTH & ENVIRONMENT, Vol: 2
- Author Web Link
- Citations: 14
Dieckmann E, Onsiong R, Nagy B, et al., 2021, Valorization of waste feathers in the production of new thermal insulation materials, Waste and Biomass Valorization, Vol: 12, Pages: 1119-1131, ISSN: 1877-2641
Poultry has become the primary source of dietary protein consumed globally and as a result the by-product feathers are an increasingly problematic industrial waste. Developing a circular economy for feathers is, therefore, an important research area that provides an opportunity to make use of the unique combination of properties of this abundant natural material. This paper reports on the thermal properties of novel feather-based thermal insulation materials. Waste feathers were collected, cleaned and processed into fibres, which were then used to form air-laid nonwoven materials. These have a high fibre content and exploit the excellent natural thermal insulation properties of feathers. The performance of the novel materials developed are tested in order to outline the influence of temperature and density on thermal conductivity and dynamic water sorption. Results are compared to a range of commercially available thermal insulation materials for buildings manufactured from denim, hemp, sheep wool, PET and mineral wool. It was found that air laid feather-fibre fabrics have comparable performance to other fibrous materials and have a thermal conductivity of 0.033 W/(m K) for samples with a density of 59 kg/m3. This is due to the low thermal conductivity of feather fibres and the void structure formed by air-laid processing that effectively traps air. These materials additionally offer improved sustainability credentials as they are derived from a readily available waste that is generally considered to be unavoidable. The paper concludes by highlighting the significant technical and commercial barriers that exist to using waste feathers in thermal insulation products and suggests areas for further research that can exploit the unique properties of feathers.
Zhou Y, Lu J, Li J, et al., 2021, Influence of seawater on the mechanical and microstructural properties of lime-incineration sewage sludge ash pastes, CONSTRUCTION AND BUILDING MATERIALS, Vol: 278, ISSN: 0950-0618
- Author Web Link
- Citations: 2
Zhang T, Li T, Zhou Z, et al., 2020, A novel magnesium hydroxide sulfate hydrate whisker-reinforced magnesium silicate hydrate composites, Composites Part B: Engineering, Vol: 198, ISSN: 0961-9526
Magnesium hydroxide sulfate hydrate (MHSH) whiskers are used to reinforce magnesium silicate hydrate (M-S-H) cement mortars as novel microfibrous materials because of their similar pH. The microstructure, mechanical performance, and reinforcement mechanism were investigated, and the results showed that the addition of between 1 and 5 wt% MHSH whiskers improved the compressive and flexural strengths of M-S-H cement mortars. The optimal compressive and flexural strengths were obtained at MHSH whisker contents between 3 and 4 wt%. The MHSH whiskers had a limited effect on the toughness of M-S-H cement, and mortars reinforced with MHSH whiskers exhibited brittle failure due to the small size of MHSH whiskers and low fiber bridging traction. Scanning electron microscopy (SEM) revealed that the microscale reinforcement mechanism of MHSH whiskers involved whisker pullout, crack deflection, whisker-cement coalition pullout, and whisker fracture. These mechanisms helped dissipate energy and optimize the stress distribution and transfer, which were crucial to improving the flexural strength. The SEM images revealed the rough and grooved surfaces of MHSH whiskers, and X-ray photoelectron spectroscopy (XPS) showed the presence of polar functional groups on the surface which resulted in the adhesion of M-S-H gel on MHSH whiskers due to good interfacial bonding. The mercury intrusion porosimetry (MIP) results indicated that the addition of MHSH whiskers reduced the porosity of M-S-H cement mortars, which also contributed to the increased compressive strength.
Vilchez V, Dieckmann E, Tammelin T, et al., 2020, Upcycling Poultry Feathers with (Nano)cellulose: Sustainable Composites Derived from Nonwoven Whole Feather Preforms, ACS Sustainable Chemistry & Engineering, Vol: 8, Pages: 14263-14267, ISSN: 2168-0485
Ferraro A, Colangelo F, Farina I, et al., 2020, Cold-bonding process for treatment and reuse of waste materials: Technical designs and applications of pelletized products, Critical Reviews in Environmental Science and Technology, Vol: 51, Pages: 2197-2231, ISSN: 1064-3389
This work provides a comprehensive review of research on the cold-bonding pelletization process used to produce lightweight aggregates (LWAs) using waste materials, to valorize the waste and, at the same time, minimize risks related to disposal. Research investigating various aspects of the cold-bonding process highlight: i) feasible mix-designs for pellet production; ii) the most relevant operating parameters affecting the process; and iii) the potential applications of the LWAs produced. The analysis gives a wide overview of the fundamental key-points that control the cold-bonding process. Data comparison provides a useful way to identify the optimal process conditions to allow development of optimum products. This involves the selection of the correct mix-design, including suitable binders and potential additives, and the selection of appropriate operating conditions, which are a function of the waste investigated, and/or waste mix characteristics. The review proposes an optimized approach to experimental studies on cold-bonding processes that has potential to enhance future process performance. Moreover, the present work provides a complete framework useful for decision-making for both manufacturers and researchers working to use this promising technique.
Zhao Y, Dieckmann E, Cheeseman C, 2020, Low-temperature thermal insulation materials with high impact resistance made from feather-fibres, Materials Letters: X, Vol: 6, Pages: 1-5, ISSN: 2590-1508
Thermal insulation materials typically used in low-temperature applications such as pipelines for transporting liquid natural gas can become brittle and are therefore susceptible to impact damage. New feather-fibre biomaterials developed in this work have extremely low thermal conductivity but retain high impact resistance at low-temperatures. The experiments reported demonstrate the improved impact resistance of feather fibre biomaterials compared to foamed nitrile rubber. The microstructural characteristics of feather-fibre biomaterials that allow them to be used as impact resistant thermal insulation at low-temperatures are discussed.
Zhou Y-F, Li J-S, Lu J-X, et al., 2020, Sewage sludge ash: A comparative evaluation with fly ash for potential use as lime-pozzolan binders, Construction and Building Materials, Vol: 242, Pages: 1-10, ISSN: 0950-0618
The disposal of sewage sludge ash (SSA) has become an environmental issue due to the limited available landfill space. This study aims at applying the finely-ground sewage sludge ash (FSSA) with quicklime and hydrated lime to develop a new type of lime-pozzolan system and study the effects of different types of lime on the mechanical properties of the systems. A traditional pozzolanic material (i.e. coal fly ash (FA)) was also used to compare with the FSSA. Multiple techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) were used to assess the hydration kinetics and microscopic characteristics of the lime-pozzolan systems. The results showed that the quicklime system exhibited lower strength than the hydrated lime system, which was due to its lower reaction degree with the FSSA and the higher porosity caused by the expansion during the vigorous hydration reaction of quicklime. Compared to FA, the FSSA attained higher strength for the whole curing period (up to 90 d) in the lime system due to the highly porous nature of FSSA leading to a lower effective water to binder ratio. However, in the hydrated lime system, due to the higher overall pozzolanic activity of FA, its long-term strength values gradually improved. Besides, calcium phosphate hydrate crystals were detected by XRD in the FSSA; while some clinotobermorite was found in the FA both from XRD and SEM, which might govern the strength gain in the lime-FA system. Overall, the application of FSSA as a pozzolan in the lime-pozzolan system could be a promising option to both relieve the waste disposal pressure and provide a potential sustainable construction material.
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