Eco-friendly Building Materials Research Articles

Eco-friendly approach to construction: Incorporating waste plastic in geopolymer concrete

This study examines the outcomes of using recycled plastic in geopolymer concrete. In order to better understand how waste plastic affects the characteristics of geopolymer concrete, a sustainable alternative to conventional concrete, this research proposes to conduct a series of experiments. This study compiles findings from earlier investigations on the use of waste plastic in concrete as well as a literature review on geopolymer concrete. Experimental techniques include a description of the plastics used, how those plastics were selected, how samples were prepared, and how they were tested. Mechanical characteristics, workability, thermal properties, microstructure, and environmental effect of geopolymer concrete containing waste plastic are shown in the results and discussion section. The research found that geopolymer concrete's characteristics and performance were affected by the addition of waste plastic, which might have implications for the future of eco-friendly building materials. Optimal plastic composition, long-term behaviour evaluation, and application exploration need more study.

Strength and environmental evaluation of building bricks using industrial waste for liveable environments

Researchers around the world have been enthusiastically using industrial waste to develop eco-friendly building materials. The main objective of this study was to explore the potential of using local industrial waste, such as Solid Waste Fly Ash (SWFA) and Paint Sludge (PS), as alternative to non-renewable laterite soil. During the preliminary stage, compacted cylinders of two systems were investigated: Laterite Soil (LS) and SWFA at 50:50 ratio, and a combination of LS, SWFA and PS (LSP) at 50:25:25 ratio. Traditional stabilisers Hydrated Lime (HL) and Ordinary Portland Cement (OPC), as well as Ground Granulated Blastfurnace Slag (GGBS), were used at different ratios (10%, 20%, 30% and 40%) for these cylinders. The cylinders were cured for 7, 28 and 60 days prior to strength and water absorption test. The results showed that 30% stabiliser dosage provided the best strength and economic benefits. Based on these findings, pilot industrial and commercial trials were conducted using full-sized unfired bricks. The LSP brick system with the blended stabiliser HL-GGBS performed exceptionally well in terms of engineering properties. The investigation suggests that SWFA and Paint Sludge can be promising substitutes for clay in unfired bricks production, promoting waste recycling and reducing the impact of landfills. Using local available waste materials to manufacture unfired bricks present a viable alternative to fired bricks, especially in low-load bearing situations. This research contributes to innovation, enhanced waste management, and the concept of green building. Moreover, it minimizes energy usage and hazardous emissions associated with brick firing, aligning with the Sustainable Development Goals (SDGs).

Factor Analysis of the Physical–Mechanical Properties for Geopolymers Based on Brick Dust and Biomass Bottom Ash as Eco-Friendly Building Materials

The production of building materials is unavoidable if the well-being and development of society are to be maintained. However, in manufacturing these materials, significant greenhouse gas emissions and environmental effects are produced. For this reason, and with the aim of reducing the impact of the manufacture of these materials, this work developed a geopolymeric material made up solely of wastes, brick dust and biomass bottom ashes which replaced the traditional ceramic materials. To evaluate the quality of this sustainable geopolymeric material, different groups of specimens were formed with different percentages of both residues, subsequently determining the physical properties of the new-formed geopolymers and guaranteeing they accomplish the prescriptions of the ceramic regulations for construction. In addition, the results of the geopolymer characterisation tests were statistically analysed using factor analysis, with the sole purpose of establishing connections and interdependence between the variables that influence the geopolymerisation process. Thus, it was possible to demonstrate that the combination of brick dust and biomass bottom ashes produced geopolymers with adequate qualities to replace traditional ceramics, as well as that the different combinations of both residues produced feasible materials to be used as ceramics with various characteristics, with two main factors determined by factorial analysis that governed the physical properties of the geopolymer obtained: the percentage of brick dust and the theoretical porosity.

Green and Eco Friendly Building Materials (A case study on AAC Block on High rise building)

Green and Eco Friendly Building Materials (A case study on AAC Block on High rise building)

Feasibility of using Cr-containing vitrification product as cement admixture: Structural evolution and chromium immobilization

With China already committing to bring carbon dioxide emissions to a peak before 2030, reducing the amount of used cement is an economical and effective measure. In this study, chromium-containing vitrification products were used as a cement admixture to achieve chromium reduction and immobilization. This study presents the effect of MgO/B2O3/Cr2O3 on the relationship between the network structure and chemical resistance of a Cr-containing glass matrix. The acid/alkali resistance of the glass specimens improved with an increase in Cr2O3 content under the same matrix composition. With the replacement of CaO by MgO, the chemical resistance of boron-free glass specimens improved, while that of Mg/B-containing glass specimens significantly decreased. The behaviors of the glass matrix in chemical environments affected the hydration and chromium immobilization of cement clinkers. In paste specimens, the pozzolanic reaction of the glass powder enhanced the densification of specimens. The mechanical strength was attributed to the filling effect of pozzolanic gels and undissolved glass powder in the mortar samples. B-containing glass powder negatively affected the mechanical strength and chromium immobilization of cement samples, while an appropriate amount of MgO and Cr2O3 was beneficial to the physical and chemical properties of the material. Therefore, chromium-containing waste glass can be effectively used to produce eco-friendly building materials.

Bio-mechanical efficacy for slag/fly ash-based geopolymer mingled with mesoporous NiO

The main target of this research is the fabrication of pre-cast/self-cleaning eco-friendly building materials with adequate mechanical properties to be used in constructions exposed to bacteria, such as hospitals, to prevent the spread of epidemics and diseases. The impact of different doses of mesoporous NiO (MP-NiO) on the compressive strength value of 50 wt%slag+ 50 wt%fly-ash geopolymer paste was studied at different curing regimes. At 28-days of normal curing, the strength values for the modified pastes containing 0%, 0.5%, 1%, and 2% MP-NiO were 47, 62.4, 65.9 and 58.5 MPa, respectively, while these values completely changed under hydrothermal treatment to become 98.6, 104.8, 105.6 and 100.8 MPa, respectively at 6bars for 4hrs. XRD, TGA/DTG, and SEM techniques affirmed the dual effect of MP-NiO and hydrothermal curing in the production of CSHs, CAHs, CASHs, zeolitic phases, nickel-aluminate spinel (NiAl2O4) and calcium-nickel-silicate (CaNiSi2O6) that reinforced the internal microstructure. The self-cleaning test was conducted via the agar diffusion method. High bacterial resistivity was observed in the cases of discs containing 1% mesoporous NiO, whatever the curing conditions, as these discs strongly resisted the growth of Salmonella, K.Pneumonia, and E. Faecalis and the measured inhibition zones around normally cured discs were 44 ± 1, 44 ± 1, and 52 ± 2, respectively while the measured inhibition zones around autoclaved discs were 45 ± 1, 43 ± 1, and 48 ± 2, respectively.

Sustainable Eco-Friendly Building Material – A Review Towards Compressed Stabilized Earth Blocks and Fire Burnt Clay Bricks

The aim of the current research article is to provide a comprehensive review and discuss and conclude on two types of earth blocks i.e., stabilized compressed earth blocks and fire-burnt clay bricks. A direct correlation exists between the number of greenhouse gases emitted and the amount of coal used to manufacture the fire-burnt clay bricks. To address this issue, new construction materials have been developed. Compressed Stabilized Earth Blocks (CSEBs) is an enhanced earth-based masonry material as it is not burnt. CSEBs are manufactured by compressing the soil under pressure. Coal and other burning fuels are not used at any point in the manufacturing process of CSEBs. Environment-friendly and energy-efficient construction materials that encourage the sustainable development have grown significantly in the recent years, as the public have become highly conscious. Since the building materials are produced in local communities, the local resources are efficiently used, transportation costs get reduced and high-quality housing is made available to a large spectrum of people. Less time-consuming construction techniques and low labour demand results in increased strength, insulation and thermal characteristics, lower carbon emissions and embodied energy during the life cycle of the materials and exceptionally low levels of trash that can be easily disposed of. When locally-produced materials are used for building purposes, it creates jobs and is more eco-friendly, during the times of crisis. CSEB and conventional bricks require different amounts of energy and release significantly different amounts of carbon dioxide throughout the production process. A review of the construction process that utilizes clay bricks and CSEBs has been conducted using the data and reports from numerous research papers and organizations. According to this review, the Compressed Stabilized Earth Blocks outperform the fire-burnt clay bricks in terms of advantages. When it comes to creating new environment-friendly construction materials, the CSEBs remain a viable option.

Study on the mechanical and thermal properties of one-part geopolymer composite for high performance in energy piles

One-part geopolymer is a single-component, easy-to-use geopolymer material that offers simplified and cost-effective production processes for eco-friendly building materials. This study aimed to optimize the thermal and mechanical properties of one-part geopolymer for geothermal energy applications by incorporating both silicon carbide (SiC) sand and SiC powder. Various mix designs of one-part geopolymer composites were investigated, and their flexural and compressive strength were analysed. Thermal conductivity was measured using a novel home-made test set-up. Results showed that the compressive strength of one-part geopolymer composite can be as high as 83 MPa under ambient curing condition. The relationship between flexural and compressive strength was also studied, with the PCA code providing the best fitting precision. Furthermore, the thermal conductivity of one-part geopolymer composite was significantly increased with the combined application of SiC powder and SiC particles. These findings suggest that geopolymer composites with SiC materials are suitable for geothermal energy applications.

Optimization of plastic waste integration in cement bricks

Implementing plastic waste in construction materials is a sustainable disposal method to overcome plastic pollution. The current study aims to optimize the integration of plastic waste in cement bricks regarding their thermomechanical properties in order to develop an eco-friendly building material. Polyethylene terephthalate (PET) and high-density polyethylene (HDPE) partially substituted cement with different ratios (0, 2.5, 5, 7.5, 10, 20%). The type that achieved better thermomechanical performance further replaced the other brick components; sand and coarse aggregates to determine the optimum replacement scenario and best design mix. Laboratory experiments have been carried out to measure the compressive strength, indirect tensile strength, bulk density, and thermal conductivity of the new composites. The measured results revealed better performance for the samples with HDPE than PET. A boost in the compressive strength and indirect tensile strength was noticed for the samples obtaining a limited amount (up to 7.5%) of HDPE. However, a reduction in the tested mechanical properties occurs with higher substitution levels. With respect to thermal conductivity and bulk density, they decreased with the increase of plastic waste. The best mechanical behavior and the highest thermal resistance were obtained by partial replacement of coarse aggregates with 7.5% and 20% HDPE respectively. The results represent a good contribution to energy conservation, waste management and sustainability.

Assessment of mechanical and durability properties of composite cement-based recycled aggregate concrete

The decade 2014–2024 is known as the sustainable decade, as a result of which there is a need to develop eco-friendly building materials and adopt sustainable construction practices. Utilizing larger proportions of industrial by-products reduces the carbon footprint on the environment caused by the cement manufacturing process. Also, the demand for natural aggregates is surging rapidly, hence recycled aggregates or recycled concrete coarse aggregates are being used as an alternative to natural aggregates. But there is a lack of studies based on the utilization of composite cement (fly ash and slag as blending materials) along with 100% recycled concrete aggregates. In the present study composite cement-based, recycled aggregate concrete is developed for varying water-cement ratios of 0.3 to 0.7 for 100% replacement of natural aggregates with recycled concrete coarse aggregates. These concretes were studied for mechanical properties and durability properties like water permeability, chloride ion permeability, corrosion resistance and resistance to carbonation. It is concluded from the current study that; the developed concrete consisting of 100% RCA and composite cement exhibits compressive strength between 25 MPa and 60 MPa for decreasing w/c from 0.7 to 0.3 respectively. Also, a well-designed mix with dense aggregate grading, ensures that the carbonation exhibited by this concrete is negligible and satisfies all the durability requirements. Hence it can be employed in the real-time construction of buildings.

Investigation on red mud and fly ash-based geopolymer: Quantification of reactive aluminosilicate and derivation of effective Si/Al molar ratio

The utilization of red mud (RM) as an aluminosilicate precursor (AP) for geopolymer production is attracting increasing research interest. This use of RM offers a desirable outlet for the increasing RM inventory and provides a sustainable solution for the immobilization of heavy metals and the valorization of waste as eco-friendly building materials. However, the effect of RM and its caustic residue on geopolymerization remains uncertain because of the extremely varied characteristics of RM. This study investigates the potential of using RM supplied from a local alumina refinery as an AP. First, RM was used to partially replace fly ash (FA) and the strength activity index (SAI) of the RM was evaluated. Second, to gain a deeper insight into the effect of caustic residue on geopolymerization, performances of traditional FA-based geopolymer and red-mud–fly-ash (RMFA)–based geopolymer under different NaOH concentrations were investigated and compared. Third, based on alkali leaching tests, the effective molar ratios considering the reactive content of RM and FA were developed, compared with conventional nominal molar ratio, and verified intensively using scanning electron microscopy–energy-dispersive spectroscopy (SEM-EDS).

Sustainability of pre-treated and nano-fly ash powder on the thermal stability and environmental impact of green mortars under ambient conditions

Safety during fire exposure conditions paid a lot of attention in today's modern construction activities which demands the exploration of thermally stable and eco-friendly building materials. During the elevated temperature conditions, the building with Portland cement construction experienced large rate of decomposition and heavy spalling. To achieve the thermal stability and sustainability in the building construction, an alternative zero cement geopolymer system was developed by using pre-treated and cost-effective nano-fly ash powder. The thermal stability of the developed nano-fly ash impregnated geopolymer mortar was assessed under various temperatures in terms of weight loss, visual observation and the post fire residual strength. Also, the results were validated by means of conducting Thermo Gravimetry Analysis, Fourier Infrared Spectroscopy and Scanning Electron microscopic analysis. From the results, it was observed that the geopolymer mortars with 1% nano-fly ash impregnation exhibited the highest compressive strength at all the temperature conditions. Also, the nano-fly ash added geopolymer mortars retained with 67% of its original strength even after the maximum temperature exposure of 900 °C. The use of pre-treated and nano-fly ash completely eliminates the need of superplasticizer and oven curing due to the improved reactivity. Also, the developed green mortar resulted in 46% reduced green house gas emission and 18.3% reduced cost of construction which paves the way to the development of cost-effective and sustainable geopolymer construction under fire explosive environments.

Experimental and analytical study on structural performance of reinforced lightweight geopolymer composites panels

Various lightweight panels such as autoclaved aerated concrete (AAC) panels have been widely used in the prefabricated construction. With the growing demand for eco-friendly building materials, geopolymer as cementitious material has been extensively studied. A novel ambient-cured lightweight geopolymer composite (LGC) with expanded polystyrene (EPS) was recently developed by the authors and demonstrated sound static and dynamic mechanical properties. In this study, a new lightweight reinforced panel made of LGC is proposed for prefabricated structures. Five full-scale panels, including one AAC panel and four LGC panels with different configurations, were prepared and tested under four-point bending to investigate the effects of panel thickness and reinforcement configuration on the structural performance. The test results showed that the LGC panels demonstrated better structural performance, with the characteristic ultimate bending capacity 57%-110% higher than that of the corresponding AAC panel. An analytical study was also conducted, and empirical formulae were proposed to predict the ultimate bending capacity of LGC panels.

Box-Behnken design based optimization and characterization of new eco-friendly building materials based on slag activated by diatomaceous earth

Blast-furnace slag-based geopolymers activated by gels siliceous rock (diatomaceous earth) were synthesized at room temperature. Using a Box Behnken plan and surface response design approach (RSM), the diatomaceous earth content, NaOH molarity, and liquid/solid ratio were used as factors to optimize and evaluate compressive strength, bulk density, porosity, and water absorption. The analysis of variance “ANOVA” revealed that the modelling factor ensembles were significant. Therefore, the high values of coefficient of determination adjusted “R2Adj” (R2Adj-Cs = 95.42%, R2Adj-BD = 92.36%, R2Adj-P = 98.76%, R2Adj-WA = 98.24%), confirm the established models' adequacy. The RSM demonstrated that at a liquid/solid ratio of 0.59, a NaOH molarity of 7.5 mol/l, and a diatomaceous earth percentage of 9.5%, a geopolymer with high physico-mechanical properties could be produced (compressive strength = 42 MPa, bulk density = 1.67 g/cm3, porosity = 18.98%, and water absorption = 11.27%). The optimal geopolymer's microstructural analysis revealed that geopolymer synthesis under optimal conditions supported the formation of a substantial percentage of geopolymerization products, and hence the production of high-performance alkali-activated materials.

Eco-friendly construction materials and health benefits in the design of an all-inclusive health resorts, Nigeria

Health resort designs are health sanctuaries and a conducive treatment, healing, and wellness environment. In providing a health and wellness-beneficial environment, the material selection choices by health resort designers should conform to certain minimum specifications and standards. On this premise and SDG-based selection criteria, the study aims to investigate eco-friendly construction materials and their health benefits in an all-inclusive health resort design proposed for Port Harcourt, Nigeria. This study addressed three key objectives—Ascertaining the physical architectural features of health resorts, assessing the eco-friendly building material contribution to SDG attainment, and identifying the health benefits of eco-friendly building materials in the health resort. The researchers engaged the qualitative research method for the study, using a case study technique as a qualitative research design/strategy. The authors used three health resorts across three countries in the global south; China, India, and Brazil. The data collection instruments include; an in-depth interview guide In-depth Interviews (IDI), a direct observation guide, a checklist of green construction materials for health facilities and a qualitative photo-production study based on the essential features of a health resort checklist. The authors use content and narrative analyses to analyze data. Findings show that eco-friendly materials may be best suited for both exterior and interior works of health resort facilities. Wood, stone and concrete are the most preferred materials as they occur across all three case studies. The results align with current global trends towards eco-beneficial facilities. Adopting natural materials such as wood and stone for the Port Harcourt health resort would be expedient, given the health benefits inherent in using such eco-friendly materials and their alignment with the Sustainable Development Goals (SGD 11 and 13).

Hydronic flow path analysis on the thermal comfort performance of radiant cooling system

Construction and operation in the building sector account for more than 1/5th of global energy consumption. Moving on to an energy-efficient cooling technology and eco-friendly building material can lead to energy savings and a reduction in associated CO2 emissions. In the present study, an energy-efficient thermally activated building system (TABS) is integrated with eco-friendly building material, namely, glass fibre reinforced gypsum (GFRG). The proposed hybrid system is termed as thermally activated glass fibre reinforced gypsum (TAGFRG) system. This system is not only energy-efficient and eco-friendly but also provides better thermal comfort. An experimental room is constructed with the TAGFRG roof within the Indian Institute of Technology Madras campus, Chennai, i.e., in a tropical warm and humid climate zone. The TAGFRG roof has reinforcement in every third cavity with cooling pipes, while in the other two cavities, cooling pipes are embedded with air gap and partial reinforcement. The TAGFRG roof has four parallel loops of cooling pipelines, and each loop consists of one reinforcement zone (RZ) and two air gap zones (AZ1 and AZ2) in series. According to the water flow path in a single loop, various combinations of the flow path, i.e., RZ → AZ1 → AZ2, AZ1 → RZ → AZ2 and AZ1 → AZ2 → RZ, have been analyzed. According to the adaptive thermal comfort model, the water flow path has a negligible effect on thermal comfort. The average operative temperature for all the cases investigated varies between 28.1 and 29.2 °C. The operative temperature is always within the 90% band of thermal comfort, as per the adaptive comfort model.

Editorial: Sustainable and eco-friendly building materials

EDITORIAL article Front. Built Environ., 20 February 2023Sec. Construction Materials Volume 9 - 2023 | https://doi.org/10.3389/fbuil.2023.1160556

Study of Recycled Spent Coffee Grounds as Aggregates in Cementitious Materials

Most spent coffee grounds (SCGs), a byproduct of brewing coffee, are buried in landfill sites, and their decomposition produces significant greenhouse gases. As the recent warming of the Earth’s climate has made it imperative that industries reduce greenhouse gas emissions, the present study investigates the viability of recycling SCGs for use as a partial replacement of aggregates in concrete materials. Cement mortar samples with a fixed cement-to-water ratio and varying amounts of SCGs were fabricated and tested. Mechanical strength tests revealed that an appropriate amount of SCGs can improve compressive strength. However, since strength deterioration was also observed in samples with too much or too little SCG content, finding the optimal amount is necessary for implementation. The samples’ thermal conductivity decreased as the amount of SCGs increased, capturing the effective insulating substance of air within the SCGs’ porous structure. The increased insulating capacity of concrete materials resulting from the addition of SCGs could be beneficial in terms of a building’s lifecycle cost and carbon emissions. Thus, the SCGs once disposed of in landfills to emit greenhouse gases can be transformed into an appealing and eco-friendly building material if the proper concrete mix ratio is used.

A simulation-aided approach in examining the viability of passive daylighting techniques on inclined windows

As the construction industry moves towards sustainability, buildings are frequently constructed using eco-friendly building materials and techniques. It is important to evaluate various passive daylighting techniques in order to obtain natural light into the building in the most eco-friendly manner feasible. As part of our investigation, the office in study has inclined windows, limiting the amount of solar radiation entering and shielding the building occupants from direct sunlight. Thus, it is critical to identify an appropriate passive daylight design that reduces renovation work without disrupting mechanical, electrical, and plumbing (MEP) services. By using photorealistic simulation and Radiance daylight simulation to compare various types of light shelves across different levels, it offers a practical solution with low installation costs to address inadequate daylighting with inclined windows. This will assess the effectiveness of daylight penetrations and enhance visual comfort in a high-rise structure with inclined windows. Our research findings demonstrate that, even when installed on inclined windows with daylight infiltrations, the combination of tilted light shelves performs better in reflecting daylight into the internal space, with an estimated 34% better performance and a more than 25% reduction in energy usage. Aside from daylight simulation, the chiller load simulation results show that the combination of tilted light shelves has no effect on the chiller loads, indicating that no heating is involved. Our work here has the potential to enhance sustainability without requiring extensive retrofitting or changes to the original interior design, resulting in lower installation and renovation costs while improving occupant health and welfare at the same time.

Review on the Suitability of Bamboo as a Building Material in Nigeria

Bamboo is adjudged to be a very good sustainable, versatile and eco-friendly building material. It grows naturally in most of the world’s forests especially in tropics and sub-tropical regions. Bamboo is the fastest growing grass in the world and matures within three to five years. It consumes carbon (iv) oxide (the major greenhouse gas) in the environment through photosynthesis and releases oxygen to the environment thereby drastically reducing the greenhouse gases and making the environment safe. Throughout the entire globe, there is increase in human population. As the number of humans in the world increases, there is proportional increase in the need for shelter and other civil infrastructures. This increase in need for shelter and other civil infrastructures has resulted in over-consumption of traditional building materials and has created serious burden on the depleting world’s natural resources. Continuous use of the traditional building materials like steel, timber, cement, has also led to increase in the burning of fossil fuels which releases greenhouse gases to the environment during their production. Nevertheless, traditional building materials are very expensive and their continuous use leads to increase in the overall cost of buildings and other civil infrastructures. The use of bamboo as a material for construction of buildings and other civil infrastructures presents a very huge relief to the aforementioned problems encountered in the construction industry. This paper x-rays the viability of bamboo as construction material in Nigeria. Increase in the use of bamboo in the construction industry will lead to reduction in the overall construction cost, growing bamboo in commercial quantity and reduction of greenhouse gases in the environment