Materials

Research

19 pages, 7627 KiB

Open AccessArticle

The Effects of Phosphate Compounds on the Microstructure and Mechanical Properties of Fly Ash Geopolymer Mortars

by Piotr Prochon, Tomasz Piotrowski and Maja Kępniak

Materials 2024, 17(22), 5451; https://doi.org/10.3390/ma17225451 - 8 Nov 2024

Viewed by 398

Coal-fired power plants are a main source of energy in Poland. In the rapidly growing demand for the reduction of CO₂ emission in the energy industry, the use of biomass for energy purposes has increased significantly. The combustion of biomass results in [...] Read more.

Coal-fired power plants are a main source of energy in Poland. In the rapidly growing demand for the reduction of CO₂ emission in the energy industry, the use of biomass for energy purposes has increased significantly. The combustion of biomass results in the generation of fly ash, with higher levels of CaO, K₂O, P₂O₅, in contrast to the fly ash derived from the combustion of coal. The aim of this study was to examine the influence of phosphate compounds on fly ash-based geopolymer mortars. Geopolymers were made by mixing two types of fly ash—one from the combustion of wood biomass and the second from the combustion of coal in a heat and power station. Basic activators (NaOH and Na₂SiO₃) were used for the alkali activation. The maximum level of tetraphosphorus decaoxide addition was established at 5% of the total mass of the aluminosilicate precursors mass. The results showed that the phosphate oxide concentration within the specimens demonstrated a positive correlation with flexural and compressive strength across all temporal intervals (7, 28, and 56 days). The porosity, however, for samples with a 5% addition of P₄O₁₀, increased more than twofold in comparison to reference samples (from 4.26% to 9.98%). Full article

(This article belongs to the Special Issue Environmentally Friendly Composites Incorporating Waste Materials)

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14 pages, 6006 KiB

Open AccessArticle

Enhancing Fire Resistance of Geopolymers Modified with Thermal Insulation Additives

by Maja Kępniak, Jakub Zabawski and Piotr Prochoń

Materials 2024, 17(19), 4854; https://doi.org/10.3390/ma17194854 - 2 Oct 2024

Viewed by 695

Abstract

This study aims to improve the fire resistance of geopolymers by adding thermal insulation materials. These additives help the material perform better at high temperatures. Previous research focused on using fly ash, metakaolin, and zeolite in geopolymer composites. This study looks at how [...] Read more.

This study aims to improve the fire resistance of geopolymers by adding thermal insulation materials. These additives help the material perform better at high temperatures. Previous research focused on using fly ash, metakaolin, and zeolite in geopolymer composites. This study looks at how porous additives affect compressive strength and whether non-destructive testing can measure damage after heat exposure. Four temperature tests were set: 400 °C for 60 min, 400 °C for 120 min, 800 °C for 60 min, and a maximum of 658 °C for 120 min. The results showed that the compressive strength and ultrasonic pulse velocity (UPV) dropped as the temperature increased, with a sharp decrease at 800 °C. Unmodified samples broke apart at high temperatures, while modified samples lost 40% to 70% of their strength. The study confirmed that a dense, amorphous matrix improves heat resistance, even with porous additives like fly ash. A link between UPV and compressive strength was found, suggesting non-destructive testing could be useful for checking structural integrity after a fire. Full article

(This article belongs to the Special Issue Environmentally Friendly Composites Incorporating Waste Materials)

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24 pages, 5476 KiB

Open AccessArticle

Energy-Efficient Geopolymer Composites Containing Phase-Change Materials—Comparison of Different Contents and Types

by Agnieszka Przybek, Michał Łach, Rafał Bogucki, Justyna Ciemnicka, Karol Prałat, Artur Koper, Kinga Korniejenko and Adam Masłoń

Materials 2024, 17(19), 4712; https://doi.org/10.3390/ma17194712 - 25 Sep 2024

Viewed by 749

Abstract

The purpose of this study was to analyze the effects of phase-change components on the properties of geopolymer foams. Geopolymer foams are lightweight foamed geopolymers that are characterized by a high degree of porosity. Phase change materials, on the other hand, are compounds [...] Read more.

The purpose of this study was to analyze the effects of phase-change components on the properties of geopolymer foams. Geopolymer foams are lightweight foamed geopolymers that are characterized by a high degree of porosity. Phase change materials, on the other hand, are compounds that, when added to a material, allow it to absorb, store, and then release large amounts of energy. Three types of PCMs, i.e., MikroCaps, GR42, and PX25, were introduced at 15% by weight. Geopolymer materials were produced based on silica fly ash, and hydrogen peroxide H₂O₂ was used to foam the geopolymer structure. The PCM geopolymer composites were cured at 60 °C. The produced materials were tested for physical, chemical, and thermal properties. The tests included oxide and mineral composition analysis of the base material, PCM particle size analysis, apparent density and porosity tests on the foams, water leachability tests, thermal tests (λ, Cv, Cp, α), and structural and textural analysis. The most relevant tests to confirm the performance of the phase-change materials were thermal tests. With the introduction of PCMs, volumetric heat capacity increased by as much as 41% and specific heat by 45%, and thermal diffusivity decreased by 23%. The results confirm the great potential of geopolymer composites as modern insulation materials for buildings and structures. Full article

(This article belongs to the Special Issue Environmentally Friendly Composites Incorporating Waste Materials)

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21 pages, 9045 KiB

Open AccessCommunication

Geothermal Nano-SiO₂ Waste as a Supplementary Cementitious Material for Concrete Exposed at High Critical Temperatures

by Jesús Fernando López-Perales, María Cruz Alonso-Alonso, Francisco Javier Vázquez-Rodríguez, Ana María Guzmán-Hernández, Lauren Yolanda Gómez-Zamorano, Edén Amaral Rodríguez-Castellanos and Rodrigo Puente-Ornelas

Materials 2024, 17(17), 4381; https://doi.org/10.3390/ma17174381 - 5 Sep 2024

Viewed by 765

Abstract

The partial replacement effect of Portland cement by geothermal nano-SiO₂ waste (GNSW) for sustainable Portland-cement-based concrete was investigated to improve the properties of concrete exposed at high critical temperatures. Portland cement was partially replaced by 20 and 30 wt.% of GNSW. The [...] Read more.

The partial replacement effect of Portland cement by geothermal nano-SiO₂ waste (GNSW) for sustainable Portland-cement-based concrete was investigated to improve the properties of concrete exposed at high critical temperatures. Portland cement was partially replaced by 20 and 30 wt.% of GNSW. The partial replacement effect on Portland-cement-based concrete subjected to 350, 550, and 750 °C was evaluated by measuring the weight changes, ultrasonic pulse velocity, thermogravimetric and differential thermal analysis, X-ray diffraction, surface inspection, and scanning electron microscopy under residual conditions. The ultrasonic pulse velocity results showed that the GNSW specimens maintained suitable stability after being heated to 350 °C. The SEM analysis revealed a denser microstructure for the 20 wt.% of partial replacement of Portland cement by GNSW specimen compared to the reference concrete when exposed to temperatures up to 400 °C, maintaining stability in its microstructure. The weight losses were higher for the specimens with partial replacements of GNSW than the reference concrete at 550 °C, which can be attributed to the pozzolanic activity presented by the GNSW, which increases the amounts of CSH gel, leading to a much denser cementitious matrix, causing a higher weight loss compared to the reference concrete. GNSW is a viable supplementary cementitious material, enhancing thermal properties up to 400 °C due to its high pozzolanic activity and filler effect while offering environmental benefits by reducing industrial waste. Full article

(This article belongs to the Special Issue Environmentally Friendly Composites Incorporating Waste Materials)

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16 pages, 5222 KiB

Open AccessArticle

Research on Improving Moisture Resistance of Asphalt Mixture with Compounded Recycled Metallurgical Slag Powders

by Bo Gao, Haiqin Xu, Shaopeng Wu, Huan Wang, Xinkui Yang and Pengrui Chen

Materials 2024, 17(14), 3499; https://doi.org/10.3390/ma17143499 - 15 Jul 2024

Viewed by 619

Abstract

The utilization of steel slag as an alternative material in asphalt mixtures is considered the solution to the problem of the shortage of natural aggregates. However, asphalt mixtures with steel slag show susceptibility to damage caused by moisture, especially in powder form. Therefore, [...] Read more.

The utilization of steel slag as an alternative material in asphalt mixtures is considered the solution to the problem of the shortage of natural aggregates. However, asphalt mixtures with steel slag show susceptibility to damage caused by moisture, especially in powder form. Therefore, blast furnace slag powders were used to compound with steel slag powders as fillers to improve the moisture resistance of asphalt mixtures. The characteristics of the steel slag powders and blast furnace slag powders were investigated initially. Subsequently, the adhesion properties of the asphalt mastics with the powders to the aggregates were evaluated. Finally, the moisture resistances of the asphalt mixtures were identified. The results indicate that the steel slag powder exhibited a notable prevalence of surface pores, which had a more uniform size distribution. In contrast, the blast furnace slag powder exhibited a greater average pore size. The larger specific surface area of the steel slag powder was over 30% larger than that of the blast furnace slag powder, and the superior gelling activity of the blast furnace powder enhanced the adhesion property. Both the steel slag powder and blast furnace slag powder were found to enhance the adhesion properties of the asphalt mastics, while the effect of the steel slag powder was more pronounced, the maximum force difference of which exceeded 200 N. The antagonistic effect of the steel slag powder and blast furnace slag powder on the resistance of the adhesive interface to moisture damage was confirmed by the contact angle test. The incorporation of the blast furnace slag powder markedly enhanced the moisture resistances of the asphalt mixtures. The phenomenon of dynamic moisture damage to the asphalt mixtures was more pronounced under the multicycle times, obviously severer than that in a stable water environment. As the dynamic moisture cycles increased, the degree of destruction gradually approached a steady state. Full article

(This article belongs to the Special Issue Environmentally Friendly Composites Incorporating Waste Materials)

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18 pages, 9821 KiB

Open AccessArticle

Eco-Friendly 3D-Printed Concrete Made with Waste and Organic Artificial Aggregates

by Karolina Butkutė, Vitoldas Vaitkevičius and Fausta Adomaitytė

Materials 2024, 17(13), 3290; https://doi.org/10.3390/ma17133290 - 3 Jul 2024

Viewed by 1596

Abstract

In this research, the results of an experimental study on the use of three alternative components for creating artificial aggregates (AAs) (granules) and their usage in 3D-printed concrete (3DPC) are examined. This study combines AAs made from organic components like hemp shives (HSs), [...] Read more.

In this research, the results of an experimental study on the use of three alternative components for creating artificial aggregates (AAs) (granules) and their usage in 3D-printed concrete (3DPC) are examined. This study combines AAs made from organic components like hemp shives (HSs), pyrolyzed coal (charcoal), waste/municipal solid waste incinerator bottom slag (BS), and a mix of a reference 3DPC with the aforementioned AAs. Particularly, to enhance these properties to make low-carbon 3DPC, in this research, the potential of using AAs as lightweight aggregates was increased to 14% in terms of the mass of the concrete. Each mix was tested in terms of its printability via a preliminary test in a 3D printing laboratory. For an additional comparison with the aforementioned cases, 3DPC was mixed with unprocessed hemp shives, charcoal, and BS. Furthermore, their strength was measured at 28 days, and lastly, their durability parameters and shrinkage were experimentally investigated. Cross-sections of the fragments were studied under a scanning electron microscope. In this study, we achieved improvements in the mechanical properties of AAs for their development and implementation as an innovative way to reduce carbon in 3DPC. Full article

(This article belongs to the Special Issue Environmentally Friendly Composites Incorporating Waste Materials)

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25 pages, 3675 KiB

Open AccessArticle

Influence of the Properties of Different Types of Recycled Aggregate on the Service Properties and Leaching of Paving Blocks Manufactured at Industrial Scale

by Miriam Hernández, Isidro Sánchez, Rosa Navarro, Marina Sánchez and Carlos Rodríguez

Materials 2024, 17(12), 2898; https://doi.org/10.3390/ma17122898 - 13 Jun 2024

Viewed by 702

Abstract

The literature shows that a circular economy can benefit some sectors such as the construction industry. This sector demands huge amounts of raw materials and produces waste when buildings and structures are demolished. This paper explores the possibility of manufacturing at industrial scale [...] Read more.

The literature shows that a circular economy can benefit some sectors such as the construction industry. This sector demands huge amounts of raw materials and produces waste when buildings and structures are demolished. This paper explores the possibility of manufacturing at industrial scale paving blocks using different types of construction and demolition wastes as aggregates, without modifying the commonly used industrial conditions. A total of four different recycled aggregates were used in this research. Both natural and recycled aggregates have been characterized. The dosages were optimized (three different formulations). Prefabricated tests have been carried out on the products manufactured in industrial plants and the evolution of mechanical properties over time has been analysed. The results obtained were analysed statistically by applying the principal component analysis (PCA) method. To ensure the security of the elements manufactured, the ionic leaching of the materials used as recycled aggregate and of the elements produced has been tested. The main implications of this research on the construction industry show that the majority of recycled aggregates used could replace 25% of the natural aggregate in manufactured precast concrete, that the properties of the aggregates should be taken into account in the different standards and that all paving blocks manufactured in this study can be considered environmentally safe (no risk of leaching) according to the Netherland Soil Quality Decree. Therefore, it is evident that it is possible to manufacture on an industrial scale paving blocks with mixed recycled aggregates, concrete and ceramic in nature, both with the fine and coarse fractions that meet the requirements of its reference standard UNE-EN 1338 and the Netherland Soil Quality Decree that evaluates environmental risks due to leaching. Full article

(This article belongs to the Special Issue Environmentally Friendly Composites Incorporating Waste Materials)

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19 pages, 8023 KiB

Open AccessArticle

Microstructural Assessment of Pozzolanic Activity of Ilmenite Mud Waste Compared to Fly Ash in Cement Composites

by Filip Chyliński

Materials 2024, 17(11), 2483; https://doi.org/10.3390/ma17112483 - 21 May 2024

Viewed by 761

Abstract

This paper presents the influence of adding rinsed ilmenite mud waste (R-MUD) on the microstructure of Portland cement composites, compared to similar composites containing fly ash (FA). The aim of the study is the assessment of the pozzolanic activity of ilmenite mud waste [...] Read more.

This paper presents the influence of adding rinsed ilmenite mud waste (R-MUD) on the microstructure of Portland cement composites, compared to similar composites containing fly ash (FA). The aim of the study is the assessment of the pozzolanic activity of ilmenite mud waste by its impact on the microstructure of the cement matrix in comparison to the undoubted pozzolanic activity of fly ash. The presented test results include pore size distribution, phase composition, pozzolanic activity using thermal analysis, R³ bound water test, and microstructural analysis using scanning electron microscopy (SEM). Tests were performed on mortars cured for up to 360 days. The results presented in this paper have shown that R-MUD has a pozzolanic activity level similar to FA or better, which influences pore size distribution in the composite and its microstructure. During the curing process, the microstructure of composites containing R-MUD became more compact and sealed than those with FA, which might also increase their durability. The results of the R³ tests have proven the pozzolanic activity of R-MUD but its level was lower than FA. R-MUD might be a useful substitute for fly ash, especially given the lack of good-quality fly ash on the market. Full article

(This article belongs to the Special Issue Environmentally Friendly Composites Incorporating Waste Materials)

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21 pages, 3097 KiB

Open AccessArticle

Recycling Waste Agricultural Nets as Cement Composites

by Bartosz Zegardło, Chrysanthos Maraveas, Kamil Świeczka and Antoni Bombik

Materials 2024, 17(8), 1828; https://doi.org/10.3390/ma17081828 - 16 Apr 2024

Cited by 1 | Viewed by 996

Abstract

The advancement of agricultural mesh technology has contributed to its improved properties. As a result, agricultural nets are widely adopted in large-scale farming applications, for example, in cereal crop farming. However, a consequence of this increased use of agricultural nets is the accumulation [...] Read more.

The advancement of agricultural mesh technology has contributed to its improved properties. As a result, agricultural nets are widely adopted in large-scale farming applications, for example, in cereal crop farming. However, a consequence of this increased use of agricultural nets is the accumulation of large amounts of waste. The current paper focuses on the recycling of agricultural nets used in wrapping straw bales to develop additives and fillers in cement composites. The research details an analysis of the use of waste agricultural meshes as an ingredient in cement composites. Six test series of different mixtures were conducted. In the first four series, agricultural waste was utilised as an additive in a composite comprising aggregate and cement slurry (the amounts of wasted nets were 20, 40, 60, and 80 kg/m³). In the last test series, the recyclate utilised comprised a mixture of cement slurry and waste only. The composites were subjected to standard tests and thermal resistance tests. The results showcased that that the addition of a net worsened the workability of the concrete mixture, and with increasing amounts of addition, the consistency of the mixture could change from liquid to dense plastic. The flexural strength of the composite decreased with increasing amounts of recyclate. In subsequent test series, the flexural strength value was lower than that of the control (3.93 MPa), from 7.38% (3.64 MPa) for the composite with 20 kg/m³ of recyclate to 37.66% (2.45 MPa) for the composite with of 80 kg/m³ recyclate. The flexural strength value of the net-filled composite without aggregate was very high (10.44 MPa), where the value obtained for the control composite was 62.36% lower. The results of the compressive strength test showed a decrease in this parameter with increasing amounts of additive. The value assessed for the control composite was 27.99 MPa. As expected, the composite that had no aggregate and consisted of only recycled filler had the lowest compressive strength. The value of this parameter was 13.07 MPa, and it was 53.31% lower than that of the control composite. The results of the tests of resistance to temperatures were similar to those recorded for the composites with polypropylene fibres. All composites demonstrated a significant decrease in their compressive and flexural strength after annealing. SEM imaging showed that the net fibres were closely bonded to the cement stone. Finally, it was concluded that recyclates performed best as fillers in lightweight composites with a low density, low absorption, high flexural strength, and satisfactory compressive strength. Full article

(This article belongs to the Special Issue Environmentally Friendly Composites Incorporating Waste Materials)

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17 pages, 6289 KiB

Open AccessArticle

Properties of Geopolymer Mixtures Incorporating Recycled Ceramic Fines

by Katarzyna Kalinowska-Wichrowska, Edyta Pawluczuk, Filip Chyliński, Hwa Kian Chai, Magdalena Joka Yildiz, Aleksandra Chuczun and Stanisław Łuniewski

Materials 2024, 17(8), 1740; https://doi.org/10.3390/ma17081740 - 10 Apr 2024

Viewed by 1015

Abstract

This research aimed to optimize the production conditions for geopolymer matrices by investigating the combination of heat curing conditions and the incorporation of recycled ceramic fines (CFs) as a partial replacement material for fly ash (FA). The obtained physical and mechanical properties of [...] Read more.

This research aimed to optimize the production conditions for geopolymer matrices by investigating the combination of heat curing conditions and the incorporation of recycled ceramic fines (CFs) as a partial replacement material for fly ash (FA). The obtained physical and mechanical properties of the composites confirmed the positive impact resulting from increasing the curing temperature from 65 °C to 85 °C and using CFs in the amount of 37.5% as a replacement for FA. The results were from laboratory tests performed to evaluate compressive strength, bending strength, bulk density, and water absorption of the geopolymer mixes. In addition, microscopic observations and porosity assessment were also performed, which confirmed that a further increase in the replacement of FA by CFs causes an increase in the porosity of the mixes and, thus, a decrease in all the assessed properties that are relevant to their practical use. Full article

(This article belongs to the Special Issue Environmentally Friendly Composites Incorporating Waste Materials)

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10 pages, 3022 KiB

Open AccessArticle

Assessment of the Thermal Properties of Gypsum Plaster with Plastic Waste Aggregates

by Alejandra Vidales-Barriguete, Eva Barreira and Susana Gomes Dias

Materials 2024, 17(7), 1663; https://doi.org/10.3390/ma17071663 - 4 Apr 2024

Cited by 1 | Viewed by 867

Abstract

Building material manufacturers must support new production models that encourage the manufacture of more efficient and sustainable products. This includes thinking about savings in the use of raw materials, a contribution to the energy efficiency of buildings during their useful life, and a [...] Read more.

Building material manufacturers must support new production models that encourage the manufacture of more efficient and sustainable products. This includes thinking about savings in the use of raw materials, a contribution to the energy efficiency of buildings during their useful life, and a reduction in the generation and deposit of waste in landfills. In this research, an analysis of the thermal properties of gypsum composites added with plastic waste is carried out using the most common methods, the steady state method and the transient plane source method, and the effect of water saturation on these composites is tested. The results show an improvement in the thermal performance of the composites (values reduced with respect to the reference by 4–7%), despite their heterogeneity, as well as a variation in the measurements carried out, depending on the method used for the measurements (variation up to 10%). It is also found that the degree of humidity negatively affects the thermal conductivity coefficient but, on the contrary, this coefficient is not altered in the composites with plastic waste, due to their lower hygroscopicity. Therefore, it is considered that the proposed eco-plasters are a good alternative to traditional plasters, with which to contribute to the achievement of the objectives of the current European directives on waste and circular economy. Full article

(This article belongs to the Special Issue Environmentally Friendly Composites Incorporating Waste Materials)

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17 pages, 14641 KiB

Open AccessArticle

Testing the Influence of Metakaolinite and Zeolite on the Adhesion of BFRP and GFRP Bars to Concrete

by Julita Krassowska, Paweł Wolka, Kostiantyn Protchenko and Alejandra Vidales-Barriguete

Materials 2023, 16(23), 7435; https://doi.org/10.3390/ma16237435 - 29 Nov 2023

Cited by 2 | Viewed by 1040

Abstract

Today’s sustainable development policy in Europe, which is driven by concerns about the greenhouse effect and environmental protection, mandates a reduction in CO₂ emissions into the atmosphere. The cement industry and steel mills that produce reinforcing bars are among the largest and [...] Read more.

Today’s sustainable development policy in Europe, which is driven by concerns about the greenhouse effect and environmental protection, mandates a reduction in CO₂ emissions into the atmosphere. The cement industry and steel mills that produce reinforcing bars are among the largest and most emissions-intensive sectors emitting CO₂ into the atmosphere. This article analyzes the possibility of achieving significant reductions in CO₂ emissions by using basalt bars (BFRP) and glass bars (GFRP) in concrete structures, and—in the case of concrete—by using cement with the addition of metakaolinite and zeolite. There is a lack of literature reports on whether modifying concrete with the additions of metakaolinite and zeolite as substitutes for part of the cement affects the adhesion of FRP bars to concrete. It can be assumed, however, that improving the microstructure of concrete also improves the contact zone between the bar and the concrete. The aim of this research is to fill the aforementioned gap in the literature data by determining how the presence of metakaolinite and zeolite affects the adhesion of reinforcing bars to concrete and testing selected properties of hardened concrete. The test samples were prepared following the appropriate beam test procedure. The obtained results made it possible to perform a comparative analysis of reference samples and those with metakaolinite and zeolite additions. The research showed that introducing active pozzolanic additives in the form of metakaolinite and zeolite into concrete improved adhesion stress values by approximately 20% for glass GFRP bars and 15% for basalt BFRP bars, especially in the destruction phase. Full article

(This article belongs to the Special Issue Environmentally Friendly Composites Incorporating Waste Materials)

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18 pages, 4059 KiB

Open AccessArticle

Effects of Chemicals Exposure on the Durability of Geopolymer Concrete Incorporated with Silica Fumes and Nano-Sized Silica at Varying Curing Temperatures

by Sagar Paruthi, Ibadur Rahman, Asif Husain, Mohd Abul Hasan and Afzal Husain Khan

Materials 2023, 16(18), 6332; https://doi.org/10.3390/ma16186332 - 21 Sep 2023

Cited by 10 | Viewed by 1211

Abstract

Durable concrete significantly reduces the spalling caused by chemical damage. The objective of current research is to substitute cement with supplementary such as fly ash (FA), ground granulated blast furnace slag (GGBS), and alccofine (AF). Additionally, the impact of nano-silica (NS) and silica [...] Read more.

Durable concrete significantly reduces the spalling caused by chemical damage. The objective of current research is to substitute cement with supplementary such as fly ash (FA), ground granulated blast furnace slag (GGBS), and alccofine (AF). Additionally, the impact of nano-silica (NS) and silica fumes (SF) on the GPC durability when cured at various temperatures has been attempted. In order to perform this, GPC samples were produced by combining NS and SF at proportions of 0.5% NS + 5% SF, 1% NS + 10% SF, and 1.5% NS + 15% SF, and then cured at temperatures of 27 °C, 60 °C, 90 °C, and 120 °C, respectively. In this research, all concrete specimens were continuously immersed for twelve weeks under four different chemicals, i.e., HCl (2%), H₂SO₄ (2%), NaCl (6%), and Na₂SO₄ (6%). The influence of chemical attack on the qualities of concrete was examined by evaluating the water absorption, sorptivity, loss of mass, and loss of GPC strength. The durability aspect is also studied by visual appearance and mass loss under harmful chemical attack. The combination of GPC with integrated NS and SF affords great resistance against chemical attacks. The percentages of these two components are 1.5% and 15%. For GPC specimens, when cured at 90 °C, the resultant strength is found at its maximum. Full article

(This article belongs to the Special Issue Environmentally Friendly Composites Incorporating Waste Materials)

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