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3 pages, 181 KiB

Open AccessEditorial

Recycled Materials for Concrete and Other Composites

by Malgorzata Ulewicz

Materials 2021, 14(9), 2279; https://doi.org/10.3390/ma14092279 - 28 Apr 2021

Cited by 1 | Viewed by 1850

Abstract

In recent years, industry, including the construction sector, has been focused on effectively reducing the consumption of natural resources, in compliance with the idea of sustainable development [...] Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

Research

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19 pages, 3129 KiB

Open AccessArticle

Biomineralization of Plastic Waste to Improve the Strength of Plastic-Reinforced Cement Mortar

by Seth Kane, Abby Thane, Michael Espinal, Kendra Lunday, Hakan Armağan, Adrienne Phillips, Chelsea Heveran and Cecily Ryan

Materials 2021, 14(8), 1949; https://doi.org/10.3390/ma14081949 - 13 Apr 2021

Cited by 11 | Viewed by 4579

Abstract

The development of methods to reuse large volumes of plastic waste is essential to curb the environmental impact of plastic pollution. Plastic-reinforced cementitious materials (PRCs), such as plastic-reinforced mortar (PRM), may be potential avenues to productively use large quantities of low-value plastic waste. [...] Read more.

The development of methods to reuse large volumes of plastic waste is essential to curb the environmental impact of plastic pollution. Plastic-reinforced cementitious materials (PRCs), such as plastic-reinforced mortar (PRM), may be potential avenues to productively use large quantities of low-value plastic waste. However, poor bonding between the plastic and cement matrix reduces the strength of PRCs, limiting its viable applications. In this study, calcium carbonate biomineralization techniques were applied to coat plastic waste and improved the compressive strength of PRM. Two biomineralization treatments were examined: enzymatically induced calcium carbonate precipitation (EICP) and microbially induced calcium carbonate precipitation (MICP). MICP treatment of polyethylene terephthalate (PET) resulted in PRMs with compressive strengths similar to that of plastic-free mortar and higher than the compressive strengths of PRMs with untreated or EICP-treated PET. Based on the results of this study, MICP was used to treat hard-to-recycle types 3–7 plastic waste. No plastics investigated in this study inhibited the MICP process. PRM samples with 5% MICP-treated polyvinyl chloride (PVC) and mixed type 3–7 plastic had compressive strengths similar to plastic-free mortar. These results indicate that MICP treatment can improve PRM strength and that MICP-treated PRM shows promise as a method to reuse plastic waste. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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12 pages, 4394 KiB

Open AccessArticle

Interface Bonding Behavior of Concrete-Filled Steel Tube Blended with Circulating Fluidized Bed Bottom Ash

by Lan Liu, Lei He, Zhi Cheng, Xiaoyi Wang, Zhe Ma and Xinrong Cheng

Materials 2021, 14(6), 1529; https://doi.org/10.3390/ma14061529 - 20 Mar 2021

Cited by 10 | Viewed by 2070

Abstract

The interface bonding behavior between the steel tube and the concrete of concrete-filled steel tube (CFST) blended with circulating fluidized bed bottom ash (CFB-BA) was investigated in this study. A total of 8 groups of CFSTs stub columns were prepared with different dosage [...] Read more.

The interface bonding behavior between the steel tube and the concrete of concrete-filled steel tube (CFST) blended with circulating fluidized bed bottom ash (CFB-BA) was investigated in this study. A total of 8 groups of CFSTs stub columns were prepared with different dosage of CFB-BA, water-binder ratio (W/B), and interface bonding length. A series of push-out tests were carried out to acquire the data representing the interface bonding behavior. The results show that the dosage of CFB-BA has a direct effect on interface bonding behavior of CFST. CFB-BA can improve the interface bonding behavior of CFST. The highest ultimate bonding load and strength are achieved when the dosage of CFB-BA is 30%. When the dosage of CFB-BA increases to 50%, its interface bonding behavior decreases, but is still better than that of CFST without CFB-BA. W/B has a negative correlation with the interface bonding behavior of CFST. While the W/B increases, the interface bonding load and strength of CFST decreases. The increase of the interface bonding length can improve the interface bonding load, but cannot improve the interface bonding strength. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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18 pages, 17581 KiB

Open AccessArticle

Drying Shrinkage and Rapid Chloride Penetration Resistance of Recycled Aggregate Concretes Using Cement Paste Dissociation Agent

by Sungchul Yang and Hyewon Lee

Materials 2021, 14(6), 1478; https://doi.org/10.3390/ma14061478 - 17 Mar 2021

Cited by 13 | Viewed by 2634

Abstract

In the present study, a recycled concrete aggregate (RCA) coating treatment using a cement paste dissociation agent (CPDA) with different mixing methods was newly incorporated in RCA concrete mixtures. First, a preliminary test program was conducted to determine the proper dosage of the [...] Read more.

In the present study, a recycled concrete aggregate (RCA) coating treatment using a cement paste dissociation agent (CPDA) with different mixing methods was newly incorporated in RCA concrete mixtures. First, a preliminary test program was conducted to determine the proper dosage of the CPDA solution throughout its RCA concrete test results from compressive strength, flexural strength, and elastic modulus. Then, a series of experimental tests were carried out to investigate the effect of RCA coating treatment, different mixing method such as the equivalent mortar volume (EMV) method and conventional method, and different RCA replacement ratios on durability test results of RCA concrete such as drying shrinkage values and rapid chloride penetration test (RCPT) values. The test results showed that all RCA concretes mixed with the coated RCAs were found to be workable regardless of different mix methods, with the slump and air contents of all the mixes being almost identical. All the concrete specimens, which were mixed with the coated RCAs with CPDA solution, represented lower drying shrinkage and RCPT values than those mixed without RCA coating treatment, regardless of different mix proportioning methods or RCA replacement ratios. This holds for the concrete specimens proportioned with the EMV method, regardless of different RCA replacement ratios. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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12 pages, 2772 KiB

Open AccessArticle

Properties and Structure of Concretes Doped with Production Waste of Thermoplastic Elastomers from the Production of Car Floor Mats

by Malgorzata Ulewicz and Alina Pietrzak

Materials 2021, 14(4), 872; https://doi.org/10.3390/ma14040872 - 11 Feb 2021

Cited by 17 | Viewed by 2279

Abstract

This article presents physical and mechanical properties of concrete composites that include waste thermoplastic elastomer (TPE) from the production process of car floor mats. Waste elastomer (2–8 mm fraction) was used as a substitute for fine aggregate in quantities of 2.5, 5.0, 7.5, [...] Read more.

This article presents physical and mechanical properties of concrete composites that include waste thermoplastic elastomer (TPE) from the production process of car floor mats. Waste elastomer (2–8 mm fraction) was used as a substitute for fine aggregate in quantities of 2.5, 5.0, 7.5, and 10% of the cement weight. For all series of concrete, the following tests were carried out: compression strength, bending tensile strength, splitting tensile strength, absorbability, density, resistance to water penetration under pressure, frost resistance, and abrasion resistance, according to applicable standards. Moreover, SEM/EDS analysis was carried out on the surface microstructure of synthesized concrete composites. It was proven that the use of production waste from the production process of car floor mats in the quantity of 2.5% does not influence the change of the concrete microstructure and it does not result in the decrease of the mechanical parameters of concrete modified with waste. All concrete modified with the addition of waste meet standards requirements after carrying out 15 cycles of freezing and thawing, and the average decrease in compression strength did not exceed 20%. Adding waste in the quantity of 2.5% allows for limiting the use of aggregate by about 5%, which is beneficial for the natural environment. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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18 pages, 3539 KiB

Open AccessArticle

The Chemical-Mineralogical Characterization of Recycled Concrete Aggregates from Different Sources and Their Potential Reactions in Asphalt Mixtures

by Edgar H. Sánchez-Cotte, Carlos Albeiro Pacheco-Bustos, Ana Fonseca, Yaneth Pineda Triana, Ronald Mercado, Julián Yepes-Martínez and Ricardo Gabriel Lagares Espinoza

Materials 2020, 13(24), 5592; https://doi.org/10.3390/ma13245592 - 8 Dec 2020

Cited by 21 | Viewed by 4368

Abstract

The incorporation of a recycled concrete aggregate (RCA) as a replacement of natural aggregates (NA) in road construction has been the subject of recent research. This tendency promotes sustainability, but its use depends mainly on the final product’s properties, such as chemical stability. [...] Read more.

The incorporation of a recycled concrete aggregate (RCA) as a replacement of natural aggregates (NA) in road construction has been the subject of recent research. This tendency promotes sustainability, but its use depends mainly on the final product’s properties, such as chemical stability. This study evaluates the physical and chemical properties of RCAs from two different sources in comparison with the performance of NA. One RCA was obtained from the demolition of a building (recycled concrete aggregate of a building—RCAB) and another RCA from the rehabilitation of a Portland cement concrete pavement (recycled concrete aggregate from a pavement—RCAP). Characterization techniques such as X-ray fluorescence (XRF), X-ray diffraction (XRD), UV spectroscopy, and atomic absorption spectrometry were used to evaluate the RCAs’ coarse fractions for chemical potential effects on asphalt mixtures. NA was replaced with RCA at 15%, 30%, and 45% for each size of the coarse fractions (retained 19.0, 12.5, 9.5, and 4.75 sieves in mm). The mineralogical characterization results indicated the presence of quartz (SiO₂) and calcite (CaCO₃) as the most significant constituents of the aggregates. XFR showed that RCAs have lower levels of CaO and Al₂O₃ concerning NA. Potential reactions in asphalt mixtures by nitration, sulfonation, amination of organic compounds, and reactions by alkaline activation in the aggregates were discarded due to the minimum concentration of components such as NO₂, (–SO₃H), (–SO₂Cl), and (Na) in the aggregates. Finally, this research concludes that studied RCAs might be used as replacements of coarse aggregate in asphalt mixtures since chemical properties do not affect the overall chemical stability of the asphalt mixture. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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15 pages, 3544 KiB

Open AccessEditor’s ChoiceArticle

Use of GRP Pipe Waste Powder as a Filler Replacement in Hot-Mix Asphalt

by Ahmet Beycioğlu, Orhan Kaya, Zeynel Baran Yıldırım, Baki Bağrıaçık, Magdalena Dobiszewska, Nihat Morova and Suna Çetin

Materials 2020, 13(20), 4630; https://doi.org/10.3390/ma13204630 - 16 Oct 2020

Cited by 6 | Viewed by 3487

Abstract

There is an increasing global trend to find sustainable, environmentally friendly and cost-effective materials as an alternative to limited natural raw materials. Similarly, the use of waste materials has been gaining popularity in the production of hot-mix asphalt (HMA). In this study, the [...] Read more.

There is an increasing global trend to find sustainable, environmentally friendly and cost-effective materials as an alternative to limited natural raw materials. Similarly, the use of waste materials has been gaining popularity in the production of hot-mix asphalt (HMA). In this study, the sustainable use of glass-fiber-reinforced polyester (GRP) pipe waste powder (GRP-WP), gathered from the cutting and milling process of GRP pipe production, utilizing it in asphalt mixes as a filler, is evaluated based on lab testing to find out: (i) if it produces similar or better performance compared to the most conventionally available filler material (limestone) and, (ii) if so, what would be the optimum GRP-WP filler content to be used in asphalt mixes. For this reason, an experimental test matrix consisting of 45 samples with three different amounts of binder content (4%, 4.5% and 5.0%), and a 5% filler content with five different percentages of the GRP-WP content (0%, 25%, 50%, 75% and 100% replacement by weight of the filler), was prepared to figure out which sample would produce the similar Marshall stability and flow values compared to the control samples while also satisfying specification limits. It was found that the samples with 4.5% binder content, 3.75% GRP-WP and 1.25% limestone filler content produced the results both satisfying the specification requirements and providing an optimum mix design. It is believed that use of GRP-WP waste in HMA production would be a very useful way of recycling GRP-WP. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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20 pages, 2801 KiB

Open AccessArticle

Corrosion Behavior of Steel-Reinforced Green Concrete Containing Recycled Coarse Aggregate Additions in Sulfate Media

by Abigail Landa-Sánchez, Juan Bosch, Miguel Angel Baltazar-Zamora, René Croche, Laura Landa-Ruiz, Griselda Santiago-Hurtado, Victor M. Moreno-Landeros, Javier Olguín-Coca, Luis López-Léon, José M. Bastidas, José M. Mendoza-Rangel, Jacob Ress and David. M. Bastidas

Materials 2020, 13(19), 4345; https://doi.org/10.3390/ma13194345 - 29 Sep 2020

Cited by 18 | Viewed by 3388

Abstract

Novel green concrete (GC) admixtures containing 50% and 100% recycled coarse aggregate (RCA) were manufactured according to the ACI 211.1 standard. The GC samples were reinforced with AISI 1080 carbon steel and AISI 304 stainless steel. Concrete samples were exposed to 3.5 wt.% [...] Read more.

Novel green concrete (GC) admixtures containing 50% and 100% recycled coarse aggregate (RCA) were manufactured according to the ACI 211.1 standard. The GC samples were reinforced with AISI 1080 carbon steel and AISI 304 stainless steel. Concrete samples were exposed to 3.5 wt.% Na₂SO₄ and control (DI-water) solutions. Electrochemical testing was assessed by corrosion potential (E_corr) according to the ASTM C-876-15 standard and a linear polarization resistance (LPR) technique following ASTM G59-14. The compressive strength of the fully substituted GC decreased 51.5% compared to the control sample. Improved corrosion behavior was found for the specimens reinforced with AISI 304 SS; the corrosion current density (i_corr)values of the fully substituted GC were found to be 0.01894 µA/cm² after Day 364, a value associated with negligible corrosion. The 50% RCA specimen shows good corrosion behavior as well as a reduction in environmental impact. Although having lower mechanical properties, a less dense concrete matrix and high permeability, RCA green concrete presents an improved corrosion behavior thus being a promising approach to the higher pollutant conventional aggregates. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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14 pages, 3973 KiB

Open AccessArticle

Recycled Nylon Fiber from Waste Fishing Nets as Reinforcement in Polymer Cement Mortar for the Repair of Corroded RC Beams

by Teeranai Srimahachota, Hiroshi Yokota and Yoshikazu Akira

Materials 2020, 13(19), 4276; https://doi.org/10.3390/ma13194276 - 25 Sep 2020

Cited by 32 | Viewed by 4065

Abstract

Waste fishing nets were utilized as recycled nylon (RN) short fiber to improve the mechanical properties of cement mortar. RN and manufactured polyethylene (PE) fibers were added to polymer cement mortar (PCM) as a reinforcement, and fiber-reinforced PCM was sprayed on the section [...] Read more.

Waste fishing nets were utilized as recycled nylon (RN) short fiber to improve the mechanical properties of cement mortar. RN and manufactured polyethylene (PE) fibers were added to polymer cement mortar (PCM) as a reinforcement, and fiber-reinforced PCM was sprayed on the section of reinforced concrete (RC) beams. Normal RC beams and the upgraded RC beams were placed in the tidal zone for 14 months to induce rebar corrosion. Consequently, a repair operation took place by the removal of the concrete cover then spraying fiber-reinforced PCM. The tested RC beams were subjected to four-point flexural tests to study their load-carrying capacity. It was found that the fibers helped transfer stresses through cracks and distribute stresses by transforming a single wide crack into many small cracks. Overall, the experimental results showed that recycled nylon fibers from waste fishing nets have great potential to be used as a strengthening fiber in cementitious material. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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24 pages, 7161 KiB

Open AccessArticle

Research on the Mechanical Properties of Recycled Aggregate Concrete under Uniaxial Compression Based on the Statistical Damage Model

by Weifeng Bai, Wenhao Li, Junfeng Guan, Jianyou Wang and Chenyang Yuan

Materials 2020, 13(17), 3765; https://doi.org/10.3390/ma13173765 - 26 Aug 2020

Cited by 21 | Viewed by 2915

Abstract

In this paper, uniaxial compression tests were carried out for recycled aggregate concrete with water cement ratios of 0.38, 0.49, and 0.66 and replacement ratios of 0%, 25%, 50%, 75%, and 100%, respectively. The influence of the replacement ratio of recycled aggregate and [...] Read more.

In this paper, uniaxial compression tests were carried out for recycled aggregate concrete with water cement ratios of 0.38, 0.49, and 0.66 and replacement ratios of 0%, 25%, 50%, 75%, and 100%, respectively. The influence of the replacement ratio of recycled aggregate and water cement ratio on the strength, elastic modulus, and deformation characteristics of concrete was discussed. The results show that the replacement rate of recycled aggregate has a significant effect on the macro stress–strain behavior of concrete. In the case of a constant water cement ratio, the peak nominal stress first decreases and then increases with the increase of the replacement rate; while the water cement ratios equal 0.38, 0.49, and 0.66, the corresponding transition states are 25%, 50%, and 50% of the replacement rate, respectively. The deformation and failure is characterized by two stages: distributed damage and local failure. Combined with the statistical damage mechanics, the influence of the aggregate replacement rate on the damage evolution mechanism of recycled concrete on a mesoscopic scale was explored. Two mesoscopic damage modes, fracture and yield, are considered. Their cumulative evolutions are assumed to follow triangular probability distributions, which could be characterized by four parameters. The peak nominal stress state and the critical state are distinguished, and the latter is defined as a precursor to local failure. With the increase of the replacement rate of recycled aggregate, the inhomogeneous evolution of mesoscopic damage shows obvious regular change, which is consistent with the internal chemical and physical mechanism and macro nonlinear stress–strain behavior. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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13 pages, 3147 KiB

Open AccessArticle

Properties of a Three-Component Mineral Road Binder for Deep-Cold Recycling Technology

by Zdzisława Owsiak, Przemysław Czapik and Justyna Zapała-Sławeta

Materials 2020, 13(16), 3585; https://doi.org/10.3390/ma13163585 - 13 Aug 2020

Cited by 13 | Viewed by 2296

Abstract

This study examined the physical properties of a three-component mineral binder that is typically used in deep-cold recycling. Test binders were produced using Portland cement, hydrated lime, and cement bypass dust (CBPD) as a byproduct derived from cement production. The suitability of CBPD [...] Read more.

This study examined the physical properties of a three-component mineral binder that is typically used in deep-cold recycling. Test binders were produced using Portland cement, hydrated lime, and cement bypass dust (CBPD) as a byproduct derived from cement production. The suitability of CBPD for use in road binders was assessed. Effects of the three-component binder composition on the setting time, soundness, consistency, and tensile and compressive strengths of the cement pastes and mortars were determined. The pastes and mortars of the same consistency obtained at different w/b ratios were tested. On this basis, the mixture proportions resulting in road binders satisfying the requirements of PN-EN 13282-2:2015 were determined. By mixing cement, lime, and CBPD during the tests, binder classes N1 to N3 were obtained. The replacement of 40% of cement mass with the CBPD high in free lime produced road binders suitable for recycled base layers. The total content of CBPD and hydrated lime in the road binder should not exceed 50% by mass. The potential risk of mortar strength reduction due to KCl recrystallization was discussed. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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18 pages, 8605 KiB

Open AccessArticle

Physical Properties and Microstructure of Concrete with Waste Basalt Powder Addition

by Magdalena Dobiszewska and Ahmet Beycioğlu

Materials 2020, 13(16), 3503; https://doi.org/10.3390/ma13163503 - 8 Aug 2020

Cited by 32 | Viewed by 3829

Abstract

The natural aggregates are one of the main components in the production of concrete. Although deposits of natural aggregates lie on the earth’s surface or at low depths and belong to common deposits, the shortage of aggregate, especially natural sand, is presently observed [...] Read more.

The natural aggregates are one of the main components in the production of concrete. Although deposits of natural aggregates lie on the earth’s surface or at low depths and belong to common deposits, the shortage of aggregate, especially natural sand, is presently observed in many countries. In such a situation, one is looking for other materials that can be used as a substitute for natural aggregates in mortars and concrete production. This paper presents the results of an experimental investigation carried out to evaluate the potential usage of waste basalt powder in concrete production. For this purpose, the waste basalt powder, which is a by-product of the production of mineral–asphalt mixtures, was substituted with 10%, 20%, and 30% sand replacement. In the experimental program, the workability, compressive strength, water transport properties, and microstructural performances were evaluated. The results showed that the production of concretes that feature a strong internal structure with decreased water transport behavior is possible with waste basalt usage. Furthermore, when waste basalt powder is used as a partial sand replacement, the compressive strength of concretes can be increased up to 25%. According to the microstructural analyses, the presence of basalt powder in concrete mixes is beneficial for cement hydration products, and basalt powder substituted concretes have lower porosity within the interfacial transition zone. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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13 pages, 3252 KiB

Open AccessArticle

Industrial Waste Utilization of Carbon Dust in Sustainable Cementitious Composites Production

by Mohammad R. Irshidat and Nasser Al-Nuaimi

Materials 2020, 13(15), 3295; https://doi.org/10.3390/ma13153295 - 24 Jul 2020

Cited by 15 | Viewed by 2386

Abstract

This paper experimentally investigates the effect of utilization of carbon dust generated as an industrial waste from aluminum factories in cementitious composites production. Carbon dust is collected, characterized, and then used to partially replace cement particles in cement mortar production. The effect of [...] Read more.

This paper experimentally investigates the effect of utilization of carbon dust generated as an industrial waste from aluminum factories in cementitious composites production. Carbon dust is collected, characterized, and then used to partially replace cement particles in cement mortar production. The effect of adding different dosages of carbon dust in the range of 5% to 40% by weight of cement on compressive strength, microstructure, and chemical composition of cement mortar is investigated. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray fluorescence (XRF) analysis are used to justify the results. Experimental results show that incorporation of carbon dust in cement mortar production not only reduces its environmental side effects but also enhances the strength of cementitious composites. Up to 10% carbon dust by weight of cement can be added to the mixture without adversely affecting the strength of the mortar. Any further addition of carbon dust would decrease the strength. Best enhancement in compressive strength (27%) is achieved in the case of using 5% replacement ratio. SEM images show that incorporation of small amount of carbon dust (less than 10%) lead to produce denser and more compact-structure cement mortar. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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20 pages, 6033 KiB

Open AccessArticle

Enhancement of Mechanical Properties and Porosity of Concrete Using Steel Slag Coarse Aggregate

by Md Jihad Miah, Md. Munir Hossain Patoary, Suvash Chandra Paul, Adewumi John Babafemi and Biranchi Panda

Materials 2020, 13(12), 2865; https://doi.org/10.3390/ma13122865 - 26 Jun 2020

Cited by 36 | Viewed by 4588

Abstract

This paper investigates the possibility of utilizing steel slags produced in the steelmaking industry as an alternative to burnt clay brick aggregate (BA) in concrete. Within this context, physical, mechanical (i.e., compressive and splitting tensile strength), length change, and durability (porosity) tests were [...] Read more.

This paper investigates the possibility of utilizing steel slags produced in the steelmaking industry as an alternative to burnt clay brick aggregate (BA) in concrete. Within this context, physical, mechanical (i.e., compressive and splitting tensile strength), length change, and durability (porosity) tests were conducted on concrete made with nine different percentage replacements (0%, 10%, 20%, 30%, 40%, 50%, 60%, 80%, and 100% by volume of BA) of BA by induction of furnace steel slag aggregate (SSA). In addition, the chemical composition of aggregate through X-ray fluorescence (XRF) analysis and microstructural analysis through scanning electron microscopy (SEM) of aggregates and concrete were performed. The experimental results show that the physical and mechanical properties of concrete made with SSA were significantly higher than that of concrete made with BA. The compressive and tensile strength increased by 73% when SSA fully replaced BA. The expansion of concrete made with SSA was a bit higher than the concrete made with BA. Furthermore, a significant lower porosity was observed for concrete made with SSA than BA, which decreased by 40% for 100% SSA concrete than 100% BA concrete. The relation between compressive and tensile strength with the porosity of concrete mixes are in agreement with the relationships presented in the literature. This study demonstrates that SSA can be used as a full replacement of BA, which is economical, conserves the natural aggregate, and is sustainable building material since burning brick produces a lot of CO₂. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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24 pages, 8330 KiB

Open AccessArticle

The Influence of Calcareous Fly Ash on the Effectiveness of Plasticizers and Superplasticizers

by Jacek Gołaszewski, Tomasz Ponikiewski, Aleksandra Kostrzanowska-Siedlarz and Patrycja Miera

Materials 2020, 13(10), 2245; https://doi.org/10.3390/ma13102245 - 13 May 2020

Cited by 7 | Viewed by 2361

Abstract

Due to the rational shaping of the environment and the management of environmental resources in accordance with the principle of sustainable development, calcareous fly ash (CFA)—high-calcium as a by-product of lignite combustion—is a valuable addition to concrete. This additive, however, due to its [...] Read more.

Due to the rational shaping of the environment and the management of environmental resources in accordance with the principle of sustainable development, calcareous fly ash (CFA)—high-calcium as a by-product of lignite combustion—is a valuable addition to concrete. This additive, however, due to its high-water demand lowers the workability of the concrete mix, which is a problem, especially in the first 90 min after mixing the components of the mix. In order to meet this challenge, plasticizers (P) and superplasticizers (SP) for concrete are used with various effects which are designed to reduce the yield value and plastic viscosity. To check the technical efficiency of admixtures P and SP with different chemical bases, the main objective of this research was to investigate the influence of raw and ground CFA on the rheological properties and other side effects of admixtures, such as the amount of air in the mixture and the amount of heat of hydration. The use of P, particularly SP, effectively improves the workability of the mortar containing CFA, especially ground CFA. With these admixtures, it is possible to obtain mortars containing ground CFA with similar rheological properties to mortars without its addition. To obtain a specific workability of mortar with CFA, it is usually necessary to introduce a higher dose of P or SP than used for mortars without CFA. The presence of raw CFA does not alter the effectiveness of P and strongly reduces the effectiveness of SP. The reduced effectiveness of SP manifests primarily as a high workability lost. The presence of ground CFA does not change the effectiveness of P (or is higher). The effectiveness of the superplasticizer SNF (with a chemical base of naphthalene sulfonate) and PE (with a chemical base of polycarboxylate ether) is slightly lower or does not change. The effectiveness of the superplasticizer SMF (with a chemical base of melamine sulfonates) is significantly lower. We found that the presence of ash affects the efficiency of P and SP, while processing via the grinding of ash makes the effect negligible. These results are novel in both their cognitive and practical aspects. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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12 pages, 2943 KiB

Open AccessArticle

Mechanisms Accompanying Chromium Release from Concrete

by Anna Król

Materials 2020, 13(8), 1891; https://doi.org/10.3390/ma13081891 - 17 Apr 2020

Cited by 7 | Viewed by 2677

Abstract

The use of mineral additives from the power and metallurgy industries in the production of building materials still raises questions about the ecological safety of such materials. These questions are particularly associated with the release of heavy metals. The article presents research related [...] Read more.

The use of mineral additives from the power and metallurgy industries in the production of building materials still raises questions about the ecological safety of such materials. These questions are particularly associated with the release of heavy metals. The article presents research related to the leaching of chromium from concretes made of Portland cement CEM I and slag cement CEM III/B (containing 75% of granulated blast furnace slag). Concrete was evaluated for leaching mechanisms that may appear during tank test over the long term (64 days). It has been presented that the dominating process associated with the leaching of chromium from both types of concrete is surface wash-off. Between the 9th and 64th day of the test, leaching of Portland cement concrete can be diffusion controlled. It has been proven that the participation of slag in the composition of concrete does not affect the level of leaching of chromium into the environment from concrete. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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18 pages, 3438 KiB

Open AccessArticle

Post-Pyrolytic Carbon as a Phase Change Materials (PCMs) Carrier for Application in Building Materials

by Michał Ryms, Katarzyna Januszewicz, Paweł Kazimierski, Justyna Łuczak, Ewa Klugmann-Radziemska and Witold M. Lewandowski

Materials 2020, 13(6), 1268; https://doi.org/10.3390/ma13061268 - 11 Mar 2020

Cited by 24 | Viewed by 3169

Abstract

This article covers new application for char as a carrier of phase-change materials (PCM) that could be used as an additive to building materials. Being composed of bio-char and PCM, the granulate successfully competes with more expensive commercial materials of this type, such [...] Read more.

This article covers new application for char as a carrier of phase-change materials (PCM) that could be used as an additive to building materials. Being composed of bio-char and PCM, the granulate successfully competes with more expensive commercial materials of this type, such as Micronal^® PCM. As a PCM carrier, char that was obtained from the pyrolysis of chestnut fruit (Aesculus hippocastanum) with different absorbances of the model phase-change material, Rubitherm RT22, was tested. DSC analysis elucidated several thermal properties (such as enthalpy, phase transition temperature, and temperature peak) of those mixtures and the results were compared with a commercial equivalent, Micronal DS 5040 X. Comparative research, approximating realistic conditions, were also performed by cooling and heating samples in a form of coatings that were made from chars with different content of RT22. These results indicated that the use of char as a PCM carrier was not only possible, but also beneficial from a thermodynamic point of view and it could serve as an alternative to commercial products. In this case, adsorption RT22 into char allowed for temperature stabilization comparable to Micronal DS 5040 X with ease of use as well as the economic advantages of being very low cost to produce due to microencapsulation. Other advantage of the proposed solution is related with the application of char obtained from waste biomass pyrolysis as a PCM carrier, and using this product in building construction to improve thermal comfort and increase energy efficiency. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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17 pages, 9215 KiB

Open AccessArticle

Using Eco-Friendly Recycled Powder from CDW to Prepare Strain Hardening Cementitious Composites (SHCC) and Properties Determination

by Wan Wang, Huixia Wu, Zhiming Ma and Ruixue Wu

Materials 2020, 13(5), 1143; https://doi.org/10.3390/ma13051143 - 4 Mar 2020

Cited by 16 | Viewed by 3496

Abstract

Using eco-friendly recycled brick powder (RBP) derived from waste brick to prepare strain hardening cementitious composites (SHCC) provides a new way of recycling the construction and demolition waste (CDW), and the dosage of cement in SHCC can be decreased. This paper investigated the [...] Read more.

Using eco-friendly recycled brick powder (RBP) derived from waste brick to prepare strain hardening cementitious composites (SHCC) provides a new way of recycling the construction and demolition waste (CDW), and the dosage of cement in SHCC can be decreased. This paper investigated the micro-properties and mechanical properties of SHCC containing RBP by a series of experiments. The results showed that RBP had typical characteristics of supplementary cementitious material (SCM). The addition of RBP increased the SiO₂ content and decreased the hydration products in cementitious materials; in this case, the mechanical properties of mortar decreased with increasing RBP replacements, and a linear relationship was observed between them. It was noticed that the adverse effect of RBP on the mechanical properties decreased with increasing PVA fiber content in mortar. For SHCC containing various RBP replacements, the ultimate load increased, and the ultimate displacement decreased with increasing curing days. When using RBP to replace cement by weight, the ultimate displacement increased with the addition of RBP. Meanwhile, there was no significant reduction in the ultimate load of SHCC. When using RBP to replace fly ash (FA) by weight, the incorporation of RBP decreased the ultimate displacement of SHCC, whereas the ultimate load was improved. For example, the ultimate load and displacement of SHCC with 54%RBP were 17.6% higher and 16.4% lower, respectively, than those of SHCC with 54% FA. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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14 pages, 38536 KiB

Open AccessArticle

An Experimental Study on Water Permeability of Architectural Mortar Using Waste Glass as Fine Aggregate

by Guoqing Jing, Gang Huang and Wenjun Zhu

Materials 2020, 13(5), 1110; https://doi.org/10.3390/ma13051110 - 2 Mar 2020

Cited by 9 | Viewed by 2936

Abstract

This paper investigates the water permeability, consistency and density of architectural mortar with various contents of glass sand as fine aggregate. To reduce the effect of alkali-silica-reaction (ASR), metakaolin (MK) was used as supplementary cementitious material (SCM) instead of a component of white [...] Read more.

This paper investigates the water permeability, consistency and density of architectural mortar with various contents of glass sand as fine aggregate. To reduce the effect of alkali-silica-reaction (ASR), metakaolin (MK) was used as supplementary cementitious material (SCM) instead of a component of white cement. The microstructure of glass sand mortar was visualized by means of scanning electron microscope (SEM) images. The experimental results showed that the permeability of the mortar increased with the glass sand, reaching its maximum at about 60–80% glass sand content. The optimum MK content varied with the content of glass sand, and higher content of MK was required for 60% glass sand. In addition, the consistency and density of mortar had a negative correlation with the increase of glass sand. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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12 pages, 4385 KiB

Open AccessArticle

Recycled Glass as a Substitute for Quartz Sand in Silicate Products

by Katarzyna Borek, Przemysław Czapik and Ryszard Dachowski

Materials 2020, 13(5), 1030; https://doi.org/10.3390/ma13051030 - 25 Feb 2020

Cited by 18 | Viewed by 4962

Abstract

In 2016, an average of 5.0 tons of waste per household was generated in the European Union (including waste glass). In the same year, 45.7% of the waste glass in the EU was recycled. The incorporation of recycled waste glass in building materials, [...] Read more.

In 2016, an average of 5.0 tons of waste per household was generated in the European Union (including waste glass). In the same year, 45.7% of the waste glass in the EU was recycled. The incorporation of recycled waste glass in building materials, i.e., concrete, cements, or ceramics, is very popular around the world because of the environmental problems and costs connected with their disposal and recycling. A less known solution, however, is using the waste glass in composite products, including sand-lime. The aim of this work was to assess the role of recycled container waste glass in a sand-lime mix. The waste was used as a substitute for the quartz sand. To verify the suitability of recycled glass for the production of sand-lime products, the physical and mechanical properties of sand-lime specimens were examined. Four series of specimens were made: 0%, 33%, 66%, and 100% of recycled waste glass (RG) as a sand (FA) replacement. The binder mass did not change (8%). The research results showed that ternary mixtures of lime, sand, and recycled waste glass had a higher compressive strength and lower density compared to the reference specimen. The sand-lime specimen containing 100% (RG) increased the compressive strength by 287% compared to that of the control specimen. The increase in the parameters was proportional to the amount of the replacement in the mixtures. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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21 pages, 5591 KiB

Open AccessArticle

Compressive Behavior of Circular Sawdust-Reinforced Ice-Filled Flax FRP Tubular Short Columns

by Yanlei Wang, Guipeng Chen, Baolin Wan and Baoguo Han

Materials 2020, 13(4), 957; https://doi.org/10.3390/ma13040957 - 20 Feb 2020

Cited by 12 | Viewed by 2989

Abstract

Sawdust-reinforced ice-filled flax fiber-reinforced polymer (FRP) tubular (SIFFT) columns are newly proposed to be used as structural components in cold areas. A SIFFT column is composed of an external flax FRP tube filled with sawdust-reinforced ice. The compressive behavior of circular SIFFT short [...] Read more.

Sawdust-reinforced ice-filled flax fiber-reinforced polymer (FRP) tubular (SIFFT) columns are newly proposed to be used as structural components in cold areas. A SIFFT column is composed of an external flax FRP tube filled with sawdust-reinforced ice. The compressive behavior of circular SIFFT short columns was systematically investigated. Four types of short columns with circular sections, including three plain ice specimens, three sawdust-reinforced ice specimens (a mixture of 14% sawdust and 86% ice in weight), nine plain ice-filled flax FRP tubular (PIFFT) specimens and nine SIFFT specimens, were tested to assess the concept of the innovative composite columns. The test variables were the thickness of flax FRP tubes and the type of ice cores. The test results indicated that the lateral dilation and the development of cracks of the ice cores were effectively suppressed by outer flax FRP tubes, thus causing a considerable enhancement in the compressive strength. Moreover, the compressive behavior, energy-absorption capacity, and anti-melting property of sawdust-reinforced ice cores were better than those of plain ice cores confined by flax FRP tubes with the same thicknesses. The proposed equations for estimating ultimate bearing capacities of PIFFT and SIFFT short columns were shown to provide reasonable and accurate predictions. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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10 pages, 4440 KiB

Open AccessArticle

Compressive Strength, Chloride Ion Penetrability, and Carbonation Characteristic of Concrete with Mixed Slag Aggregate

by Se-Jin Choi, Young-Uk Kim, Tae-Gue Oh and Bong-Suk Cho

Materials 2020, 13(4), 940; https://doi.org/10.3390/ma13040940 - 20 Feb 2020

Cited by 15 | Viewed by 2584

Abstract

The shortage of natural aggregates has recently emerged as a serious problem owing to the tremendous growth of the concrete industry. Consequently, the social interest in identifying aggregate materials as alternatives to natural aggregates has increased. In South Korea’s growing steel industry, a [...] Read more.

The shortage of natural aggregates has recently emerged as a serious problem owing to the tremendous growth of the concrete industry. Consequently, the social interest in identifying aggregate materials as alternatives to natural aggregates has increased. In South Korea’s growing steel industry, a large amount of steel slag is generated and discarded every year, thereby causing environmental pollution. In previous studies, steel slag, such as blast furnace slag (BFS), has been used as substitutes for concrete aggregates; however, few studies have been conducted on concrete containing both BFS and Ferronickel slag (FNS) as the fine aggregate. In this study, the compressive strength, chloride ion penetrability, and carbonation characteristic of concrete with both FNS and BFS were investigated. The mixed slag fine aggregate (MSFA) was used to replace 0, 25%, 50%, 75%, and 100% of the natural fine aggregate volume. From the test results, the highest compressive strength after 56 days was observed for the B/F100 sample. The 56 days chloride ion penetrability of the B/F75, and B/F100 samples with the MSFA contents of 75% and 100% were low level, approximately 34%, and 54% lower than that of the plain sample, respectively. In addition, the carbonation depth of the samples decreased with the increase in replacement ratio of MSFA. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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Review

Jump to: Editorial, Research

21 pages, 5828 KiB

Open AccessReview

Current Applications of Recycled Aggregates from Construction and Demolition: A Review

by Glaydson Simões dos Reis, Marco Quattrone, Weslei Monteiro Ambrós, Bogdan Grigore Cazacliu and Carlos Hoffmann Sampaio

Materials 2021, 14(7), 1700; https://doi.org/10.3390/ma14071700 - 30 Mar 2021

Cited by 87 | Viewed by 9792

Abstract

A literature review comprising 163 publications published over a period of 26 years from 1992 to 2018 is presented in this paper. This review discusses the generation and recycling of construction and demolition waste (CDW) as well as its main uses as raw [...] Read more.

A literature review comprising 163 publications published over a period of 26 years from 1992 to 2018 is presented in this paper. This review discusses the generation and recycling of construction and demolition waste (CDW) as well as its main uses as raw materials for the construction engineering sector. This review pays attention to the use of CDW aggregates for sand, pavements/roads, bricks, ceramics, cementitious materials, and concrete productions, as well its uses as eco-friendly materials for water decontamination. The physical-chemical and mechanical characteristics of recycled aggregates play an important role in their correctly chosen applications. The results found in this literature survey allow us to conclude that recycled aggregates from CDW can be successfully used to produce construction materials with quality comparable to those produced with natural aggregates. We concluded that the use of CDWs as raw materials for manufacturing new construction materials is technically feasible, economical, and constitutes an environmentally friendly approach for a future construction and demolition waste management strategy. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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15 pages, 2452 KiB

Open AccessReview

An Analytical Mini-Review on the Compression Strength of Rubberized Concrete as a Function of the Amount of Recycled Tires Crumb Rubber

by Luca Lavagna, Roberto Nisticò, Matteo Sarasso and Matteo Pavese

Materials 2020, 13(5), 1234; https://doi.org/10.3390/ma13051234 - 9 Mar 2020

Cited by 27 | Viewed by 4348

Abstract

Since waste tires constitute a serious environmental concern, several studies are devoted to the use of finely divided recycled rubber for the production of rubberized concrete by partial substitution of the mineral aggregate fraction. The introduction of rubber into concrete presents several advantages [...] Read more.

Since waste tires constitute a serious environmental concern, several studies are devoted to the use of finely divided recycled rubber for the production of rubberized concrete by partial substitution of the mineral aggregate fraction. The introduction of rubber into concrete presents several advantages (e.g., improvement of toughness and thermal/electrical/acoustic insulation capacities). Unfortunately, the addition of a high content of rubber into concrete causes an important loss of mechanical resistance of the final composite. In this context, several scientific studies are devoted to investigate the best technical solutions for favoring the interfacial adhesion between rubber and cement paste, but the interpretation of the literature is often misleading. To overcome this issue, the metadata extrapolated from the single scientific works were critically re-analyzed, forming reference diagrams where the variability fields of the different rubber concrete formulations (in terms of mechanical responses as a function of the rubber content) were defined and the best performances discussed. This study evidenced the twofold role of reference diagrams, able in both presenting the data in an unambiguous manner (for a successful comparison) and providing the guidelines for future works in this research field. Full article

(This article belongs to the Special Issue Recycled Materials for Concrete and Other Composites)

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