Sustainable Building Materials

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Buildings buildings	3.1	3.4	2011	15.3 Days	CHF 2600	Submit
Materials materials	3.1	5.8	2008	13.9 Days	CHF 2600	Submit
Recycling recycling	4.6	6.8	2016	20.9 Days	CHF 1800	Submit
Sustainability sustainability	3.3	6.8	2009	19.7 Days	CHF 2400	Submit

19 pages, 3366 KiB

Open AccessArticle

Soil Improvement Using Plastic Waste–Cement Mixture to Control Swelling and Compressibility of Clay Soils

by Mousa Attom, Sameer Al-Asheh, Mohammad Yamin, Ramesh Vandanapu, Naser Al-Lozi, Ahmed Khalil and Ahmed Eltayeb

Buildings 2025, 15(8), 1387; https://doi.org/10.3390/buildings15081387 - 21 Apr 2025

Abstract

Clay soils are known to have a high swelling pressure with an increase in water content. This behavior is considered a serious hazard to structures built upon them. Various mechanical and chemical treatments have historically been used to stabilize the swelling behavior of [...] Read more.

Clay soils are known to have a high swelling pressure with an increase in water content. This behavior is considered a serious hazard to structures built upon them. Various mechanical and chemical treatments have historically been used to stabilize the swelling behavior of clay soils. This work investigates the potential use of shredded plastic waste to reduce the swelling pressure and compressibility of clay soils. Two types of highly plastic clay (CH) soils were selected. Three different dimensions of plastic waste pieces were used, namely lengths of 0.5 cm, 1.0 cm, and 1.5 cm, with a width of 1 mm. A blend of plastic–cement waste with a ratio of 1:5 by weight was prepared. Different fractions of the plastic–cement waste blend with a 2 wt.% increment were added to the clay soil, which was then remolded in a consolidometer ring at 95% relative compaction and 3.0% below the optimum. The zero swell test, as per ASTM D4546, was conducted on the remolded soil samples after three curing periods: 1, 2, and 7 days. This method ensures the accurate evaluation of swell potential and stabilization efficiency over time. The experimental results showed that the addition of 6.0–8.0% of the blend significantly reduced the swelling pressure, demonstrating the mixture’s effectiveness in soil stabilization. It also reduced the swell potential of the expansive clay soil and had a substantial effect on the reduction in its compressibility, especially with a higher aspect ratio. The compression index decreased, while the maximum past pressure increased with a higher plastic–cement ratio. The 7-day curing time is the optimum time to stabilize expansive clay soils with the plastic–cement waste mixture. This study provides strong evidence that plastic waste can enhance soil mechanical properties, making it a viable geotechnical solution. Full article

(This article belongs to the Topic Sustainable Building Materials)

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22 pages, 3629 KiB

Open AccessReview

Replacing Sand in Concrete: Review on Potential for Utilization of Bottom Ash from Combustion of Wood in Circulating Fluidized Bed Boilers

by Anders Hedegaard Jensen, Carola K. Edvardsen and Lisbeth M. Ottosen

Recycling 2025, 10(2), 73; https://doi.org/10.3390/recycling10020073 - 14 Apr 2025

Viewed by 265

Abstract

Aggregates such as sand and gravel are the most mined resources on Earth and are the largest component in concrete. They are essential for construction but are becoming increasingly scarce. At the same time, large amounts of biomass ashes are produced in wood-fired [...] Read more.

Aggregates such as sand and gravel are the most mined resources on Earth and are the largest component in concrete. They are essential for construction but are becoming increasingly scarce. At the same time, large amounts of biomass ashes are produced in wood-fired power plants, offering potential as a partial substitute for decreasing sand resources. Due to the combustion technology of circulating fluidized bed boilers, their bottom ash offers high potential as a viable alternative to natural sand. This review examines previous research to assess the feasibility of replacing sand in concrete with bottom ash. Specific cementitious products are identified, where the substitution could realistically be performed in the concrete industry. Benefits and issues with partial substitution of bottom ash from wood combustion are discussed, and gaps in the research regarding sand replacements with bottom ash, notably the durability of the resulting concrete, are shown. Bottom ash has positive properties relevant for use in mortar and concrete, both regarding physical and chemical properties. Although limited research exists in the field, several researchers have demonstrated promising results when substituting sand for bottom ash in mortars. For lower substitution levels, little effect on the fresh and hardened properties is found. Full article

(This article belongs to the Topic Sustainable Building Materials)

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10 pages, 2002 KiB

Open AccessCommunication

Effect of Organotin on Performance of Siloxane Materials for Surface Treatment of Cementitious Materials

by Kaiyue Huang, Ji Zhang, Yue Li and Hui Yang

Materials 2025, 18(7), 1626; https://doi.org/10.3390/ma18071626 - 2 Apr 2025

Viewed by 216

Abstract

Surface treatment is essential for cementitious materials. Siloxane is a material that can potentially be applied in surface treatment, as it possesses the advantages of both inorganic and organic surface treatment materials for cement. Organotin, serving as a neutral catalyst, performs well in [...] Read more.

Surface treatment is essential for cementitious materials. Siloxane is a material that can potentially be applied in surface treatment, as it possesses the advantages of both inorganic and organic surface treatment materials for cement. Organotin, serving as a neutral catalyst, performs well in improving the performance of siloxane coating. In this work, the effect of organotin on the surface treatment performance of siloxane was studied for application in cementitious materials, including surface hardness and waterproofing properties. Organotin had little effect on the waterproofing of cement paste treated with siloxane. However, the addition of organotin positively impacted the surface hardness of cement paste treated with MTMS, which increased by 105.1%. The function of organotin was analyzed through XRD, FTIR, SEM, and pore structure characterizations. Organotin can speed up the gelation of siloxane, thus consuming more portlandite in cement. The negative effect of the alkyl group could be partially reduced by promoting the condensation of the alkoxy group. This indicated that treating siloxane with organotin is valuable for improving the durability of cement-based materials, increasing their surface hardness without affecting waterproofing. Full article

(This article belongs to the Topic Sustainable Building Materials)

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36 pages, 5908 KiB

Open AccessReview

Improving the Sustainability of Reinforced Concrete Structures Through the Adoption of Eco-Friendly Flooring Systems

by Chia Paknahad, Mosleh Tohidi and Ali Bahadori-Jahromi

Sustainability 2025, 17(7), 2915; https://doi.org/10.3390/su17072915 - 25 Mar 2025

Viewed by 626

Abstract

Following World War II, the swift economic growth in construction and the soaring demand in urban regions led to the excessive extraction of natural resources like fossil fuels, minerals, forests and land. To tackle significant global challenges, including the consumption of natural resources, [...] Read more.

Following World War II, the swift economic growth in construction and the soaring demand in urban regions led to the excessive extraction of natural resources like fossil fuels, minerals, forests and land. To tackle significant global challenges, including the consumption of natural resources, air pollution and climate change, radical changes have been suggested over the past decades. As part of this strategic initiative, prioritizing sustainability in construction has emerged as a crucial focus in the design of all projects. In order to identify the most environmentally sustainable reinforced concrete (RC) slab system, this research investigates the carbon emissions associated with various slab systems, including solid, voided slabs and precast floor systems. The results demonstrate that beam and slab floor and solid slabs have the highest embodied carbon due to the significant use of concrete and related materials, whereas voided slabs and two-way joist floors exhibit lower carbon emissions. The results indicate that the two-way joist system is the most environmentally advantageous option. For precast floor systems, post-tensioned concrete and hollow-core slabs demonstrate the lowest embodied carbon levels. This research provides practical recommendations for architects and engineers aimed at enhancing sustainable design methodologies. It emphasizes the importance of incorporating low-carbon materials as well as pioneering flooring technologies in upcoming construction initiatives to support the achievement of global sustainability objectives. Full article

(This article belongs to the Topic Sustainable Building Materials)

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17 pages, 5964 KiB

Open AccessArticle

Recycling Decommissioned Wind Turbine Blades for Post-Disaster Housing Applications

by Cihan Turhan, Murat Durak, Yousif Abed Saleh Saleh and Alper Kalaycı

Recycling 2025, 10(2), 42; https://doi.org/10.3390/recycling10020042 - 12 Mar 2025

Viewed by 625

Abstract

The growing adoption of wind energy has resulted in an increasing number of decommissioned wind turbine blades, which pose significant disposal challenges due to their size, material composition, and environmental impact. Recycling these blades has thus become essential. To this aim, this study [...] Read more.

The growing adoption of wind energy has resulted in an increasing number of decommissioned wind turbine blades, which pose significant disposal challenges due to their size, material composition, and environmental impact. Recycling these blades has thus become essential. To this aim, this study explores the potential of using recycled wind turbine blades in post-disaster housing applications and examines the feasibility of re-purposing these durable composite materials to create robust, cost-effective, and sustainable building solutions for emergency housing. A case study of a post-earthquake relief camp in Hatay, Türkiye, affected by the 2023 earthquake, is used for analysis. First, the energy consumption of thirty traditional modular container-based post-disaster housing units is simulated with a dynamic building simulation tool. Then, the study introduces novel wind turbine blade-based housing (WTB-bH) designs developed using the same simulation tool. The energy consumption of these (WTB-bH) units is compared to that of traditional containers. The results indicate that using recycled wind turbine blades for housing not only contributes to waste reduction but also achieves 27.3% energy savings compared to conventional methods. The novelty of this study is in demonstrating the potential of recycled wind turbine blades to offer durable and resilient housing solutions in post-disaster situations and to advocate for integrating this recycling method into disaster recovery frameworks, highlighting its ability to enhance sustainability and resource efficiency in construction. Overall, the output of this study may help to present a compelling case for the innovative reuse of decommissioned wind turbine blades, providing an eco-friendly alternative to traditional waste disposal methods while addressing critical needs in post-disaster scenarios. Full article

(This article belongs to the Topic Sustainable Building Materials)

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28 pages, 9825 KiB

Open AccessArticle

Study on the Application and Deformation Characteristics of Construction Waste Recycled Materials in Highway Subgrade Engineering

by Yuan Mei, Hongping Lu, Xueyan Wang, Bingyu Zhou, Ziyang Liu and Lu Wang

Buildings 2025, 15(5), 835; https://doi.org/10.3390/buildings15050835 - 6 Mar 2025

Viewed by 532

Abstract

It is difficult to meet environmental requirements via the coarse treatment methods of landfilling and open-air storage of construction waste. At the same time, the consumption of building materials in highway engineering is enormous. Using construction waste as a filling material for proposed [...] Read more.

It is difficult to meet environmental requirements via the coarse treatment methods of landfilling and open-air storage of construction waste. At the same time, the consumption of building materials in highway engineering is enormous. Using construction waste as a filling material for proposed roads has become a research hotspot in recent years. This paper starts with basic performance tests of recycled construction waste materials, and then moves on to laboratory experiments conducted to obtain the road performance of the recycled materials, the testing of key indicators of post-construction filling quality of the roadbed, and analyses of the deformation pattern of roadbed filled with construction waste. Additionally, the ABAQUS finite element software was used to establish a numerical model for roadbed deformation and analyze the roadbed deformation under different compaction levels and vehicle load conditions. The experimental results show that the recycled material has a moisture content of 8.5%, water absorption of 11.73%, and an apparent density of 2.61 g/cm³, while the liquid limit of fine aggregates is 20% and the plasticity index is 5.4. Although the physical properties are slightly inferior to natural aggregates, its bearing ratio (25–55%) and low expansion characteristics meet the requirements for high-grade highway roadbed filling materials. The roadbed layer with a loose compaction of 250 mm, after eight passes of rolling, showed a settlement difference of less than 5 mm, with the loose compaction coefficient stabilizing between 1.15 and 1.20. Finite element simulations indicated that the total settlement of the roadbed stabilizes at 20–30 mm, and increasing the compaction level to 96% can reduce the settlement by 2–4%. Vehicle overload causes a positive correlation between the vertical displacement and shear stress in the base layer, suggesting the need to strengthen vehicle load control. The findings provide theoretical and technical support for the large-scale application of recycled construction waste materials in roadbed engineering. Full article

(This article belongs to the Topic Sustainable Building Materials)

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18 pages, 20161 KiB

Open AccessArticle

Utilization of Mill Scale Waste as Natural Fine Aggregate Replacement in Mortar: Evaluation of Physical, Mechanical, Durability, and Post-Fire Properties

by Apinun Siriwattanakarn, Ampol Wongsa, Nawapak Eua-Anant, Vanchai Sata, Piti Sukontasukkul and Prinya Chindaprasirt

Recycling 2025, 10(1), 20; https://doi.org/10.3390/recycling10010020 - 5 Feb 2025

Viewed by 753

Abstract

The current paper presents the findings from experiments focused on using mill scale waste (MSW) as a natural fine aggregate (NFA) replacement in making cement mortar, aiming to recycle this material. Mortars were prepared by mixing with ordinary Portland cement, NFA, and water. [...] Read more.

The current paper presents the findings from experiments focused on using mill scale waste (MSW) as a natural fine aggregate (NFA) replacement in making cement mortar, aiming to recycle this material. Mortars were prepared by mixing with ordinary Portland cement, NFA, and water. NFA was replaced with 5%, 10%, 15%, and 20%vol of MSW. The physical and mechanical properties of mortars including compressive and flexural strengths, density, porosity, water absorption, ultrasonic pulse velocity, thermal conductivity, durability properties, and characteristics after being subjected to elevated temperatures at 400, 700, and 1000 °C were investigated after 28 days of curing. The results showed that 15% MSW exhibited optimum compressive and flexural strengths. Also, the MSW mortar showed reduced workability and thermal conductivity, while the porosity slightly increased. The addition of MSW enhanced chloride resistance and mortar’s residual compressive strength after exposure to various temperatures. These findings confirmed that MSW can be used as a sustainable fine aggregate to produce mortar with optimum physical, mechanical, durability, and post-fire properties. Full article

(This article belongs to the Topic Sustainable Building Materials)

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20 pages, 4464 KiB

Open AccessReview

Recycling Water Hyacinth as Supplementary Cementitious Material, Admixture, and Fiber in Mortar and Concrete: Current Trends and Research Gaps

by Gilberto García, René Cabrera, Julio Rolón and Roberto Pichardo

Recycling 2025, 10(1), 18; https://doi.org/10.3390/recycling10010018 - 4 Feb 2025

Viewed by 1922

Abstract

This review explores the potential of water hyacinth (WH) as a sustainable material in cement-based applications, focusing on its use as an addition, admixture, and fiber reinforcement. WH’s unique physical and chemical properties, such as high cellulose content and pozzolanic potential, make it [...] Read more.

This review explores the potential of water hyacinth (WH) as a sustainable material in cement-based applications, focusing on its use as an addition, admixture, and fiber reinforcement. WH’s unique physical and chemical properties, such as high cellulose content and pozzolanic potential, make it suitable for bio-composites and eco-friendly concrete formulations. The present study highlights several promising findings, including the enhancement of the resulting mechanical properties and the reduction in their environmental impact when the WH is incorporated in controlled quantities. Challenges such as workability and durability issues at higher dosages are discussed. This review aims to bridge knowledge gaps and support WH’s adoption in sustainable construction practices. Full article

(This article belongs to the Topic Sustainable Building Materials)

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14 pages, 4382 KiB

Open AccessArticle

Research on the Strength Characteristics of Red Soil Amended by Biochar

by Ke Li, Yu Xu, Yang Tan, Xianxiong Cai, Zhikui Liu and Qinxue Xu

Sustainability 2025, 17(3), 1174; https://doi.org/10.3390/su17031174 - 31 Jan 2025

Viewed by 735

Abstract

In order to investigate the effect of biochar on the strength characteristics of red loam, a number of experiments were carried out in the red loam of northern Guangxi Province, including a direct shear test, a scanning electron microscopy (SEM) test, and an [...] Read more.

In order to investigate the effect of biochar on the strength characteristics of red loam, a number of experiments were carried out in the red loam of northern Guangxi Province, including a direct shear test, a scanning electron microscopy (SEM) test, and an X-ray diffraction (XRD) test of red loam, bagasse biochar–red loam, and rice platycodon biochar–red loam. The aim of this study was to determine the effects of different biochar contents, types, and particle size ranges on the shear strength of the improved soils. The results showed that both bagasse biochar and rice platycodon biochar could effectively improve the shear strength of soil, and the shear strength increased first and then decreased with the increase in biochar content and reached the peak value when the content of biochar reached 6%. Under vertical pressures of 100 kPa, 200 kPa, 300 kPa, and 400 kPa, the shear strength of the two improved soils increased by 53.39%, 52.52%, 43.43%, and 47.08%, respectively, and 54.56%, 23.89%, 33.71%, and 47.78%, respectively, compared with that of plain soil. In addition, the grain size was negatively correlated with the shear strength, and the shear strength of the sample increased with a decrease in the grain size, in which the biochar in the range of 0~0.5 mm had the best effect on the strength improvement of the red loam. The results of this study provide theoretical and technical support for revealing the evolutionary mechanism of red loam strength and coping with soil erosion in red soil areas. Full article

(This article belongs to the Topic Sustainable Building Materials)

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17 pages, 2626 KiB

Open AccessArticle

From Waste to Resource: Evaluation of the Technical and Environmental Performance of Concrete Blocks Made from Iron Ore Tailings

by Luciana Chaves Weba, Júlia Maria Medalha Resende Oliveira, Alberto José Corrêa de Souza, Ludimila Gomes Antunes, José Maria Franco de Carvalho and Wanna Carvalho Fontes

Sustainability 2025, 17(2), 552; https://doi.org/10.3390/su17020552 - 13 Jan 2025

Viewed by 843

Abstract

This study investigates the use of iron ore tailings (IOTs) as recycled aggregates in segmental blocks, focusing on technical performance, CO₂ emissions, and embodied energy using the cradle-to-gate approach. IOTs replaced fine aggregates in concrete at 25%, 50%, and 75% by volume, [...] Read more.

This study investigates the use of iron ore tailings (IOTs) as recycled aggregates in segmental blocks, focusing on technical performance, CO₂ emissions, and embodied energy using the cradle-to-gate approach. IOTs replaced fine aggregates in concrete at 25%, 50%, and 75% by volume, achieving compressive strengths of 16.23 MPa, 10.02 MPa, and 3.93 MPa, respectively. Raw material production accounted for 98% of CO₂ emissions and 86% of embodied energy. Producing blocks at mining sites offered limited environmental benefits due to longer transport distances. Despite this, the results showed a 6% reduction in CO₂ emissions and a 35% improvement in mechanical–environmental performance (CO₂ emissions weighted by compressive strength) compared to traditional concrete. These findings underscore the potential of IOT-based concrete for segmental block production. Full article

(This article belongs to the Topic Sustainable Building Materials)

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19 pages, 4996 KiB

Open AccessArticle

Experimental Study on the Size Effect of Compression-Shear Fracture Characteristics of Rock-like Materials Containing Open Cracks

by Zixuan Li, Shiyuan Huang, Chuan Lv, Cheng Liao, Xudong Li and Hongbo Du

Materials 2024, 17(23), 5941; https://doi.org/10.3390/ma17235941 - 4 Dec 2024

Cited by 1 | Viewed by 722

Abstract

Understanding fracture mechanics in rock-like materials under compression-shear condition is critical for predicting failure mechanisms in various engineering applications, such as mining and civil infrastructure. This study conducted uniaxial compression tests on cubic gypsum specimens of varying sizes (side lengths of 75 mm, [...] Read more.

Understanding fracture mechanics in rock-like materials under compression-shear condition is critical for predicting failure mechanisms in various engineering applications, such as mining and civil infrastructure. This study conducted uniaxial compression tests on cubic gypsum specimens of varying sizes (side lengths of 75 mm, 100 mm, 125 mm, and 150 mm) and crack inclination angles (ranging from 0° to 90°) to assess the size effect on fracture behavior. The effects of specimen size and crack inclination on fracture characteristics, including strength, failure mode, and crack initiation angle, were analyzed based on the maximum tangential stress (MTS) criterion and the generalized maximum tangential stress (GMTS) criterion, with relative critical size (α) and relative openness (η). Results indicate that the crack initiation angle increases with crack inclination, while compressive strength decreases significantly with increasing specimen size. For example, at a 30° crack inclination, the peak compressive strength of 75 mm specimens was 2.53 MPa, whereas that of 150 mm specimens decreased to 1.05 MPa. Crack type and failure mode were found to be primarily influenced by crack inclination rather than specimen size. The experimental crack initiation angle aligned with the theoretical crack initiation angle at inclinations below 50° but diverged at higher inclinations. A linear relationship was established between r_c and specimen size (L) under compression-shear stress, expressed as

r_{c} = - 0.01772 L + 3.54648

; larger specimens exhibited increased tangential stress at the crack tip, leading to earlier macroscopic crack formation, while r_c decreased as specimen size increased. These results underscore the significant influence of size on fracture behavior in quasi-brittle materials under compression-shear stress, providing essential insights for predicting material failure in rock-like structures. Full article

(This article belongs to the Topic Sustainable Building Materials)

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13 pages, 4273 KiB

Open AccessArticle

Production of a Wood–Plastic Composite with Wastes from Disposable Masks and Corrugated Cardboard: A Sustainable Post-Pandemic Approach

by Anderson Ravik dos Santos, Rivelino Neri Silva, Nayara Mendes dos Santos, Mariana Fernandes Costa Vieira, Patrícia Santiago de Oliveira Patrício and Wanna Carvalho Fontes

Sustainability 2024, 16(22), 9726; https://doi.org/10.3390/su16229726 - 8 Nov 2024

Cited by 1 | Viewed by 1911

Abstract

The increasing demand for disposable textile products, personal care items, and electronic commerce has led to a substantial rise in waste generation, particularly from nonwoven fabric masks (wNWFs) and corrugated cardboard (wCC). This study assessed the feasibility of utilizing these waste materials, which [...] Read more.

The increasing demand for disposable textile products, personal care items, and electronic commerce has led to a substantial rise in waste generation, particularly from nonwoven fabric masks (wNWFs) and corrugated cardboard (wCC). This study assessed the feasibility of utilizing these waste materials, which were produced in significant amounts during the COVID-19 pandemic, as both a matrix and reinforcement filler in wood–plastic composites (WPCs). The WPC was fabricated using either two extrusion cycles or thermokinetic homogenization, with both processes being followed by hot pressing. The formulations consisted of virgin polypropylene (vPP), wNWF, and wCC in proportions of 45, 45, and 10 wt %, respectively. The results demonstrated that the composites produced via two extrusion cycles exhibited a tensile strength that was 85% higher and three-point flexural strength three times greater than those produced through thermokinetic homogenization. These findings contribute to advancements in scientific and technological knowledge and offer an efficient solution for managing these types of waste, which continue to be generated post-pandemic. Full article

(This article belongs to the Topic Sustainable Building Materials)

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16 pages, 20185 KiB

Open AccessArticle

Study on the Improvement Performance of Different Clay Components with Desulfurization Gypsum-Containing Cementitious Material

by Tingzhu Chen, Xin Dong, Hongxu Chen, Feng Zhou, Gang Liu, Wei Chang and Rui Zhu

Buildings 2024, 14(10), 3274; https://doi.org/10.3390/buildings14103274 - 16 Oct 2024

Cited by 2 | Viewed by 972

Abstract

The use of cementitious materials to improve clay is a common technique in engineering. However, the effectiveness of these materials, particularly desulfurized gypsum, on clays with different mineral compositions remains unclear, resulting in a lack of theoretical basis for their application in engineering. [...] Read more.

The use of cementitious materials to improve clay is a common technique in engineering. However, the effectiveness of these materials, particularly desulfurized gypsum, on clays with different mineral compositions remains unclear, resulting in a lack of theoretical basis for their application in engineering. This study investigated the synergistic effects of clinker–metakaolin–desulfurized gypsum on clays with various mineral compositions through a series of macroscopic and microscopic laboratory tests. The results revealed that the stress–strain relationships of all clay samples exhibited softening characteristics. The softening was most pronounced in kaolinite samples, followed by illite and bentonite samples. For single-phase clays, the unconfined compressive strength followed the order of kaolinite > illite > bentonite. For multiphase clays, the order was illite + kaolinite > bentonite + illite + kaolinite > bentonite + kaolinite > bentonite + illite. The strength enhancement in the improved soils was primarily due to kaolinite and illite. As the content of desulfurized gypsum increased, the ettringite crystals in the improved soils transformed from cluster-like to framework-like structures. When the gypsum content exceeded 10%, the macroscopic performance of the improved soils decreased. These findings provide valuable insights for related engineering applications. Full article

(This article belongs to the Topic Sustainable Building Materials)

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13 pages, 5331 KiB

Open AccessArticle

Alkali Activation of Metakaolin and Wollastonite: Reducing Sodium Hydroxide Use and Enhancing Gel Formation through Carbonation

by Veronica Viola, Prince Allah, Priyadharshini Perumal and Michelina Catauro

Materials 2024, 17(19), 4910; https://doi.org/10.3390/ma17194910 - 8 Oct 2024

Cited by 1 | Viewed by 1132

Abstract

Alkali activated materials (AAMs) offer significant advantages over traditional materials like Portland cement, but require the use of strong alkaline solutions, which can have negative environmental impacts. This study investigates the synthesis of AAMs using metakaolin and wollastonite, aiming to reduce environmental impact [...] Read more.

Alkali activated materials (AAMs) offer significant advantages over traditional materials like Portland cement, but require the use of strong alkaline solutions, which can have negative environmental impacts. This study investigates the synthesis of AAMs using metakaolin and wollastonite, aiming to reduce environmental impact by eliminating sodium silicate and using only sodium hydroxide as an activator. The hypothesis is that wollastonite can provide the necessary silicon for the reaction, with calcium from wollastonite potentially balancing the negative charges usually countered by sodium in the alkaline solution. This study compares raw and carbonated wollastonite (AAM-W and AAM-CW) systems, with raw materials carefully characterized and binding networks analyzed using TGA, FT-IR, and XRD. The results show that while wollastonite can reduce the amount of sodium hydroxide needed, this reduction cannot exceed 50%, as higher substitution levels lead to an insufficiently alkaline environment for the reactions. The carbonation of wollastonite enhances the availability of silicon and calcium, promoting the formation of both N-A-S-H and C-A-S-H gels. Full article

(This article belongs to the Topic Sustainable Building Materials)

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13 pages, 7221 KiB

Open AccessArticle

Investigation of the Temperature and Horizontal Freezing Force of Loess in Three-Dimensional Freezing

by Yidan Yin, Fei Liu, Dongqi Tang, Longze Chen and Binbin Yang

Materials 2024, 17(18), 4614; https://doi.org/10.3390/ma17184614 - 20 Sep 2024

Viewed by 882

Abstract

Seasonal frozen soil has significant impacts on changes in soil mechanical properties, settlement, and damage to foundations. In order to study variations in the temperature and horizontal freezing force of loess during three-dimensional freezing, a three-dimensional freezing model test of loess was carried [...] Read more.

Seasonal frozen soil has significant impacts on changes in soil mechanical properties, settlement, and damage to foundations. In order to study variations in the temperature and horizontal freezing force of loess during three-dimensional freezing, a three-dimensional freezing model test of loess was carried out. This experiment analyzed and studied the soil temperature change distribution characteristics, horizontal freezing force distribution rules, and water migration phenomena caused by temperature. The research results show that the temperature change in soil samples exhibits a “ring-like” decrease from the outside to the inside. When the soil temperature reaches the supercooling point, the cooling curve jumps and rises, and this is accompanied by a stable section with constant temperature. In the late freezing period, the temperature rate drops slowly. Under the action of freezing, the horizontal freezing forces at different positions have similar change characteristics and can be divided into four change stages: stable stage, rapid freezing stage, “secondary” freezing stage, and freezing–shrinkage–rebound stable stage. At lower moisture contents, loess samples undergo freeze–thaw shrinkage during the freezing process. During the rapid freezing stage of soil samples, the water in the soil sample migrates and causes secondary freezing. After the rapid freezing stage, the soil temperature continues to decrease, and the horizontal freezing force no longer decreases. Full article

(This article belongs to the Topic Sustainable Building Materials)

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18 pages, 12388 KiB

Open AccessArticle

Factors Affecting the Physical Properties of Microbial Induced Calcium Carbonate Precipitation (MICP) Enhanced Recycled Aggregates

by Jin Zhang, Cong Wang and Zhipeng Wang

Buildings 2024, 14(9), 2851; https://doi.org/10.3390/buildings14092851 - 10 Sep 2024

Cited by 1 | Viewed by 1774

Abstract

Microbial-induced calcium carbonate precipitation (MICP) can enhance the physical properties of recycled aggregates. Compared to traditional technologies, MICP offers environmental benefits and produces no pollution. However, its mineralization efficacy is significantly influenced by the process parameters. To investigate this, an MICP mineralization test [...] Read more.

Microbial-induced calcium carbonate precipitation (MICP) can enhance the physical properties of recycled aggregates. Compared to traditional technologies, MICP offers environmental benefits and produces no pollution. However, its mineralization efficacy is significantly influenced by the process parameters. To investigate this, an MICP mineralization test was conducted by manipulating various process parameters throughout the mineralization process. The water absorption rate, apparent density, and calcium carbonate content of the mineralized recycled aggregates were assessed to discern the impact of these parameters on the mineralization outcome. Further analysis using techniques such as thermogravimetric analysis (TG), X-ray diffraction (XRD), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM) were employed to elucidate the mineralization mechanism of the recycled aggregates at a micro-level. The findings indicated that the MICP treatment induced bacteria to precipitate CaCO₃, forming calcite crystalline CaCO₃ within the pores and microcracks. This led to a denser interfacial transition zone and, consequently, improved the physical properties of the recycled aggregates. Optimal mineralization was achieved when the bacterial solution concentration was 1.4, the temperature and pH were 35 °C and 9, respectively, and the urea concentration, Ca⁺ concentration, and mineralization time were 0.5 mol/L, 0.5 mol/L, and 7 days, respectively. Under these conditions, the mineralized recycled aggregate exhibited a 16.07% reduction in water absorption, a 1.07% increase in apparent density, and a 2.28% change in mass. Full article

(This article belongs to the Topic Sustainable Building Materials)

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13 pages, 9941 KiB

Open AccessArticle

Non-Destructive Monitoring of Hydration Characteristics in Alternative Materials and Seawater-Based Cementitious Pastes Using Electrochemical Impedance Spectroscopy

by Fangsheng Gao, Lei Cheng, Jun Liu and Jihua Zhu

Sustainability 2024, 16(17), 7368; https://doi.org/10.3390/su16177368 - 27 Aug 2024

Cited by 2 | Viewed by 1037

Abstract

This study investigates the hydration behavior of cementitious materials incorporating fly ash, limestone and calcined clay (LC2), and seawater, aiming to understand the individual and synergistic effects of these components on hydration kinetics. The motivation behind this research lies in the growing interest [...] Read more.

This study investigates the hydration behavior of cementitious materials incorporating fly ash, limestone and calcined clay (LC2), and seawater, aiming to understand the individual and synergistic effects of these components on hydration kinetics. The motivation behind this research lies in the growing interest in enhancing the performance and sustainability of cement-based materials by incorporating supplementary materials and utilizing seawater. To achieve this, the hydration process was meticulously examined using electrochemical impedance spectroscopy (EIS). An innovative equivalent circuit model was developed to analyze the results. The experimental data indicated that, with ongoing hydration, the diameter of the impedance arc in the high-frequency range gradually increases. A noteworthy observation is that increasing the proportion of fly ash and LC2 in the cement paste leads to a corresponding enlargement of the high-frequency arc, indicating a significant influence of these supplementary materials on the hydration process. Additionally, LC2 was found to be more effective in accelerating the hydration process compared to fly ash. Full article

(This article belongs to the Topic Sustainable Building Materials)

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17 pages, 13539 KiB

Open AccessArticle

Investigation of the Impact of Geotextile Incorporation on the Mechanical Properties of Geopolymer

by Wei Zhou, Xiujie Zhang, Hongzhong Li, Rongtao Yan, Xianlun Huang, Jianjun Gan, Jinping Zhang, Xiaoyong Cheng, Junhong Yuan and Bingxiang Yuan

Buildings 2024, 14(9), 2595; https://doi.org/10.3390/buildings14092595 - 23 Aug 2024

Viewed by 1021

Abstract

Geopolymers assume an irreplaceable position in the engineering field on account of their numerous merits, such as durability and high temperature resistance. Nevertheless, geopolymers also demonstrate brittleness. In this study, geotextiles with different layers were added to geopolymer to study its compressive strength [...] Read more.

Geopolymers assume an irreplaceable position in the engineering field on account of their numerous merits, such as durability and high temperature resistance. Nevertheless, geopolymers also demonstrate brittleness. In this study, geotextiles with different layers were added to geopolymer to study its compressive strength and stability. Laboratory materials such as alkali activators, geotextiles and granite residual soil (GRS) were utilized. The samples were characterized via XRD, TG-DTG, SEM-EDS and FT-IR. The results indicate that the toughness of geopolymer is significantly enhanced by adding geotextiles, and the strength increase is most obvious when adding one layer of geotextile: the strength increased from 2.57 Mpa to 3.26 Mpa on the 14th day, an increase of 27%. Additionally, the D-W cycle has a great influence on geotextile polymers. On the 14th day, the average strength of the D-W cyclic sample (1.935 Mpa) was 1.305 Mpa smaller than that of the naturally cured sample (3.24 Mpa), and the strength decreased by 40%. These discoveries offer a novel approach for further promoting the application of geopolymers, especially in the field of foundation reinforcement. Full article

(This article belongs to the Topic Sustainable Building Materials)

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16 pages, 8344 KiB

Open AccessArticle

Deformation Effects of Deep Foundation Pit Excavation on Retaining Structures and Adjacent Subway Stations

by Zhijian Jiang, Shu Zhu, Xiangcheng Que and Xinliang Ge

Buildings 2024, 14(8), 2521; https://doi.org/10.3390/buildings14082521 - 15 Aug 2024

Cited by 8 | Viewed by 1594

Abstract

In complex underground conditions, the excavation of deep foundation pits has a significant impact on the deformation of retaining structures and nearby subway stations. To investigate the influence of deep excavation on the deformation of adjacent structures, a three-dimensional numerical model of the [...] Read more.

In complex underground conditions, the excavation of deep foundation pits has a significant impact on the deformation of retaining structures and nearby subway stations. To investigate the influence of deep excavation on the deformation of adjacent structures, a three-dimensional numerical model of the foundation pit, existing subway station, and tunnel structure was established using FLAC 3D software, based on the Shenzhen Bay Super Headquarters C Tower foundation pit project. The study analyzed the deformation characteristics of retaining structures, adjacent subway stations, and tunnels during different stages of deep excavation, and the accuracy of the numerical simulation results was validated through field monitoring data. The results indicate that during the excavation process of the foundation pit, the lateral horizontal displacement of the retaining structure is generally small, with a typical “concave inward” lateral deformation curve; the horizontal displacement value of the contiguous wall section is less than that of the interlocking pile section. The bending moments of the retaining structure show a distribution pattern with larger values in the middle and smaller values at the top and bottom of the pit, with a relatively uniform distribution of internal support forces. The maximum displacement of the nearby subway station is 8.75 mm, and the maximum displacement of the subway tunnel is 2.29 mm. The research findings can provide references for evaluating the impact of newly built foundation pits near subway stations and contribute to the rational design and safe construction of new projects. Full article

(This article belongs to the Topic Sustainable Building Materials)

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