Buildings

Research

17 pages, 8667 KiB

Open AccessArticle

Microscopic Mechanism and Reagent Activation of Waste Glass Powder for Solidifying Soil

by Yuze Hong, Xinyi Xu, Chaojie Zhang, Zehai Cheng and Guanshe Yang

Buildings 2024, 14(5), 1443; https://doi.org/10.3390/buildings14051443 - 16 May 2024

Viewed by 864

Glass waste products represent a significant environmental concern, with an estimated 1.4 billion tons being landfilled globally and 200 million tons annually. This results in a significant use of land resources. Therefore, it would be highly advantageous to develop a new method for [...] Read more.

Glass waste products represent a significant environmental concern, with an estimated 1.4 billion tons being landfilled globally and 200 million tons annually. This results in a significant use of land resources. Therefore, it would be highly advantageous to develop a new method for disposing of waste glass. Waste glass can be recycled and ground into waste glass powder (WGP) for use in solidified soil applications as a sustainable resource. This study is based on solidified soil research, wherein NaOH, Ca(OH)₂, and Na₂SO₄ were incorporated as activators to enhance the reactivity of WGP. The optimal solidified soil group was determined based on unconfined compressive strength tests, which involved varying the activator concentrations and WGP content in combination with cement. X-ray diffraction (XRD) was used to study the composition of solidified soil samples. Microscopic pore characteristics were investigated using scanning electron microscopy (SEM), and the Image J software was employed to quantify the number and size of pores. Fourier-transform infrared spectroscopy (FTIR) was employed to examine the activation effect of waste glass powder. This study investigated the solidification mechanism and porosity changes. The results demonstrate that the addition of activated WGP to solidified soil enhances its strength, with a notable 12% increase in strength achieved using a 6% Ca(OH)₂ solution. The use of 2% concentration of Na₂SO₄ and NaOH also shows an increase in strength of 7.6% and 8.6%, respectively, compared to the sample without WGP. The XRD and SEM analyses indicate that activated WGP enhances the content of hydrates, reduces porosity, and fosters the formation of a more densely packed solidified soil structure. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

15 pages, 2555 KiB

Open AccessArticle

Experimental Study on the Mechanical Properties of Recycled Spiral Steel Fiber-Reinforced Rubber Concrete

by Jinqiu Yan, Yongtao Gao, Minggao Tang, Nansheng Ding, Qiang Xu, Man Peng and Hua Zhao

Buildings 2024, 14(4), 897; https://doi.org/10.3390/buildings14040897 - 26 Mar 2024

Cited by 1 | Viewed by 714

Abstract

Recycled rubber (RR) and recycled spiral steel fiber (RSSF) were added to plain concrete (PC) to prepare recycled spiral steel fiber rubber concrete (SSFRC) with matrix strengths of C30, C40, and C50. Strength tests on the PC, rubber concrete (RC), and SSFRC were [...] Read more.

Recycled rubber (RR) and recycled spiral steel fiber (RSSF) were added to plain concrete (PC) to prepare recycled spiral steel fiber rubber concrete (SSFRC) with matrix strengths of C30, C40, and C50. Strength tests on the PC, rubber concrete (RC), and SSFRC were carried out, including the cube compressive strength, splitting tensile strength, and flexural strength. The effects of RSSF and RR on the mechanical properties of concrete were analyzed. Simultaneously, the stress–strain curve of the SSFRC was obtained through axial compressive testing, and the toughness of SSFRC was evaluated by three indexes: the tensile compression ratio, bending compression ratio, and toughness index. The results show that adding RR to PC results in a decrease in the mechanical properties of concrete with different matrix strengths, and the addition of RSSF can make up for the strength loss of the rubber. The mechanical strength of SSFRC with different matrix strengths increased first and then decreased with the increase in RSSF content. The cubic compressive strength reached its peak value when the content of RSSF was 1%, and the splitting tensile strength and flexural strength reach their peak values when the content of RSSF was 1.5%. RSSF works best with rubber particles at the right dosage to further increase the toughness of the concrete. When the rubber content is 10%, and the RSSF content is 1.5%, the mechanical strength enhancement effect of SSFRC is at its best, and the toughness is also at its best. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

16 pages, 7406 KiB

Open AccessArticle

Sustainable Pavement Construction in Sensitive Environments: Low-Energy Asphalt with Local Waste Materials and Geomaterials

by Miguel A. Franesqui, Jorge Yepes and Samuel Valencia-Díaz

Buildings 2024, 14(2), 530; https://doi.org/10.3390/buildings14020530 - 16 Feb 2024

Cited by 2 | Viewed by 1451

Abstract

Low-energy asphalt techniques, such as warm mix asphalt (WMA), combined with the rational consumption of geomaterials and waste recycling would promote more sustainable and energy-efficient asphalt pavements. In volcanic environments, a significant proportion of aggregate production is discarded due to its extreme porosity, [...] Read more.

Low-energy asphalt techniques, such as warm mix asphalt (WMA), combined with the rational consumption of geomaterials and waste recycling would promote more sustainable and energy-efficient asphalt pavements. In volcanic environments, a significant proportion of aggregate production is discarded due to its extreme porosity, and used tires generate a main environmental issue as well. While recycled rubber powder from tire waste can enhance the mechanical behavior of asphalt, it also raises its viscosity. Therefore, joining rubberized asphalt containing local waste geomaterials with WMA technologies is crucial to reduce the manufacturing temperatures and emissions and to produce more eco-efficient pavements. For this purpose, the most relevant technological characteristics of rubberized warm mix asphalt with residual aggregates from highly vesiculated volcanic rocks are tested in the laboratory and contrasted with conventional mixtures. The outcomes demonstrate not only the feasibility of the production of such mixtures in line with the current specifications, but also show a significant improvement in the resistance to moisture and to plastic deformations, and an improvement in the stiffness modulus. The eco-efficiency indicators conclude that the energy consumption and emissions are reduced by 9%, enabling the reuse of waste materials by more than 95%. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

18 pages, 7174 KiB

Open AccessArticle

An Experimental Study on Innovative Concrete Block Solutions for Reconstruction

by Mahmut Cem Yılmaz, Ahmad Aswad and Ömer Mercimek

Buildings 2023, 13(10), 2667; https://doi.org/10.3390/buildings13102667 - 23 Oct 2023

Viewed by 2732

Abstract

In this study, an experiment was conducted to innovate a new design of interlocking concrete blocks (ICBs) containing recycled aggregates (RAs) by reducing the consumed time and cost in construction using an environmental approach. Accordingly, the designed ICBs were produced manually using RAs, [...] Read more.

In this study, an experiment was conducted to innovate a new design of interlocking concrete blocks (ICBs) containing recycled aggregates (RAs) by reducing the consumed time and cost in construction using an environmental approach. Accordingly, the designed ICBs were produced manually using RAs, and wallettes were easily built with a mortarless mechanism by stacking the blocks without any mortar layers. In the experiments, besides the individual compression tests of the two types of ICB with natural and recycled aggregates, the wallette samples that were produced using ICBs, containing either 100% natural aggregates or 100% Ras, were tested under axial compressive loading. The experimental results were assessed considering the compressive strength, displacement, and failure mode. In the obtained results, we noticed that the average compressive strengths of the wallettes that were produced with natural or recycled aggregate ICBs were large enough to meet the standards of Syrian regulations, which are considered an example reference. The resulting displacement values were acceptable and could be negligible in some wallette specimens. It was concluded that the innovative ICBs with both normal or recycled aggregates could be a good alternative to traditional blocks, especially in post-disaster or post-war areas. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

13 pages, 2834 KiB

Open AccessArticle

Effect of Crushing Method on the Properties of Produced Recycled Concrete Aggregates

by Julien Hubert, Zengfeng Zhao, Frédéric Michel and Luc Courard

Buildings 2023, 13(9), 2217; https://doi.org/10.3390/buildings13092217 - 31 Aug 2023

Cited by 4 | Viewed by 1907

Abstract

Construction and Demolition Waste (C&DW) is generated around the world and its quantity will increase in the future. Recycling has become the favored method of dealing with concrete waste but, to avoid its downcycling, it is important to develop a recycling process which [...] Read more.

Construction and Demolition Waste (C&DW) is generated around the world and its quantity will increase in the future. Recycling has become the favored method of dealing with concrete waste but, to avoid its downcycling, it is important to develop a recycling process which is able to produce high-grade recycled concrete aggregates (RCA). To that end, studying the influence of the production process on the properties of RCA can prove to be a crucial step toward a more circular construction industry. In this study, the influence of the crushing method is investigated. Samples of five laboratory-made concretes have been crushed using the most common mechanical crushing methods (impact crusher and jaw crusher), and the particle size distribution, morphology, hardened cement paste content and water absorption of the produced RCA have been measured and analyzed. The findings indicate that the use of impact crushers results in the production of RCA possessing more spherical geometric characteristics, albeit with a broader particle size distribution and a relatively higher content of fine particles as compared to those obtained from jaw crushers. Additionally, it is observed that the employed crushing technique seemingly exerts no discernible impact on the hardened cement paste content and the water absorption in the context of the studied concretes. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

13 pages, 3200 KiB

Open AccessArticle

Effect of Moisture Condition and the Composition of Aggregate from Demolition Waste on Strength and Workability Properties of Recycled Concrete

by Saied Kashkash, Oliver Czoboly and Zoltan Orban

Buildings 2023, 13(7), 1870; https://doi.org/10.3390/buildings13071870 - 23 Jul 2023

Cited by 3 | Viewed by 1576

Abstract

Large quantities of construction and demolition waste are generated annually, and in many parts of the world, it is disposed of in landfills. Utilizing this waste to produce coarse aggregates for concrete production offers a potentially sustainable approach that mitigates environmental impacts. Despite [...] Read more.

Large quantities of construction and demolition waste are generated annually, and in many parts of the world, it is disposed of in landfills. Utilizing this waste to produce coarse aggregates for concrete production offers a potentially sustainable approach that mitigates environmental impacts. Despite the widespread encouragement of using recycled aggregates as a substitute for natural coarse aggregates, practical applications remain limited, and the concrete production industry continues to primarily rely on exploiting natural resources. The recycling of concrete waste derived from the demolition of obsolete or damaged buildings as structural concrete has been seldom realized thus far, primarily due to regulatory constraints and concerns regarding technological difficulties. This paper presents a case study to demonstrate that, with meticulous preparation, concrete waste from a demolished building can be rendered suitable for use as structural concrete. The experimental investigation examined how the proportion of recycled aggregates obtained from a demolished building and the moisture content influenced the properties of fresh and hardened concrete. The results revealed an increase in the compressive strength of the hardened recycled concrete as a higher proportion of recycled coarse aggregate was incorporated into the mixture. Moreover, pre-soaked recycled coarse aggregates were found to improve the workability of the recycled concrete mixture significantly. The results highlight the significant potential of utilizing concrete waste as a valuable resource in the production of ready-mix concrete for structural applications, provided that appropriate measures are taken to optimize its properties. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

18 pages, 9145 KiB

Open AccessArticle

Stabilization of Shield Muck Treated with Calcium Carbide Slag–Fly Ash

by Jinzhe Wang, Ying Fan, Xixi Xiong and Fucai Zhao

Buildings 2023, 13(7), 1707; https://doi.org/10.3390/buildings13071707 - 4 Jul 2023

Cited by 8 | Viewed by 1714

Abstract

Solidifying shield muck with calcium carbide slag and fly ash as curing agents was proposed as a highly efficient method for reusing waste shield muck. The compaction test, unconfined compression test, and dry–wet cycle test were used to evaluate the compressive strength, water [...] Read more.

Solidifying shield muck with calcium carbide slag and fly ash as curing agents was proposed as a highly efficient method for reusing waste shield muck. The compaction test, unconfined compression test, and dry–wet cycle test were used to evaluate the compressive strength, water immersion stability, and durability of the cured soil. The stress–strain curve and microscopic test were employed to analyze the compression damage law, mineral composition, and microscopic morphology of the cured soil, and to analyze the mechanism of calcium carbide slag–fly ash-cured shield muck. It was found that calcium carbide slag–fly ash can significantly improve the compressive strength of shield muck, and the strength of cured soil increases and then decreases with an increase in calcium carbide slag and fly ash and increases with curing age. The strength was highest when the content of calcium carbide slag and fly ash was 10% and 15%, respectively. Dry–wet cycle tests showed that the specimens had good water immersion stability and durability, and the stress–strain curve of the specimen changed from strain hardening to strain softening after dry–wet cycles. The internal particles of the cured soil were mainly cemented and filled with C-(A)-S-H colloid and calcium alumina (AFt), which both support the pores between the soil and form a skeleton structure to enhance the strength of the soil and lend it good mechanical properties. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

13 pages, 3769 KiB

Open AccessArticle

Production of Large-Sized Ceramic Stones Based on Screenings from Waste Heap Processing Using the Technology of Stiff Extrusion for Molding Products

by Khungianos Yavruyan and Evgeniy Gaishun

Buildings 2023, 13(4), 845; https://doi.org/10.3390/buildings13040845 - 23 Mar 2023

Cited by 2 | Viewed by 1376

Abstract

This article discusses the prospects for using large-format ceramic stones in the construction of contemporary homes, as well as an overview of raw materials and technologies for production. The most promising technology is stiff extrusion with the ability to load the raw products [...] Read more.

This article discusses the prospects for using large-format ceramic stones in the construction of contemporary homes, as well as an overview of raw materials and technologies for production. The most promising technology is stiff extrusion with the ability to load the raw products on firing trolleys and accelerate the processes of firing and drying. Characteristics of Eastern Donbass waste heaps processing screenings are given, which are coal mining by-products and are considered to be main raw material for the production of large-sized ceramic stone. It is shown that as a result of introduction of waste heaps into the production of ceramic stones with the lowest prime cost, the density of the resulting products will be less than 800 kg/m³, the thermal conductivity will be less than 0.20 m·°C/W, and the strength grade will be M150 and higher. Thus, the use of ceramic stones in total volume of wall products for residential construction will reach the level of 80% and will increase the competitiveness of the material, especially when compared with gas silicate products, as used in Western Europe. High economic feasibility of the production of such materials based on by-products of waste heap processing is shown as well. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

17 pages, 11615 KiB

Open AccessArticle

Study on the Effect of Supplementary Cementitious Material on the Regeneration Performance of Waste Fresh Concrete

by Weicheng Wang, Daoming Zhang, Linqing Liu, Xueyuan Zhang and Yue Wang

Buildings 2023, 13(3), 687; https://doi.org/10.3390/buildings13030687 - 6 Mar 2023

Cited by 3 | Viewed by 1732

Abstract

In the preparation of ready-mixed concrete, it is inevitable to produce waste fresh concrete (WFC). An efficient, low-cost and environmentally friendly recycling scheme is the key to WFC recycling. In this work, we directly added some unhardened WFC to fresh concrete to prepare [...] Read more.

In the preparation of ready-mixed concrete, it is inevitable to produce waste fresh concrete (WFC). An efficient, low-cost and environmentally friendly recycling scheme is the key to WFC recycling. In this work, we directly added some unhardened WFC to fresh concrete to prepare recycled fresh concrete (RFC); on this basis, fly ash (FA) and nano-silica (NS) were added as supplementary cementitious material (SCM) to obtain modified recycled fresh concrete (RFC-SF). Then, the mechanical properties, slump, freeze–thaw resistance, phase structure of the hydration products and hydration process in RFC were studied. The results show that the addition of FA and NS significantly improved the comprehensive performance of RFC. Compared with RFC, the compressive strength of RFC-SF with 15% FA and 3% NS increased by 15.2% and 50.3% at 7 d and 90 d, respectively, and the splitting tensile strength increased by 20.5% and 76.4%, respectively. The slump remained above 155 mm, and the mass loss rate decreased by 42.6% after freeze–thaw cycles. XRD and FTIR analysis showed that the addition of FA and NS accelerated the hydration reaction process of RFC-SF, reduced the content of calcium hydroxide (CH) and refined the grain size of CH. RFC-SF had a denser microstructure and a lower calcium-silicon ratio in SEM and EDS tests. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

15 pages, 35708 KiB

Open AccessArticle

Fresh and Hardened Properties of Cementitious Composites Incorporating Firebrick Powder from Construction and Demolition Waste

by Ozer Sevim, Erdinc H. Alakara and Selahattin Guzelkucuk

Buildings 2023, 13(1), 45; https://doi.org/10.3390/buildings13010045 - 25 Dec 2022

Cited by 9 | Viewed by 1956

Abstract

Firebricks are generally used in furnace basins where glass, ceramics, and cement are produced. Firebricks have an important place in construction and demolition waste (CDW). However, there is a limited understanding of the effects on fresh and hardened state properties of cementitious composites. [...] Read more.

Firebricks are generally used in furnace basins where glass, ceramics, and cement are produced. Firebricks have an important place in construction and demolition waste (CDW). However, there is a limited understanding of the effects on fresh and hardened state properties of cementitious composites. This study investigates the mechanical, physical, and microstructural properties of cementitious composites incorporating firebrick powder (FBP) from CDW. In this regard, the FBP was used at 5, 10, 15, 20, and 25% replacement ratio by weight of cement to produce cementitious composites. The consistency, setting characteristics, and 3, 7, and 28 days compressive and flexural strength tests of produced cementitious composites were performed. In addition, ultrasonic pulse velocity, water absorption, porosity, unit weight, and microstructure analysis of cementitious composites were conducted. As a result, the 28-day compressive strength of the cementitious composite mortars containing up to 10% firebrick powder remained above 42.5 MPa. The flow diameters increased significantly with the increase of the FBP. Therefore, it has been determined that the FBP can be used up to 10% in cementitious composites that require load-bearing properties. However, FBP might be used up to 25% in some cases. Using waste FBP instead of cement would reduce the amount of cement used and lower the cost of producing cementitious composites. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

12 pages, 3475 KiB

Open AccessArticle

Strength Properties of Cement-Solidified Dredged Sludge Affected by Curing Temperature

by Yupeng Cao, Jing Zhang, Zengfeng Zhao, Junxia Liu and Hui Lin

Buildings 2022, 12(11), 1889; https://doi.org/10.3390/buildings12111889 - 4 Nov 2022

Cited by 2 | Viewed by 1824

Abstract

In this study, unconfined compressive strength (q_u) tests were conducted to explore the coupling effect of organic matter content (3.7%, 7.7%, 10.7%, and 13.7%) and curing temperature (18 °C, 36 °C, 46 °C) on the development of early and mid-late [...] Read more.

In this study, unconfined compressive strength (q_u) tests were conducted to explore the coupling effect of organic matter content (3.7%, 7.7%, 10.7%, and 13.7%) and curing temperature (18 °C, 36 °C, 46 °C) on the development of early and mid-late strength of cement-solidified dredged sludge (cement-stabilized clay, or CSC). The microstructure of the CSC containing organic matter at different curing temperatures was also analyzed. The results show that q_u of CSC decreases with the increase in organic matter content (C_o). The strength growth rate of CSC in the mid-late stage (≥14 days) is small when C_o ≥ 7.7%, and it is difficult to increase this strength growth rate even if the curing temperature is increased up to 46 °C. There is a cement incorporation ratio threshold of 15% for q_u of CSC containing organic matter (C_o = 7.7%), which is not affected by curing temperature; increasing the cement incorporation ratio (to 20%) cannot increase q_u significantly. The CSC with high curing temperature has more hydration products and higher structural compactness, and it can obtain higher q_u in the early and mid-late stages. A high curing temperature can increase the early strength growth rate and shorten the curing age for CSC containing organic matter. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

17 pages, 7068 KiB

Open AccessArticle

The Early Age Hydration Products and Mechanical Properties of Cement Paste Containing GBFS under Steam Curing Condition

by Baoliang Li, Zhouyang Tang, Binbin Huo, Zejun Liu, Yongzhen Cheng, Baizhan Ding and Peng Zhang

Buildings 2022, 12(10), 1746; https://doi.org/10.3390/buildings12101746 - 20 Oct 2022

Cited by 6 | Viewed by 2257

Abstract

The hydration products and strength of cement pastes incorporated with ground blast furnace slag (GBFS) (0% and 20% replacement) have been investigated under steam curing condition (80 °C for 7 h and 7 d) in comparison with normal curing condition (moist curing for [...] Read more.

The hydration products and strength of cement pastes incorporated with ground blast furnace slag (GBFS) (0% and 20% replacement) have been investigated under steam curing condition (80 °C for 7 h and 7 d) in comparison with normal curing condition (moist curing for 28 d). The results show that, during the initial 80 °C steam curing for 7 h, in addition to the filler effect, GBFS is still involved in cement hydration. The abundant available Al phase and Mg phase in GBFS promote the formation of flake-like hydrotalcite, foil-like C-(A)-S-H gels, as well as equant grain-shaped C-(A)-S-H gels. Prolonging the steam curing time to 7 d further improves the formation of hydrogarnet. Since the formation of both hydrogarnet and hydrotalcite can consume the available Al, steam curing for 7 d seems to favor the formation of low Al C-(A)-S-H gels. In addition, due to the formation of a large amount of hydration products, the influence of 20% GBFS addition on the demolding strength of initial steam-cured cement mortar (80 °C for 7 h) is almost negligible. However, further extending the steam curing time to 7 d increases the strength gap between 20% GBFS blended cement mortar and pure cement mortar, and the related mechanism is discussed. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

17 pages, 17262 KiB

Open AccessArticle

Investigation on Dynamic Mechanical Properties of Recycled Concrete Aggregate under Split-Hopkinson Pressure Bar Impact Test

by Wenping Du, Caiqian Yang, Hans De Backer, Chen Li, Kai Ming, Honglei Zhang and Yong Pan

Buildings 2022, 12(7), 1055; https://doi.org/10.3390/buildings12071055 - 20 Jul 2022

Cited by 4 | Viewed by 2117

Abstract

The dynamic mechanical properties of recycled concrete (RC) and natural concrete (NC) were studied by impact tests and numerical simulation. The quasi-static tests were conducted by a servo-hydraulic machine, while the impact test used a 50 mm diameter split-Hopkinson pressure bar (SHPB). The [...] Read more.

The dynamic mechanical properties of recycled concrete (RC) and natural concrete (NC) were studied by impact tests and numerical simulation. The quasi-static tests were conducted by a servo-hydraulic machine, while the impact test used a 50 mm diameter split-Hopkinson pressure bar (SHPB). The ANSYS/LS-DYNA software simulation was selected to validate the experimental results. The recycled coarse aggregates (RCAs) came from the housing demolition and were conducted with the microwave-assisted beneficiation method. The stress–strain curves, compressive strength, dynamic increase factor (DIF), initial elastic modulus and failure modes were analyzed and discussed. The results showed that the quasi-static compressive strengths of the RC were lower than that of the NC by 5.0%. The maximum dynamic compressive strengths of the NC increased by 105.9% when the strain rates varied from 46–108, while the RC increased by 102.2% when the strain rates varied from 42 to 103. The stress–strain curves of the RC and NC demonstrated a similar pattern. The DIF showed an increasing tendency with the increasing of strain rates, while the initial elastic modulus showed a decreasing tendency. The failure modes first initiated from the edge of specimens and then propagated to the center of specimens. An empirical equation was proposed for the estimation of the DIF of the RC which was obtained from the microwave-assisted beneficiation. The simulation results for the prediction of stress–strain curves of the RC showed good agreement with the experimental results. In addition, these results suggested that the RCAs were obtained by the microwave-assisted beneficiation can be recycled and may be used in some actual engineering. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

20 pages, 2966 KiB

Open AccessArticle

Partial Substitution of Binding Material by Bentonite Clay (BC) in Concrete: A Review

by Jawad Ahmad, Karolos J. Kontoleon, Mohammed Zuhear Al-Mulali, Saboor Shaik, Mohamed Hechmi El Ouni and Mohammed A. El-Shorbagy

Buildings 2022, 12(5), 634; https://doi.org/10.3390/buildings12050634 - 10 May 2022

Cited by 31 | Viewed by 5457

Abstract

Concrete consumes millions of tons of cement, which causes global warming as cement factories emit huge amounts of carbon dioxide into the atmosphere. Thus, it is essential to explore alternative materials as a substitute of OPC, which are eco-friendly and at the same [...] Read more.

Concrete consumes millions of tons of cement, which causes global warming as cement factories emit huge amounts of carbon dioxide into the atmosphere. Thus, it is essential to explore alternative materials as a substitute of OPC, which are eco-friendly and at the same time cost-effective. Although there are different options available to use industrial waste instead of cement, such as waste glass, waste marble, silica fume fly ash, or agriculture waste such as rice husk ash, wheat straw ash, etc., but bentonite clay is also one of the best options to be used as a binding material. There are a lot of diverse opinions regarding the use of bentonite clay as a cement substitute, but this knowledge is scattered, and no one can easily judge the suitability of bentonite clay as a binding material. Accordingly, a compressive review is essential to explore the suitability of bentonite clay as a cementitious material. This review focuses on the appropriateness of bentonite clay as a binding material in concrete production. The attention of this review is to discuss the physical and chemical composition of BC and the impact of BC on the fresh and mechanical performance of concrete. Furthermore, durability performance such as water absorption, acid resistance and dry shrinkage are also discussed. The results indicate that bentonite clay increased the mechanical and durability performance of concrete up to some extent but decrease its flowability. The optimum proportion of bentonite clay varies from 15 to 20% depending on the source of bentonite clay. The overall study demonstrates that bentonite clay has the creditability to be utilized partially instead of cement in concrete. Full article

(This article belongs to the Special Issue Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Sustainable Development: Recycle and Reuse of Waste Materials in Construction Industry

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Related Special Issue

Published Papers (14 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI