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Functional Cement-Based Composites for Civil Engineering

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Construction and Building Materials".

Deadline for manuscript submissions: closed (20 February 2023) | Viewed by 23723

Special Issue Editor


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Guest Editor
Faculty of Computing, School of Engineering, Engineering and Science, University of South Wales, Pontypridd CF37 1DL, UK
Interests: low-carbon technology; sustainability; cement; concrete; bricks; blocks; geopolymers; soil stabilization; suppression of expansion; freezing and thawing; waste utilization; microstructural analysis; life cycle inventory; ground granulated blastfurnace slag; pulverized fuel ash; silica fume
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Special Issue Information

Dear Colleagues,

The production of cement-based construction and building is set to continue increasing as demand worldwide continues to increase, especially where emerging economies need cement-based materials for housing and infrastructure. In the context of increased regulations to reduce the carbon footprint of the construction industry and to limit greenhouse gas emission associated with cement production, this Special Issue will bring together cutting-edge and economically viable new construction and building materials made from alternative cement replacement materials, even though construction cost and technical barriers, such as insufficient durability data and differentiation for different applications, still hinder the global promotion and utilization of new sustainable construction and building materials development. Within the scope of this research topic, emphasis will be focused on fundamental, experimental, numerical, validation, and application research, inducing proven results in state-of-the-art solutions for sustainable construction. Various single-focused approaches or multidisciplinary combinations are also expected to add to the Special Issue. In general, traditionally, the most widely used construction and building materials are produced with Portland cement (PC); however, there have been some sustainability concerns as it is expensive to make and transport, and the manufacturing process is environmentally destructive, accounting for about 8% of global CO2 emissions. This has led to the use of several new sustainable alternative materials for PC replacement with significant benefits, to mitigate the environmental damage caused by PC. This Special Issue will also bring together techniques and concepts from various distinct works, to examine, explore, and critically engage with issues and advances in sustainable construction and building materials, that can provide several environmental benefits but also can lead to cost-effective products. The papers collected in this Special Issue can help researchers and practicing engineers, construction and building material scientists, low carbon and sustainability practitioners to find more advanced techniques and alternative approaches towards sustainable construction and building material development.

Dr. Jonathan Oti
Guest Editor

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Keywords

  • sustainable materials
  • building materials
  • durability
  • recycled materials
  • cement
  • concrete
  • stabilisation
  • life-cycle assessment
  • bricks
  • block
  • mortar
  • geo-polymer
  • Steel
  • Timber
  • green building materials
  • eco-friendly materials
  • nano- and fiber composites
  • ceramics
  • limes
  • PFA
  • GGBS

Published Papers (13 papers)

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Research

17 pages, 9656 KiB  
Article
Evaluation of the Effect of Binary Fly Ash-Lime Mixture on the Bearing Capacity of Natural Soils: A Comparison with Two Conventional Stabilizers Lime and Portland Cement
by Yhan P. Arias-Jaramillo, Diana Gómez-Cano, Gloria I. Carvajal, César A. Hidalgo and Fredy Muñoz
Materials 2023, 16(11), 3996; https://doi.org/10.3390/ma16113996 - 26 May 2023
Cited by 3 | Viewed by 1130
Abstract
This study evaluates a binary mixture of fly ash and lime as a stabilizer for natural soils. A comparative analysis was performed on the effect on the bearing capacity of silty, sandy and clayey soils after the addition of lime and ordinary Portland [...] Read more.
This study evaluates a binary mixture of fly ash and lime as a stabilizer for natural soils. A comparative analysis was performed on the effect on the bearing capacity of silty, sandy and clayey soils after the addition of lime and ordinary Portland cement as conventional stabilizers, and a non-conventional product of a binary mixture of fly ash and Ca(OH)2 called FLM. Laboratory tests were carried out to evaluate the effect of additions on the bearing capacity of stabilized soils by unconfined compressive strength (UCS). In addition, a mineralogical analysis to validate the presence of cementitious phases due to chemical reactions with FLM was performed. The highest UCS values were found in the soils that required the highest water demand for compaction. Thus, the silty soil added with FLM reached 10 MPa after 28 days of curing, which was in agreement with the analysis of the FLM pastes, where soil moistures higher than 20% showed the best mechanical characteristics. Furthermore, a 120 m long track was built with stabilized soil to evaluate its structural behavior for 10 months. An increase of 200% in the resilient modulus of the FLM-stabilized soils was identified, and a decrease of up to 50% in the roughness index of the FLM, lime (L) and Ordinary Portland Cement (OPC)-stabilized soils compared to the soil without addition, resulting in more functional surfaces. Full article
(This article belongs to the Special Issue Functional Cement-Based Composites for Civil Engineering)
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16 pages, 6289 KiB  
Article
Improvement of Core–Shell Lightweight Aggregate by Modifying the Cement–EPS Interface
by Chaoming Pang, Chunpeng Zhang and Peijuan Li
Materials 2023, 16(7), 2827; https://doi.org/10.3390/ma16072827 - 02 Apr 2023
Cited by 1 | Viewed by 1240
Abstract
To improve the interfacial compatibility between cement matrix and expanded polystyrene (EPS) in core–shell lightweight aggregates (CSLA), the effects of sodium silicate, polyvinyl acetate (PVA) emulsion, vinyl acetate–ethylene (VAE) emulsion, acrylic acid, and acetic acid on the cement–EPS interface were investigated. The density [...] Read more.
To improve the interfacial compatibility between cement matrix and expanded polystyrene (EPS) in core–shell lightweight aggregates (CSLA), the effects of sodium silicate, polyvinyl acetate (PVA) emulsion, vinyl acetate–ethylene (VAE) emulsion, acrylic acid, and acetic acid on the cement–EPS interface were investigated. The density of the interface was studied by scanning electron microscopy (SEM), and the effect of interfacial agents on the hydration process of cement was studied by the heat of hydration and induction resistivity. The macroscopic properties of the interface of the CSLA were characterized by the “leak-white” rate, drop resistance, and numerical crushing strength. The results show that the sodium silicate densifies the interface by generating hydration products on the EPS surface. At the same time, organic acid enhances the interfacial properties of EPS and cement by increasing the surface roughness, and allowing hydration products to grow in the surface micropores. In terms of the cement hydration process, both interfacial agents delay the cement hydration. Above all, with comprehensive interface properties, “leak-white” rate, and mechanical properties, VAE emulsion and sodium silicate can achieve the best performance with a final crushing resistance of 5.7 MPa, which had a 46% increase compared with the reference group. Full article
(This article belongs to the Special Issue Functional Cement-Based Composites for Civil Engineering)
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15 pages, 7581 KiB  
Article
Physico-Mechanical Evaluation of Geopolymer Concrete Activated by Sodium Hydroxide and Silica Fume-Synthesised Sodium Silicate Solution
by Blessing O. Adeleke, John M. Kinuthia, Jonathan Oti and Mansour Ebailila
Materials 2023, 16(6), 2400; https://doi.org/10.3390/ma16062400 - 17 Mar 2023
Cited by 7 | Viewed by 1796
Abstract
Commercial sodium hydroxide (NaOH) and sodium silicate (SS) have remained two of the leading alkaline activators widely used in producing geopolymer concrete, despite some identified negatives regarding their availability and additional CO2 emissions relating to the overall manufacturing process. This study reports [...] Read more.
Commercial sodium hydroxide (NaOH) and sodium silicate (SS) have remained two of the leading alkaline activators widely used in producing geopolymer concrete, despite some identified negatives regarding their availability and additional CO2 emissions relating to the overall manufacturing process. This study reports the viability of developing geopolymer concrete using a laboratory-synthesised silica fume (SF)-derived SS solution in combination with NaOH at a molarity of 10M as an alternative binary alkali-alkaline activator to Ground Granulated Blast Furnace slag (GGBS). The use of SF in the development of geoolymer activators will pave the way for the quality usage of other high-silica content by-products from nature, industry, and agriculture. In the currently reported proof of concept, four geopolymer concrete batches were produced using different alkaline activator/precursor-A/P ratios (0.5 and 0.9) and SS to NaOH-SS/SH volume ratios (0.8/1.2 and 1.2/0.8), to establish the impact on the engineering performance. Two controls were adopted for ordinary and geopolymer concrete mixes. The engineering performance was assessed using slump and compaction index (CI) tests, while the Unconfined Compressive Strength (UCS) and tensile splitting (TS) tests were measured at different curing ages in accordance with their appropriate standards. The results indicated a reduction in slump values as the A/P ratio decreased, while the CI values showed a reversal of the identified trend in slump. Consequently, mix GC2 attained the highest UCS strength gain (62.6 MPa), displaying the superiority of the alkali activation and polymerisation process over the CSH gel. Furthermore, the impact of A/P variation on the UCS was more pronounced than SS/SH due to its vital contribution to the overall geopolymerisation process. Full article
(This article belongs to the Special Issue Functional Cement-Based Composites for Civil Engineering)
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12 pages, 1260 KiB  
Article
Effects of Mellowing Practice on the Strength and Swelling Properties of Road Construction Materials: Case of Sulphate-Bearing Clay Soils Stabilised with Lime-Silica Fume Blended Binder
by Qusai Al-Waked, John M. Kinuthia, Blessing O. Adeleke, Jonathan Oti and Ahmed Khalifa
Materials 2023, 16(6), 2187; https://doi.org/10.3390/ma16062187 - 09 Mar 2023
Viewed by 1202
Abstract
The main thrust of this research was to establish any benefits of mellowing, and the optimal moisture content (OMC) for compacting mellowed sulphate-bearing clay soil undergoing the stabilization process. Two three-day mellowing regimes were carried out, prior to final compaction, at different initial [...] Read more.
The main thrust of this research was to establish any benefits of mellowing, and the optimal moisture content (OMC) for compacting mellowed sulphate-bearing clay soil undergoing the stabilization process. Two three-day mellowing regimes were carried out, prior to final compaction, at different initial moisture contents of 30% or 40% OMC. The unmellowed specimens were compacted immediately after mixing with the blended stabilizers. A blend of quicklime (L) with a sustainable by-product, silica fume (SF), at a 1:1 ratio (2%L–2%SF) was used. Linear expansion and unconfined compressive strength (UCS) tests were carried out to evaluate the benefits of mellowing. The test results suggested that the mellowed test specimens achieved better UCS and swelling properties compared to the unmellowed specimens. Mellowing at 1.2 OMC produced better strength performance than at 1.4 OMC, whereas mellowed specimens at 1.4 OMC showed better resistance to linear expansion compared to 1.2 OMC. The research findings suggested that optimal performance was achieved by mellowing at the higher initial moisture condition of 40% OMC and compacting the materials at the lower moisture condition of 1.2 OMC. Full article
(This article belongs to the Special Issue Functional Cement-Based Composites for Civil Engineering)
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15 pages, 5625 KiB  
Article
Ignimbrites Related to Neogene Volcanism in the Southeast of the Iberian Peninsula: An Experimental Study to Establish Their Pozzolanic Character
by Domingo A. Martín, Jorge L. Costafreda, Leticia Presa, Elena Crespo, José Luis Parra, Beatriz Astudillo and Miguel Ángel Sanjuán
Materials 2023, 16(4), 1546; https://doi.org/10.3390/ma16041546 - 13 Feb 2023
Cited by 3 | Viewed by 1232
Abstract
The speed at which climate change is happening is leading to a demand for new pozzolanic materials that improve the quality of cements and, at the same time, limit the emission of greenhouse gases into the atmosphere. The main objective of this work [...] Read more.
The speed at which climate change is happening is leading to a demand for new pozzolanic materials that improve the quality of cements and, at the same time, limit the emission of greenhouse gases into the atmosphere. The main objective of this work is the detailed characterization of an ignimbrite sample (IGNS) to demonstrate its effectiveness as a natural pozzolan. To meet this objective, a series of tests were carried out. In the first stage, mineral and chemical analyses were performed, such as petrographic analysis by thin section (TSP), X-ray diffraction (XRD), oriented aggregate (OA), scanning electron microscopy (SEM) and X-ray fluorescence (XRF). In the second stage, the following technical tests were carried out: chemical quality analysis (QCA), pozzolanicity test (PT) and mechanical compressive strength (MS) at 7, 28 and 90 days, using mortar specimens with ignimbrite/cement formulation (IGNS/PC): 10, 25 and 40% to establish the pozzolanic nature of the ignimbrite. The results of the mineral and chemical analyses showed that the sample has a complex mineralogical constitution, consisting of biotite mica, potassium feldspar, plagioclase, smectite (montmorillonite), quartz, volcanic glass, iron, titanium and manganese oxides, chlorite and chlorapatite. On the other hand, the technological tests revealed the pozzolanic nature of the sample, as well as visible increases in the mechanical compressive strengths in the three proportions, the most effective being IGNS/PC:10% and IGNS/PC:25% at 7, 28 and 90 days of setting. The results obtained could be applied in the formulation of new pozzolanic cements with ignimbrite as a natural pozzolanic aggregate. Full article
(This article belongs to the Special Issue Functional Cement-Based Composites for Civil Engineering)
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16 pages, 1857 KiB  
Article
Chloride Diffusion in Concrete Made with Coal Fly Ash Ternary and Ground Granulated Blast-Furnace Slag Portland Cements
by Miguel Ángel Sanjuán, Rosa Abnelia Rivera, Domingo Alfonso Martín and Esteban Estévez
Materials 2022, 15(24), 8914; https://doi.org/10.3390/ma15248914 - 13 Dec 2022
Cited by 8 | Viewed by 1336
Abstract
Ternary Portland cement usage with a high amount of cement constituents different from clinker can afford great climate change advantages by lowering the Portland cement clinker content in the final product. This will contribute to cutting greenhouse gas emissions to close to zero [...] Read more.
Ternary Portland cement usage with a high amount of cement constituents different from clinker can afford great climate change advantages by lowering the Portland cement clinker content in the final product. This will contribute to cutting greenhouse gas emissions to close to zero by 2050. Such ternary Portland cements can be composed of different amounts of ground granulated blast-furnace slag (GBFS), coal fly ash (CFA), and clinker (K). Cements made with GGBFS, or CFA boast pozzolanic characteristics. Therefore, they would improve both the concrete compressive strength at later ages and durability. The 28- and 90-days mechanical strength test, non-steady state chloride migration test, described in NT BUILD 492, and natural chloride diffusion test (NT BUILD 443) were performed in concrete. Ternary cements made with GBFS and/or CFA presented better chloride diffusion resistance than concrete made with plain Portland cements. Furthermore, the development of compressive strength was delayed. The service life study was developed for concretes made with ternary cements with regard to the chloride penetration case. Full article
(This article belongs to the Special Issue Functional Cement-Based Composites for Civil Engineering)
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19 pages, 5370 KiB  
Article
L-Ascorbic Acid as an Efficient Green Corrosion Inhibitor of Steel Rebars in Chloride Contaminated Cement Mortar
by Cristina Argiz, Celia Arroyo, Astrid Bravo, Amparo Moragues, Carmen Andrade and Fabio Bolzoni
Materials 2022, 15(22), 8005; https://doi.org/10.3390/ma15228005 - 12 Nov 2022
Cited by 3 | Viewed by 1799
Abstract
Corrosion of reinforcement is a major problem regarding concrete durability. In new structures the corrosion onset can be delayed if additional protection methods are provided as is the case for the addition of corrosion inhibitors in the concrete mix. The main goal of [...] Read more.
Corrosion of reinforcement is a major problem regarding concrete durability. In new structures the corrosion onset can be delayed if additional protection methods are provided as is the case for the addition of corrosion inhibitors in the concrete mix. The main goal of this paper is the evaluation of the effect of the ascorbic acid (AA) as a green steel corrosion inhibitor in cement mortars contaminated by chlorides. Concentration levels of ascorbic acid, ranging from 0.5 to 10−3 mol/L, were added to the mixing water. Electrochemical methods, including corrosion potential (Ecorr), linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS), were employed to assess the corrosion rate of the steel embedded in the mortars. The corrosion inhibiting performance of ascorbic acid was compared with that of sodium nitrite. The interaction of the ascorbic acid with the hydrated cement matrix was also evaluated with differential thermal and thermogravimetric analysis (DTA/TG) and pH measurements. The results indicated that, depending on the ascorbic acid concentration, it can be an activator of the corrosion process or an effective corrosion inhibitor in a similar manner to sodium nitrite. A corrosion rate decrease was achieved with concentrations below 10−2 mol/L and the optimum content was 10−3 mol/L. Within this concentration range, the AA does not modify the hydration performance of the cement matrix. Full article
(This article belongs to the Special Issue Functional Cement-Based Composites for Civil Engineering)
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14 pages, 3284 KiB  
Article
Research on Impermeability of Underwater Non-Dispersible Concrete in Saline Soil
by Baolin Guo, Chao Wang, Xianghui Ma, Ruishuang Jiang, Baomin Wang, Jifei Yan and Hang Liu
Materials 2022, 15(22), 7915; https://doi.org/10.3390/ma15227915 - 09 Nov 2022
Cited by 2 | Viewed by 1077
Abstract
The permeability of different strength grades of submerged non-dispersible concrete with different granulated slag admixtures in a saline soil environment simulated by different erosion solutions was investigated. The variation patterns of the chloride ion diffusion coefficient and pore characteristics were tested using NEL [...] Read more.
The permeability of different strength grades of submerged non-dispersible concrete with different granulated slag admixtures in a saline soil environment simulated by different erosion solutions was investigated. The variation patterns of the chloride ion diffusion coefficient and pore characteristics were tested using NEL and MIP. The microscopic morphology of the specimens in different erosion environments and with slag doping was observed using SEM. The results showed that the impermeability of concrete in sulfate and complex salt environments was significantly reduced. The resistance of concrete to chloride ion penetration increased with the increase in strength grade, and the Cl− diffusion coefficient of C35 was 5–30% lower than those of C30 and C25 underwater non-dispersible concrete at 360 d. Meanwhile, the admixture of granulated blast-furnace slag optimized the pore size distribution and improved the matrix compactness and permeability. Full article
(This article belongs to the Special Issue Functional Cement-Based Composites for Civil Engineering)
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14 pages, 1665 KiB  
Article
Role of Gypsum Content on the Long-Term Performance of Lime-Stabilised Soil
by Mansour Ebailila, John Kinuthia and Jonathan Oti
Materials 2022, 15(15), 5099; https://doi.org/10.3390/ma15155099 - 22 Jul 2022
Cited by 10 | Viewed by 1236
Abstract
The role of gypsum level on the long-term strength and expansion of soil stabilised with different lime contents is not well understood. This research, therefore, studied the effect of varying gypsum concentrations of 0, 3, 6, and 9 wt% (equivalent to the sulfate [...] Read more.
The role of gypsum level on the long-term strength and expansion of soil stabilised with different lime contents is not well understood. This research, therefore, studied the effect of varying gypsum concentrations of 0, 3, 6, and 9 wt% (equivalent to the sulfate contents of 0, 1.4, 2.8, and 4.2%, respectively) on the performance of sulfate soil stabilised with two lime levels (4 and 6 wt%). This was carried out to establish the threshold level of gypsum/lime (G/L) at which the increase in G/L ratio does not affect the performance of lime-stabilised sulfate soil. Both unconfined compressive strength (UCS) and expansion, along with the derivative thermogravimetric (DTG) analysis, were adopted to accomplish the present objective. Accordingly, the result indicated that the strength and expansion were proportional to the lime and sulfate content, of which a G/L ratio of 1.5 was the optimum case scenario for UCS, and at the same time, the worst-case scenario for expansion. This discovery is vital, as it is anticipated to serve as a benchmark for future research related to the design of effective binders for suppressing the sulfate-induced expansion in lime-stabilised gypseous soil. Full article
(This article belongs to the Special Issue Functional Cement-Based Composites for Civil Engineering)
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17 pages, 2475 KiB  
Article
Suppression of Sulfate-Induced Expansion with Lime–Silica Fume Blends
by Mansour Ebailila, John Kinuthia and Jonathan Oti
Materials 2022, 15(8), 2821; https://doi.org/10.3390/ma15082821 - 12 Apr 2022
Cited by 5 | Viewed by 1705
Abstract
Sulfate-induced expansion resulting from the formation of ettringite in sulfate-bearing soil stabilised with calcium-based stabilisers is a problematic issue with technical and economic implications. Thus, this research examines the viability of the co-addition of lime (L) and silica fume (S) at varying binder [...] Read more.
Sulfate-induced expansion resulting from the formation of ettringite in sulfate-bearing soil stabilised with calcium-based stabilisers is a problematic issue with technical and economic implications. Thus, this research examines the viability of the co-addition of lime (L) and silica fume (S) at varying binder dosages (4, 6, and 10 wt%), with a view of establishing the optimum blend of L–S for suppressing the ettringite-induced expansion of artificially high sulfate-dosed soil (kaolinite-K and gypsum-G). To do so, a series of laboratory specimens, designed using different gypsum and lime concentrations, were investigated using unconfined compression strength (UCS), linear expansion, and derivative thermo-gravimetric analysis (DTG) as the main criteria for the examination. The research outcomes indicated that the increasing substitution of L with S induces a gradual reduction on the UCS and linear expansion at binder levels of 4 and 6 wt%, while its usage in a high binder level (10 wt%), can yield an expansion reduction, with no compromise on the UCS performance. Therefore, silica fume has the potential for restricting ettringite formation and suppressing the expansion, of which 3L7S is the optimum blending ratio for suppressing the expansion. Full article
(This article belongs to the Special Issue Functional Cement-Based Composites for Civil Engineering)
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27 pages, 12675 KiB  
Article
Road Pavement Thickness and Construction Depth Optimization Using Treated and Untreated Artificially-Synthesized Expansive Road Subgrade Materials with Varying Plasticity Index
by Samuel Y. O. Amakye, Samuel J. Abbey, Colin A. Booth and Jonathan Oti
Materials 2022, 15(8), 2773; https://doi.org/10.3390/ma15082773 - 09 Apr 2022
Cited by 8 | Viewed by 4111
Abstract
Road pavement thickness and their depth of construction take a chunk of the overall cost of road construction. This has called for a need for reduced road pavement thickness by improving the engineering properties of subgrade such as the California bearing ratio (CBR). [...] Read more.
Road pavement thickness and their depth of construction take a chunk of the overall cost of road construction. This has called for a need for reduced road pavement thickness by improving the engineering properties of subgrade such as the California bearing ratio (CBR). The CBR of road subgrade has been a major determining factor for road pavement thickness, and expansive subgrades generally have a low CBR, resulting in major road defects. In this study, road pavement thickness and construction depth optimization were conducted using the CBR values achieved in this study. Additives proportions of 8% lime and 20% cement were used in expansive subgrade to improve their engineering properties, making them suitable for use in road construction. The study investigated the characteristics, mineral structure, Atterberg limit, compaction, CBR, swell and microstructural properties of expansive subgrade. The results show a reduction in road pavement thickness and a construction depth with an increase in CBR value. All CBR values for treated samples were above 2%, making them usable in road construction. A reduction in swell potential up to 0.04% was observed for treated expansive subgrade. The study concluded that pavement thickness and construction depth can be reduced by enhancing subgrade materials and using cement and lime as binders. Full article
(This article belongs to the Special Issue Functional Cement-Based Composites for Civil Engineering)
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21 pages, 23587 KiB  
Article
Reutilizing Waste Iron Tailing Powders as Filler in Mortar to Realize Cement Reduction and Strength Enhancement
by Liyun Cui, Peiyuan Chen, Liang Wang, Ying Xu and Hao Wang
Materials 2022, 15(2), 541; https://doi.org/10.3390/ma15020541 - 11 Jan 2022
Cited by 9 | Viewed by 1370
Abstract
Recently, the massive accumulation of waste iron tailings powder (WITP) has resulted in significant environmental pollution. To solve this problem, this paper proposes an original mortar replacement (M) method to reuse waste solids and reduce cement consumption. In the experiment, the author employed [...] Read more.
Recently, the massive accumulation of waste iron tailings powder (WITP) has resulted in significant environmental pollution. To solve this problem, this paper proposes an original mortar replacement (M) method to reuse waste solids and reduce cement consumption. In the experiment, the author employed an M method which replaces water, cement, and sand with WITP under constant water/cement and found that the strength development can be significantly improved. Specifically, a mortar with 20% WITP replacement can obtain a 30.95% improvement in strength development. To study the internal mechanism, we performed experiments such as thermogravimetric analysis (TGA), mercury intrusion porosimetry (MIP), and SEM. The results demonstrate that the nucleation effect and pozzolanic effect of WITP can help promote cement hydration, and MIP reveals that WITP can effectively optimize pore structure. In addition, 1 kg 20% WITP mortar reduced cement consumption by 20%, which saves 19.98% of the economic cost. Comprehensively, our approach achieves the effective utilization of WITP and provides a favorable reference for practical engineering. Full article
(This article belongs to the Special Issue Functional Cement-Based Composites for Civil Engineering)
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15 pages, 6509 KiB  
Article
Effects of Thermal Conductive Materials on the Freeze-Thaw Resistance of Concrete
by Byeong-Hun Woo, Dong-Ho Yoo, Seong-Soo Kim, Jeong-Bae Lee, Jae-Suk Ryou and Hong-Gi Kim
Materials 2021, 14(15), 4063; https://doi.org/10.3390/ma14154063 - 21 Jul 2021
Cited by 12 | Viewed by 2497
Abstract
To solve the problem of black ice, many studies are being carried out. The key in recent days is enhancing the thermal conductivity of concrete. In this study, to improve the thermal conductivity, silicon carbide was used to substitute 50% and 100% of [...] Read more.
To solve the problem of black ice, many studies are being carried out. The key in recent days is enhancing the thermal conductivity of concrete. In this study, to improve the thermal conductivity, silicon carbide was used to substitute 50% and 100% of the fine aggregate. In addition, steel fiber is not only for enhancing the mechanical properties but could enhance thermal conductive material. Hence, the arched-type steel fiber was used up to a 1% volume fraction in this study. Furthermore, graphite was used for 5% of the volume fraction for enhancing the thermal conductivity. However, thermal damage would occur due to the difference in thermal conductivity between materials. Therefore, the thermal durability must be verified first. The target application of the concrete in this study was its use as road paving material. To evaluate the thermal durability, freeze–thaw and rapid cyclic thermal attacks were performed. The thermal conductivity of the specimens was increased with the increase in thermal conductive materials. Graphite has already been reported to have a negative effect on mechanical properties, and the results showed that this was the case. However, the steel fiber compensated for the negative effect of graphite, and the silicon carbide provided a filler effect. Graphite also had a negative effect on the freeze–thaw and rapid cyclic thermal attack, but the steel fiber compensated for the reduction in thermal durability. The silicon carbide also helped to improve the thermal durability in the same way as steel fiber. Comprehensively, the steel fiber enhanced all of the properties of the tests. Using 100% silicon carbide was considered the acceptable range, but 50% of silicon carbide was the best. Graphite decreased all the properties except for the thermal conductivity. Therefore, the content of graphite or using other conductive materials used should be carefully considered in further studies. Full article
(This article belongs to the Special Issue Functional Cement-Based Composites for Civil Engineering)
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