Sustainable Building Materials Research Articles

Predictive modelling for the acid resistance of cement-based composites modified with eggshell and glass waste for sustainable and resilient building materials

The increasing demand for cement-based composites (CBCs) due to the advancement of infrastructure causes the exhaustion of natural materials and environmental pollution. Also, dumping industrial and agro-derived waste materials in landfills has negative impacts. Therefore, producing waste-derived CBCs by partially replacing cement and sand will be a favourable approach. Since CBCs' performance degrades when exposed to hazardous substances, their efficacy in a hostile environment is the key concern. This work utilised new computing methods to estimate the reduction in compressive strength (CS) of eggshell and glass powder-modified cement mortar (EG-CM) exposed to acidic conditions. Machine learning-based methods, including gene expression programming (GEP), decision tree (DT), multilayer perceptron neural network (MLPNN), and support vector machine (SVM), were employed. In addition, to examine the effectiveness of eggshell and glass powder for acid resistance, the SHapley Additive exPlanations (SHAP) approach was used. The built models exhibited good prediction performance for evaluating the loss in CS of EG-CM after the acid attack. SVM was noted to be the most accurate predictor with the highest R2 and least errors. SVM, DT, MLPNN, and GEP yielded results with R2 values of 0.88, 0.87, 0.85, and 0.85, respectively. The mean absolute percentage error for MLPNN was 17.9%, GEP was 15.5%, DT was 15.0%, and SVM was 10.6%. These error evaluations further confirmed the SVM's greater accuracy compared to other models. The SHAP study showed that glass powder was the most important element for EG-CM's resistance to CS loss after an acid attack, followed by 90-day CS, eggshell powder, cement, sand, silica fume water, and superplasticiser.

Acoustic Property of NBRRI Interlocking Compressed Stabilized Earth Blocks (ICSEB): A Sustainable Alternative for Building Materials

This study uses a tested laterite soil composition to investigate the acoustic properties of interlocking compressive stabilized earth blocks (ICSEBs) produced by the Nigerian Building and Road Research Institute (NBRRI). The laterite samples comprised 40.75% fines (silt-clay), 48.65% fine/medium/coarse, and 10.6% fine gravel. The ICSEBs produced from this composition were evaluated for their sound absorption coefficient values at octave bands of 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz. The results demonstrate that the ICSEBs exhibit favorable acoustic insulation properties, with sound absorption coefficients ranging from 0.71 to 0.99 at the tested frequencies. Comparative analysis with commonly used materials, such as fiber-glass insulation batts and acoustic plasterboard, highlights the competitive performance of the ICSEBs. This study emphasizes the need for further research to explore the influence of composition, thickness, and installation methods on the acoustic performance of ICSEBs, ensuring their suitability for specific applications. Meanwhile, the findings indicate that ICSEBs made from the laterite soil composition can be a cost-effective and durable solution for acoustic insulation in building construction. Therefore, this study provides valuable insight into the acoustic properties of ICSEB, which could be helpful for architects, engineers, and builders who seek to incorporate sustainable and cost-effective building materials in their projects.

A REVIEW OF ISSUES AND OPPORTUNITIES OF ARCHI-PRENEURSHIP PRACTICE IN NIGERIA

This article appraises issues and opportunities of architectural entrepreneurship (archi-preneurship) practice in Nigeria. It recognises the relevance of entrepreneurial orientation in the architectural syllabus as a consequence of the emerging issues facing the career path and derived from students' long-term educational needs to prepare them for a successful job in a competitive global economy. Hence, industrialisation, job creation, and poverty alleviation processes are accentuated by entrepreneurship. To find out these issues and opportunities of archi-preneurship, a systematic review approach was adopted to source current relevant data from Academia, Elsevier, ScienceDirect, Google Scholar, MDPI, and ResearchGate databases for this study, which focused on programmes relating to the architecture profession that can help entrepreneurs grow and make conclusions. The concepts of entrepreneurship, architecture, and technology were explored. Five specialisation areas that would potentially facilitate entrepreneurial prospects in Nigeria were identified, and the challenges they present to architects. These components include architecture consultation; research and application of building information modeling (BIM) technologies; property development and construction, retrofitting and energy efficiency; sustainable building material science; and urban design. Some available skills architecture graduates could engage in include landscaping, interior design, graphics and animation, project management, architecture blogging, forensic architecture, and building pathology among others. The study outlines different aspects that architects should consider to de-emphasise the hunt for non-existent office employment and embrace self-occupation. Also, more entrepreneurial training skills and development programmes should be established, as well as a reassessment of the present syllabi to instill business knowledge at all stages of architecture education.

Seismic Performance and LCA Comparison between Concrete and Timber–Concrete Hybrid Buildings

The growing demand for energy-efficient and environmentally sustainable building materials has led to an increasing interest in hybrid timber-concrete construction. These structures combine the advantages of the two materials, potentially reducing the carbon footprint, shortening construction timelines, and improving seismic and building physics performance. Herein the structural and environmental performance of ten-story timber-concrete hybrid and a pure concrete building, designed for the Guizhou Province, China, were compared. The structural analysis revealed a significant reduction in the self-weight and base shear of the hybrid structure. The life-cycle analysis demonstrated that the hybrid building outperformed the concrete building in six categories, including global warming potential, acidification potential, human health particulate, eutrophication potential, ozone depletion potential, and photochemical ozone formation potential. Notably, the hybrid building exhibited nearly 65% lower emissions in terms of global warming potential. Moreover, the inclusion of wood components offered the added benefit of carbon storage throughout their lifespan. These findings provide compelling support for the development and implementation of high-rise timber-based hybrid buildings in China. The advantages observed in both structural and environmental aspects encourage the adoption of this innovative construction approach, contributing to sustainable and eco-friendly building practices.

Natural and manmade fibers as sustainable building materials

This review paper aims to assess of workability, mechanical and durability parameters of mortar and concrete developed by several natural and manmade fibers. Natural and manmade fibers were used by several researchers for enhancing the inherent properties of mortar and concrete. Various researches were carried out and the outcome of their studies are concisely depicted in this paper. The objective of this study is to accumulate the existing data on natural and man-made fibers assessed in the last few years, and consequently, it can be utilized as a reference paper for further research on a specific fiber. Typically natural and manmade fibers are utilized to enhance the mechanical strength characteristics of the mortar and concrete. Though all parameters cannot be value-added due to differences in fiber's character. Hence it is suggested that suitable fiber should be used based on the place of application. Similarly, a standard guideline should be maintained for the recognition of natural and man-made fibers due to variations in the properties of a particular fiber in diverse areas. Indeed, natural and manmade fibers can be utilized through a wide zone, yet the need for research for fiber characterization and its impact as a sustainable alternative building material on the construction industry is tranquil essential.

Assessing the thermal performance of upcycled shipping container as a sustainable building material in a Warm humid climate

The current trends in the construction sector are responsible for majority of the CO2 emissions in India. The sustainable methods to reduce the CO2 emissions should include not just recycling but also upcycling the materials, for instance – shipping containers. Despite the industry’s best efforts to minimize waste generation, millions of shipping containers end up as scrap materials, every year. This phenomenon can be changed effectively by reusing the scrap materials as alternate building materials. The trend of reusing the shipping containers as building materials is at its peak in Western countries, while in India, it is still in a nascent stage. The aim of the current research paper is to evaluate and assess the thermal performance of upcycled shipping containers as a building material in warm humid climatic condition. This research includes a review of literature about the strengths and weaknesses of the shipping containers as a building material; it also compares and evaluates the thermal performance of uninsulated container buildings with base case conventional building and the insulated container building through Opaque simulation method. The results were obtained by comparing and assessing the thermal performance and cost of various insulating materials for a container building. The study outcomes greatly help the architects to reuse the shipping containers as a sustainable alternative building material in warm humid regions.

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.

“Solid industrial waste generation and its valorization in developing sustainable building materials- A state of the art review”

Eco-efficient product development is going to be essential for the construction industry from the sustainability point of view as one way it lower down the environmental burden and another way it emphasizes on solid waste management to protect the mother nature. This study is intended to carry out the literature review to identify the various waste which has been used in mortar developments in 21st century (from year 2000 to year 2022). Waste has been selected from various industry i.e. Glass Waste, Marble Waste, Sandstone Waste, Limestone, Plastic Waste, Wood Waste, Construction and Demolition Waste, Ceramic Waste, Sludge from treatment Plants, Shell Waste, Rubber Waste, Bio Waste, Ashes etc. the literature review shows that these wastes can be utilized in the mortar development with a certain quantity as a substitute to fine aggregate or Natural Sand. The amount of substitution depends on the various parameter of the waste i.e. Physical, Chemical, morphological characteristics along with the ease of production, Transportation, Durability etc. in recent time most predominantly used waste in mortar development is found to be Glass Waste, Manufacturing Industry Waste, Construction and Demolition Waste and ceramic Waste. The literature collected for two decades from year 2000 to year 2022 has suggested optimum fraction of sand substitutions as 20% to 30% subjected to fresh and hardened properties, Durability, Morphological consideration, Microstructural Assessment. The ideal and most commonly used fraction of waste for mortar development can also be determined.

Chemical Treatments for Coffee Husks: Application in Mortar for Coating and Laying Blocks

(1) The use of agro-industrial wastes, such as coffee husks, in cementitious materials is a viable way to achieve the sustainable development of new construction materials. Traditionally, these wastes are applied after calcination, spending energy and financial resources. Furthermore, the calcination of these wastes contributes to a more sustainable environment. This is interesting because calcination treatments are usually more expensive than those using chemical treatments. Thus, the objective of this research is to evaluate the possibility of using coffee husks with the use of chemical treatments with sodium and potassium hydroxide in mortars for coating and laying blocks. (2) The methodology of this article consists of producing test specimens of mortar for coating and laying blocks in the composition 1:1:6:1.55 (cement: hydrated lime: sand: water), using coffee husks that will be incorporated in quantities of 2.5% in relation to the mass of the cement in its natural state and after treatment with sodium and potassium hydroxide. Compositions containing calcined coffee husks are evaluated for comparison purposes. The evaluated parameters were the mass density in the hardened state, water absorption by immersion and compressive strength. To complement these analyses, XRD, SEM and calorimetry tests were executed to compare the proposed treatments. (3) The results indicate that the use of treatments with NaOH and KOH allows for the use of coffee husks in mortars, since the parameters obtained were compatible with this type of application. The use of natural coffee husks is not possible due to their low compressive strength and high water absorption, caused by porosity. The use of alkaline treatments, especially with KOH, does not affect the hydration of the cement, allowing for the obtention of values statistically equivalent to the reference composition. The results with calcined coffee husks are even more promising due to the high content of amorphous potassium, which promotes the conversion of ettringite into hydrous calcium aluminate monosulfate. (4) It is concluded that, for the application of coffee husks in mortars for coating and laying blocks, the chemical treatment with KOH meets the necessary parameters—for example, a compressive strength greater than 2 MPa, making sustainable building materials and promoting the use of agro-industrial waste in building materials.

A Personalized Individual Semantic Extraction Model Based on Criterion for Adaptive Consensus Reaching Process Under Improved Basic Uncertain Linguistic Environment

Personalized individual semantics (PIS) is an important factor reflecting the personal habits of decision makers (DMs) and has been widely studied by scholars. Using criteria as a non-negligible information source in multi-criteria group decision making (MCGDM), how to extract PIS from it is a research gap to be solved. In addition, existing measurements of consensus are insufficiently sensitive to differences between individuals, while the current direction rules use a matrix as the unit of measurement, which is not detailed and precise enough. Therefore, this paper first constructs a PIS extraction model according to the principle that similar criteria have similar descriptions and mutually exclusive criteria have dissimilar descriptions. Secondly, the preference information of PIS is mingled with uncertainty and reliability of improved basic uncertain linguistic information (IBULI) as the data of the consensus reaching algorithm. The proposed consensus algorithm not only fully considers the dispersion of DMs in the consensus measurement stage, but also improves the objectivity of the consensus process through an adaptive feedback stage. Finally, the validity of the proposed model is verified by an example and comparative analysis of the selection of sustainable building materials.

A Sustainable Building Material Developed from Low-Temperature Sintering of Mining Waste with an Alkali-Silicate Solution

The development of glass-ceramic foam has received significant attention in building and construction, given its potential for sustainability. This study investigated the low-temperature route of fabricating glass-ceramic foams from mining waste. The feasibility of one-step or chemical-aided sintering of glass-ceramic foams using granite powder, a naturally sourced mining waste, rather than using already heat-treated wastes such as glass and fly ash has been explored in this study. Glass-ceramic foam samples were synthesized from a homogenous blend of constant percentage by weight of granite-clay mix with varying amounts of alkali-silicate solution. The influence of the alkali-silicate solution on the physicomechanical and microstructural properties of the synthesized samples sintered at 850°C was investigated. The results showed water absorption of 9.5-33.3%, apparent porosity of 18.2-56.7%, bulk density of 1.7-1.91 g/cm3, and compressive strength of 20.7-26.3MPa. The glass-ceramic foam developed in this research can be suitably used for the thermal insulation of buildings.

The influence of water-cement ratios and alumino-silicate based accelerator on the properties of fiber-reinforced cement composites

Due to more strict environmental protection and greenhouse gas reduction, it is very important for all industries to appropriately manage their energy consumption. Fiber- reinforced cement composites are the popular building materials which consume enormous energy to intensify its chemical reaction during the autoclave steam curing process. Utilization of chemical admixture to replace the conventional energy-driven autoclave steam curing process will support the fiber- reinforced cement composites industry to develop sustainable building materials. In this research, typical and mechanical properties of the air-cured fiber- reinforced cement composites incorporated with alumino-silicate based accelerator were investigated. The results show an excellent positive correlation between the water-cement ratio of the mix design and the mechanical strength which is the optimum water-cement ratio for this FRCC are 0.53. Moreover, the properties of fiber- reinforced cement composites cured by either the autoclave steam curing process or air-curing process are comparable.

Recycling cenospheres to construct chitosan bonded-ammonium polyphosphate/dipentaerythritol hybrid geopolymer coatings for flame-retarding plywood

Cenosphere is an industrial solid waste produced by coal-fired power plants. Its large discharge has resulted in significant environmental problems, and how to solve this problem has become a top priority. In this research, chitosan (CS) bonded-ammonium polyphosphate (APP)/dipentaerythritol (DPER) are employed to construct cenospheres-based geopolymer coatings using the sol-gel method for flame-retarding plywood. The experimental results indicate that an appropriate pretreatment of APP with CS (0.40 wt%) facilitates the formation of geopolymer coatings, resulting in non-combustible resilient residues during combustion, its effectively block heat and fire sources, significantly decreasing the peak heat release rate from 108.89 to 90.61 kW m−2 and reducing about 80% of smoke production. Meanwhile, the three-level chemical reaction model is identified to govern the hybrid coatings’ pyrolysis. The calculations clarify that an appropriate CS increases its Eα from 266.03 to 345.16 kJ mol−1 at 727–1000 °C, corresponding to enhanced thermal stability. Furthermore, the yielded residues exhibit a formaldehyde adsorption rate of 71.6%, attributed to the formation of interpenetrating networks. Incorporating CS-pretreated APP in cenospheres-based coatings for designing Si–C–P hybrid coatings provides an effective method for recycling cenospheres and promotes the development of sustainable building materials.

Microstructural Analysis and Compressive Strength of Fly Ash and Petroleum Sludge Ash Geopolymer Mortar under High Temperatures

The development of sustainable building materials and construction to decrease environmental pollution in both production and operational stages of the materials’ life cycle is appealing to great interest in the construction industries worldwide. This study evaluated the negative effect of temperature up to 1000 °C on the compressive strength and microstructure of fly ash and petroleum sludge ash (PSA) geopolymer mortar. A sodium silicate and sodium hydroxide mixture is used as an activator. The synthesized mortar was investigated using X-ray Diffraction (XRD), Fourier Transformation Infrared Spectroscopy (FTIR), Mercury Intrusion Porosimetry (MIP), and Field Emission Scanning Electron Microscopy (FESEM). As the temperature increased, the compressive strength of the geopolymer mortar decreased. The strength degradation is due to the damage to microstructure because of the temperature-induced dehydroxylation, dehydration thermal incompatibility between geopolymer aggregate and paste of geopolymer mortar at high temperatures. With an increase in temperature, the cumulative pore volume increased. The FESEM image showed the decomposition of the geopolymer matrix started at a temperature of 600 °C. Incorporating PSA in geopolymer mortar could result in an eco-friendly and sustainable environment that may reduce the problems associated with sludge disposal.

APPLICATION OF BIO-BRICKS & ITS BENEFITS

AbstractThe practice-led research focuses on how agro-waste can be used to build a structure, gather relevant knowledge, and identify its various challenges. Based on the compressive strength of Bio-Bricks, it was decided to use a frame structure, and instead of using Bio-Bricks as a modular unit, the material used was cast in situ with the help of a specially designed mould. The roofing of the structure was also built using Bio-Bricks material over an MS frame. The prototype was plastered with cement mortar and finished with two coats of distemper paint. After the completion of the prototype structure, comprehensive documentation was done to analyse the data generated from the process to identify the desired improvements. A secondary study of sustainable building materials was done to understand the comparative strength and weaknesses of Bio-Bricks as construction materials. Based on the work done at different stages of construction, detailed lists of findings and inferences were drawn to improve the overall manufacturing process. The research project findings will help guide the future development of Bio-Bricks as a commercial building material.

Production and Incorporation of Calcium-Hydrolyzed Nanoparticles in Alkali-Activated Mine Tailings.

This work presented the production and incorporation of calcium-hydrolyzed nano-solutions at three concentrations (1, 2, and 3 wt.%) in alkali-activated gold mine tailings (MTs) from Arequipa, Perú. As the primary activator solution, a sodium hydroxide (NaOH) solution at 10 M was used. Calcium-hydrolyzed nanoparticles with a particle size of 10 nm were localized inside self-assembled molecular spherical systems (micelles) with diameters of less than 80 nm that were well-dispersed in aqueous solutions and acted as secondary activator, and also as additional calcium resource for alkali-activated materials (AAMs) based on low-calcium gold MTs. High-resolution transmission electron microscopy/energy-dispersive X-ray spectroscopy (HR-TEM/EDS) analyses were carried out to characterize the morphology, size, and structure of the calcium-hydrolyzed nanoparticles. Fourier transform infrared (FTIR) analyses were then used to understand the chemical bonding interactions in the calcium-hydrolyzed nanoparticles and in the AAMs. Scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS) and quantitative X-ray diffraction (QXRD) were performed to study the structural, chemical, and phase compositions of the AAMs; uniaxial compressive tests evaluated the compressive strength of the reaction AAMs; and nitrogen adsorption-desorption analyses measured porosity changes in the AAMs at the nanostructure level. The results indicated that the main cementing product generated was amorphous binder gel with low quantities of nanostructured C-S-H and C-A-S-H phases. The surplus production of this amorphous binder gel produced denser AAMs at the micro-level and nano-level (macroporous systems). In addition, each increase in the concentration of calcium-hydrolyzed nano-solution had a direct/proportional effect on the mechanical properties of the AAM samples. AAM with 3 wt.% calcium-hydrolyzed nano-solution had the highest compressive strength, with a value of 15.16 MPa, which represented an increase of 62% compared with the original system without nanoparticles that were aged under the same conditions at 70 °C for seven days. These results provided useful information about the positive effect of calcium-hydrolyzed nanoparticles on gold MTs and their conversion into sustainable building materials through alkali activation.

Mortar and concrete with lime-rich calcined clay pozzolana: A sustainable approach to enhancing performances and reducing carbon footprint

Low environmental impact sustainable building materials have become a crucial requirement and challenges to the contemporary construction industry. This study is an extensive effort for the development of a green cementitious composite to limit extensive extraction and consumption of nonrenewable mineral resources and CO2 emission generation by the reduction of clinker cement production. In this route, 10%, 25%, 35%, and 50% of CaO-based calcined clay were adopted as a partial replacement for ordinary Portland cement (OPC) in mortar mix. The raw clay was extracted from Nizwa city (NZS) and ground into particles with size less than 75 µm. As per its chemical composition, the clay was classified as cementitious and pozzolanic material as per ASTM C618 standard specifications. The mill was then calcined at different temperatures of 950 °C, 850 °C, and 750 °C. The blend mortar mixes were assessed in terms of their mechanical, microstructural, durability, and thermal performances using various experimental tests. The results indicated that replacement levels of lime-rich calcined clay varying from 10% to 35% of OPC could generally offer similar to better strengths, durability, and thermal performances to a plain mortar. The mortar flow was reduced when incorporating calcined clay, while density was unaffected. Meanwhile, CaO-based calcined clay generally exhibited better performance with regard to permeable voids, combined sulphate + chloride, sulfuric acid attacks, and chloride ions permeability. The outcome of the present work sheds light on the massive potential of calcined clay pozzolana to develop sustainable, affordable, and locally produced blend cement for a variety of infrastructure applications, including energy-efficient and sustainable development, to reduce the carbon footprint.

In-situ polymerized zinc ions chelated Si-C-N cenospheres-based geopolymeric coating constructed by incorporating β-cyclodextrin and dopamine for flame-retarding plywood

Preparing halogen-free and efficient bio-flame retardants by recycling industrial solid waste is crucial for creating an environmentally friendly human settlement. Herein, β-cyclodextrin(β-CD) and dopamine(DA) are employed to chelate zinc ions (β-CD@Zn@DA) involved in cenospheres-based geopolymeric coating for further flame-retarding plywood. The results show that an appropriate dosage of β-CD (1.2 g, 1.00 wt%) improves the flame retardancy of the geopolymeric coating, and the peak heat release rate decreases from 107.17 kW·m−2 to 66.04 kW·m−2, the flame retardancy index increases from 1.00 to 1.41. Meanwhile, due to hydrogen bonding cross-linking and chelation of zinc ions, the coating is transformed into a dense and non-flammable ceramic-like blocking layer during firing to prevent heat or mass transfer. Furthermore, the pyrolysis kinetics identify that the Z.-L.-T. three-dimensional diffusion–reaction model governs the coatings’ pyrolysis, and an appropriate β-CD makes the pyrolysis Eα climb from 186.08 to 237.41 kJ·mol−1 at 980 ∼ 740 °C, corresponding to the resilient residues for blocking heat and fire. Therefore, in-situ polymerized zinc ions, chelated β-CD, and DA for facilely designing Si-C-N hybrid flame-retarding coating is explored, promoting the recycling of industrial solid waste and the development of more sustainable building materials.

Influence of Ventilation Openings on the Energy Efficiency of Metal Frame Modular Constructions in Brazil Using BIM

Construction projects demand a higher amount of energy predominantly for heating, ventilation, and illumination purposes. Modular construction has come into the limelight in recent years as a construction method that uses sustainable building materials and optimizes energy efficiency. Ventilation openings in buildings are designed to facilitate air circulation by naturally driven ventilation and could aid in reducing energy consumption in construction projects. However, a knowledge gap makes it difficult to propose the best dimensions of ventilation openings in buildings. Hence, the aim of this work is to empower the decision-making process in terms of proposing the best ventilation opening dimensions toward sustainable energy use and management in buildings. A novel framework is presented herein to evaluate the impact and propose the best dimensions of ventilation openings for metal frame modular construction in Brazil, using building information modeling. The ventilation openings were constructed and their dimensions evaluated in eight Brazilian cities, based on the bioclimatic zone (BioZ) classification indicated in ABNT NBR 15220: Curitiba (1st BioZ); Rio Negro (2nd BioZ); São Paulo (3rd BioZ); Brasília (4th BioZ); Campos (5th BioZ); Paranaíbe (6th BioZ); Goiás (7th BioZ); and Rio de Janeiro (8th BioZ). The study results show that the energy consumption of the same building model would vary based on the dimensions of ventilation openings for each BioZ in Brazil. For instance, modeling the same modular construction unit in the city of Rio Negro could consume around 50% of the energy compared to the same unit constructed in the city of Rio de Janeiro, using the small opening sizes based on the smallest dimensions of the ventilation openings. Similarly, modeling the construction unit in Curitiba, São Paulo, Brasília, Campos, Paranaíba, and Goiás could reduce energy consumption by around 40%, 34%, 36%, 18%, 20%, and 16%, respectively, compared to constructing the same building in the city of Rio de Janeiro, using the small opening sizes based on the smallest dimensions of the ventilation openings. This work could help practitioners and professionals in modular construction projects to design the best dimensions of the ventilation openings based on each BioZ towards increasing energy efficiency and sustainability.

Rosaceae Nut-Shells as Sustainable Aggregate for Potential Use in Non-Structural Lightweight Concrete

Apricot (AS), peach (PS), and plum shells (PlS) were examined as sustainable aggregates for non-structural lightweight concrete. The extraction of natural resources has a significant environmental impact and is not in line with the Sustainable Development Goals (SDGs) of Agenda 2030. Recycling agri-food waste, such as fruit shells, fully respects circular economy principles and SDGs. The chemical and physical properties of the shells were investigated using scanning electron microscopy (SEM) for microstructure analysis and TG-MS-EGA for thermal stress behavior. Two binding mixtures were used to prepare the concrete samples, one containing lime only (mixture “a”) and one containing both lime and cement (mixture “b”). Lime is a more sustainable building material but it compromises mechanical strength and durability. The performance of lightweight concrete was determined based on the type of aggregate used. PS had a high-water absorption capacity due to numerous micropores, resulting in lower density (1000–1200 kg/m3), compressive strength (1–4 MPa), and thermal conductivity (0.15–0.20 W/mK) of PS concrete. AS concrete showed the opposite trend (1120–1260 kg/m3; 2.8–7.0 MPa; 0.2–0.4 W/mK) due to AS microporosity-free and denser structure. PlS has intermediate characteristics in terms of porosity, density, and water absorption, resulting in concrete with intermediate characteristics (1050–1240 kg/m3; 1.9–5.2 MPa; 0.15–0.3 W/mK).