Building Construction Materials Research Articles

Article title: Assessment of natural radioactivity (40K, 238U and 232Th) and radiological risk in building construction materials: the case of Benin hill granites

Continuous exposure to ionizing radiation can have harmful effects on human health. In this respect, a study was carried out in the Communes of Dassa-zoume and Glazoue to determine the levels of 40K, 238U and 232Th in granites and sand. The specific activities obtained made it possible to assess the possible radiological risks associated with the resident population. During sampling work in November 2022, twelve granite samples were taken from twelve quarries. In addition, a sand sample was collected in Cotonou for comparison. All samples were then sent to the INSTN-Madagascar laboratory for gamma-ray spectrometry analysis using a NaI(TI) detector. The results show that the average specific activities of 40K, 238U and 232Th in the granites are (1329 ± 128) Bq.kg-1, (44 ± 11) Bq.kg-1 and (129 ± 44) Bq.kg-1 respectively. Those in sand are (144 ± 8) Bq.kg-1, (30 ± 2) Bq.kg-1 and (56 ± 7) Bq.kg-1 respectively. The average equivalent radium activity is (330 ± 74) Bq.kg-1 versus (122 ± 10) Bq.kg-1 for sand. The mean gamma index for granite was (1.2 ± 0.3), compared with (0.43 ± 0.03) for sand. The average absorbed dose rate in air is (153.4 ± 9.4) nGy.h-1 versus (53.7 ± 5.1) nGy.h-1 for sand. For adults, for 80% building occupancy factor, the mean annual indoors and outdoors effective dose (E) inside a building are (0.75 ± 0.05) mSv.y-1 and (0.19 ± 0.01) mSv.y-1 versus (0.26 ± 0.05) mSv.y-1 and (0.07 ± 0.01) mSv.y-1 for sand. For 60% factor, the means are (0.56 ± 0.03) mSv.y-1 and (0.38 ± 0.02) mSv.y-1 versus (0.20 ± 0.01) and (0.13 ± 0.01) mSv.y-1 for sand. For the children, for a building occupancy factor of 80%, the average E are (0.86 ± 0.05) mSv.y-1 and (0.21 ± 0.01) mSv.y-1 versus (0.30 ± 0.01) mSv.y-1 and (0.08 ± 0.01) mSv.y-1 for sand respectively for indoors and outdoors. For infants, the E are (1.00 ± 0.06) mSv.y-1 and (0.25 ± 0.01) mSv.y-1 versus (0.35 ± 0.01) mSv.y-1 and (0.09 ± 0.01) mSv.y-1 for sand respectively for indoors and outdoors. For children, for a building occupancy factor of 60%, the average E are (0.64 ± 0.03) mSv.y-1 and (0.43 ± 0.02) mSv.y-1 versus (0.23 ± 0.01) mSv.y-1 and (0.15 ± 0.01) mSv.y-1 for sand respectively indoors and outdoors. For infants, for a building occupancy factor of 60%, the E are (0.75 ± 0.05) mSv.y-1 and (0.50 ± 0.02) mSv.y-1 versus (0.26 ± 0.01) mSv.y-1 and (0.18 ± 0.01) mSv.y-1 for sand respectively indoors and outdoors. For adults, the excess lifetime cancer risk at age 66 for a total annual effective dose induced by granite is (3.1 ± 0.01).10-3 versus (1.1 ± 0.01).10-3 for sand. For the children and infants, the average ELCR is (3.5 ± 0.01)E-3 and (4.1 ± 0.01)E-3 versus (1.2 ± 0.01)E-3 and (1.4 ± 0.01)E-3 for sand respectively. Statistical analysis of the data was performed with Python 3.11 and R 4.3.2 on the Spyder and studio interface. The p-value is < 0.001 compared with the UNSCEAR reference value for absorbed dose rate in air, effective dose and excess risk, which are 84 nGy.h-1, 0.48 mSv.y-1 and 0.29.10-3. This shows that the granites in the quarries studied present a radiological risk when used as building materials and need specific radiation protection measures for his users.

Strategies for Minimizing Material Waste with the Application of Lean Construction in Building Construction Projects

Waste of construction materials is one of the problems often experienced by several construction service actors in Bali, especially in Gianyar, the utilization of materials is not efficient so that the project experiences cost overruns. The purpose of this study is to identify the dominant indicators causing building construction material waste and formulate strategies to minimize material waste by applying lean construction principles to building construction projects. The research sample was 15 small-scale contracting companies in Gianyar with 2 to 3 respondents in each company, namely directors, site managers and implementers. Data collection using questionnaires. The data processing technique used is factor analysis and focus group discussion. The test results show that there are 10 indicators of the causes of material waste that often occur, namely, the design does not adjust the size of the available materials, lack of knowledge about construction implementation techniques, drawings with volume calculations are not well integrated, construction materials cannot be stored for a long time, excessive mixture of wet materials, distant material storage locations, incorrect use of conventional formwork, lack of periodic checks related to work results, installed material specifications are not appropriate, lack of attention to material specifications on site. The results of the focus group discussion found that the strategies to reduce material waste based on the application of lean construction principles are training for workers involved, scheduling good material procurement, using standard components available on the market by taking into account modules that can be applied, increasing communication with various parties in exchanging information through discussion forums, checking work results and material specifications regularly.

Emission of carbon footprint from building construction materials: A review

Abstract The construction industry, a cornerstone of global development, is also a notable contributor to environmental degradation. A staggering 39% of the total carbon footprint stems from the production and construction processes, emphasizing the urgency to address this issue. This review narrows its focus on residential building construction, a critical segment of the construction sector. Examining the carbon emissions within residential construction unveils the pivotal role played by various construction materials. Concrete, steel, and traditional bricks, while indispensable, contribute significantly to the sector’s carbon footprint. This necessitates a thorough investigation into alternative materials that can mitigate this impact. In this context, the study delves into innovative solutions and alternative materials that hold the potential to substantially reduce carbon emissions. This review emphasizes the importance of recognizing the carbon emissions stemming from construction materials used in residential buildings. It underscores the pressing need to shift towards more sustainable approaches. Identifying and embracing alternative materials is a pivotal measure in addressing the environmental risks linked to building construction. Ultimately, this research adds to the ongoing conversation about sustainable construction methods, to lead the path towards an eco-friendlier and environmentally aware future in residential building construction.

Design, optimization, and autonomous construction of Martian infrastructure including slabs using in-situ CO2-based polyethylene

A crucial development in 21st-century space exploration is the establishment of human settlements on Mars. In recent years, Mars exploration rovers have been deployed, and studies investigating human journeys to Mars have been conducted, with the objective of a human-crewed mission to Mars before 2050. This study presents an innovative approach to designing and optimizing Martian habitats by using in-situ CO2-based polyethylene (PE) as a construction material for Martian buildings and greenhouses. It seeks to develop sustainable and resilient habitats on Mars, leveraging local resources to address the environmental challenges specific to the Martian environment. The research targets several key areas: realistic construction techniques, effective utilization of in-situ materials, and building resilience under the harsh Martian conditions. These conditions include radiation, micrometeoroid impacts, low atmospheric pressure, low gravity, wind storms, temperature extremes, Paschen discharge, and marsquakes. Finite element analysis (FEA) of several pressurized spherical structures is used to design and optimize for minimum material usage, inspired by soap bubbles that naturally stick together with separating walls. The proposed habitat design features a central spherical structure surrounded by nine smaller spheres, optimized for material efficiency. It is demonstrated that utilizing two layers of 0.1 m thick PE and a 0.5 m thick CO2 layer in between them offers significant protection against Martian environmental loads such as radiation shielding and thermal insulation. It facilitates light transmission into the building. This study offers a realistic structural system for buildings and greenhouses that can be constructed using in-situ materials and is suitable for an optimal 539-day stay on Mars. The proposed autonomous robotic arm technology can perform all necessary tasks, from producing PE to automatically assembling the Mars Spherical Building (MSB), including in-place slab printing.

Design of C2S-CS low-calcium system for synergistic improvement of CO2 sequestration capacity and mechanical properties

Low-calcium minerals exhibit significant potential as energy-efficient binder clinker materials, characterized by reduced emissions and enhanced carbon sequestration through accelerated carbonation curing. However, traditional low-calcium binders typically utilize one or two minerals in a straightforward compound form as clinker, resulting in elevated costs, excessive resource consumption, and suboptimal performance. This study developed a novel C2S-CS low-calcium system that integrated γ-C2S, β-C2S, and CS in specific proportions based on their characteristics, utilizing Simplex-centroid designs. Contour maps achieved to assess relationship between performance and mineral composition, while interaction mechanisms were investigated through carbonation products and reaction heat analysis. Furthermore, optimum proportion range of C2S-CS system can be synthesized efficiently and environmentally from solid waste wollastonite tailings in a single step. The results demonstrated that the designed system achieved synergistic improvements in CO2 sequestration capacity and mechanical properties. After 24 h of carbonation curing, it attained a compressive strength of 129 MPa, sequestered 217 kg/t CO2, and exhibited satisfactory durability. This study provides valuable insights for the practical production of low-calcium binders and reveals opportunities for developing sustainable building materials for eco-friendly construction.

Features, reasons, and significance of radon and thoron attributable radiological dose in the indoor environment

Humans receive around 50% of natural radiation dose due to 222Rn (radon), 220Rn (thoron) and their decay products. Several field campaigns measuring these gases and the decay products in different regions of India have been conducted in the recent past. Some of these studies measured indoor activity concentration and/or dose due to these gases and the associated decay products. This work compares the fraction of 222Rn and decay products and 220Rn and decay products in inhalation dose for 10 studies conducted in Uttarakhand state. It is seen that AEDT (annual effective dose due to 220Rn and decay products) for these regions varies between 21 and 48% and it is significantly higher than the averaged worldwide reference value of 6%. Based on elaborative measurements performed in the Bageshwar district (present work), Almora and Nainital districts (our previous campaigns); the reasons for this high value have been explored. It was observed that a higher source term for mud houses could be the main reason for the high AEDT range. Interestingly, preliminary analysis revealed that the fraction is higher for the dwellings situated at higher altitudes thus indicating the role of the unavailability of modern building construction materials at remote locations. The study highlights the significant contribution of thoron in the Indian Himalayas.

Mesoscopic analysis on the coral aggregate reinforced concrete column under axial and eccentric compression

Coral aggregate concrete (CAC) has been identified as a promising building material for reef engineering construction, yet its practical application remains challenging due to incomplete research on the mechanical behaviors of the CAC beam and column components. In this study, a 3D mesoscale modeling approach considering the heterogeneity of CAC was utilized to investigate the mechanical performance of coral aggregate reinforced concrete columns (CARCCs) under axial and eccentric compression. Through numerical delineation of failure processes and damage mechanisms at the mesoscale, comprehensive parametric analysis integrating both numerical simulations and experimental validations were executed to assess the load-bearing capacity of CARCC. Results indicate that the mesoscale model has significant reliability in simulating the deformation and cracking failure behaviors and analyzing the load-displacement relationships of CARCC under axial and eccentric compression loads. When under axial loads, macroscopic cracks in CARCC primarily develop in an oblique manner, precipitating significant concrete spalling and extensive cracking failure along the longitudinal axis. Under eccentric loads, failure advances from crack initiation at load points to abrupt vertical fractures in stressed zones, manifesting a decrement in the load-bearing capacity with escalating eccentricity. Furthermore, the strength grade and reinforcement ratio exert a profound influence on the load-bearing capacity, with disparate impacts under varied loading conditions. It is concluded that reinforcement strategies tailored to specific loading conditions have significant implications for the design and safety of reinforced concrete structures in reef engineering projects.

Data-driven bio-integrated design method encoded by biocomputational real-time feedback loop and deep semi-supervised learning (DSSL)

Today, under the imperatives of synthetic biology (Synbio), material-based design strategies are conceived as biofactories that can recapitulate the functionalities of living systems for developing building materials with controllable structural features. These strategies include biofabrication techniques such as vitro-culturing, Fabrication Information Modeling (FIM), growth parametrization, machinery systems, and genetic programming articulated bioproducts as the construction material for low-carbon buildings. However, these biophysical systems need interactive development by data-oriented models and decision-maker tools that can mine, measure, and re-configure the complexity in biological systems through monitoring and controlling in a higher integration toward systemic decision-making solutions. This research presents a real-time feedback loop as the bio-integrated design method for design and fabrication of Gluconacebacter Xylinus (GX) Bacterial Cellulose (BC) with Transfer Learning (TL) and Deep Semi-Supervised Learning (DSSL) through TensorFlow and Keras Python libraries. The loop started by mining datasets from BC growth via the VGG16 pre-trained model. In this stage, the loop can learn the material behavior over the growth process and attribute features to a measured BC thickness. Based on this attribution, the loop can drive real-time classifying of input datasets to thickness-based classes and guide the Region of Interests (ROIs) to a user-designed thickness till the captured features are fitted to the user-input class features. The training results over 8640 images show a 0.001 learning rate, an average loss of 0.18 (540 total steps), an accuracy of 0.706, and a precision of 0.752 for the feature extractor model. For the classifier, a 0.15 average loss (3375 total steps), an accuracy of 0.829, and a precision of 0.712 demonstrate the models' efficiency in pattern recognition and classification. Also, the loop operation persistently exhibits a more than 50 % precision rate, displaying the loop's high performance in achieving user-designed 3D shapes. This research aims to a transformative shift in bio-integrated design based on feedback loops as the foundational step towards intelligent bio-digital design platforms. Also, this ground can break designing with biological systems based on desired tasks for the new generation of designers called biodesigners.

Порівняння ущільнюваності асфальтобетонної суміші із золою-винесення та вапняковим наповнювачем

Introduction. In Ukraine, about 30 % of all electricity is generated from the combustion of solid fuels — coal, shale, peat. In our country, there are about 15 operating thermal power plants that generate about 5 – 6 million tons of ash and slag waste per year as a secondary product. Thus, the fuel and energy complex waste generated in the furnaces of thermal power plants is a huge accumulation of ash in the form of dusty residues and lumpy sludge, as well as various ash and slag mixtures. These products of high-temperature processing (1 200 – 1 700 ºС) of the mineral part of the fuel are widely used in many countries of the world and, given the global trend towards an increase in the share of the secondary market for the use of waste, it is necessary to predict an increase in the rate of their processing in Ukraine. Problem Statement. The road construction industry is one of the strategic industries of Ukraine, and the issue of quality and availability of basic building materials for road construction is particularly acute now, which is directly related to its high material intensity. The known reserves of high-quality raw materials that could be used as asphalt concrete components are constantly decreasing, so it is necessary to look for alternative sources of raw materials for construction materials and explore the possibility of their use. In this regard, the most effective use of local raw materials is the use of industrial waste, which can be one of the solutions to the problem of lack of raw materials of inorganic origin.

Sustainability-oriented construction materials for traditional residential buildings: From material characteristics to environmental suitability

The increasing replacement of traditional construction materials with modern alternatives often overlooks their superior environmental adaptability and sustainability, resulting in missed opportunities for energy efficiency and carbon emission reductions. This study aimed to address this issue by scientifically evaluating the material properties of volcanic rock from Hainan Island, China, to assess its potential for sustainable building practices in tropical climates. A series of material characterization techniques were employed to analyze the composition and structure of the volcanic rock, including optical profilometry (OP), polarized light microscopy (PLM), X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS), transient plane source technique (TPS), and mercury intrusion porosimetry (MIP). Our findings identified the rock as vesicular cryptocrystalline basalt, with its unique pore structure and mineral composition jointly contributing to a low thermal conductivity of 0.22 ± 0.04 W/(m·K). The pore structure was characterized by closed spherical cavities, needle-like lava fillings, nanoporous surfaces, complex pore-throat networks, and an extensive pore size distribution. These features significantly reduced gas convection and enhanced thermal resistance. Additionally, the rock composition, dominated by the amorphous volcanic glass and scattered hollow skeletal crystalline plagioclase, further diminished heat transfer. These characteristics indicated that Hainan volcanic rock possessed excellent thermal insulation properties, making it highly suitable for energy-efficient construction in hot climates. This study highlighted the potential for traditional materials like volcanic rock to contribute to sustainable building practices and the preservation of cultural heritage.

Structural Integrity, Environmental Sustainability, and Cost-Effectiveness of Fly Ash Bricks

The construction industry and environmental advocates have increasingly focused on sustainable, long-lasting, and cost-effective building materials in modern construction. Clay bricks and concrete, traditional construction materials, are used extensively, but their environmental impact and resource-intensive production processes are raising concerns. Fly ash bricks, created from industrial waste, have emerged as a promising alternative, offering a unique combination of structural integrity, environmental sustainability, and cost-effectiveness, making them an appealing option for the construction industry. Fly ash, a by-product of coal combustion mainly from power plants was previously considered a pollutant and a disposal challenge. However, the innovative use of fly ash in brick production has transformed this waste into a valuable resource. As awareness of sustainability and eco-friendly building practices has grown, fly ash bricks have gained widespread recognition as a greener alternative to traditional materials like clay bricks and concrete blocks

Experimental study on the characteristic values of partial compression perpendicular to the grain of hardwood with edge distance parallel and perpendicular to the grain

AbstractSome hardwoods have a higher density and superior structural performance than softwoods, which are generally used as construction materials in buildings. Therefore, the characteristics of hardwoods are advantageous in their use for wooden joints. However, the effects of the dimensions of hardwood specimens and wood species on the partial compression performance perpendicular to the grain are unclear. In this study, we conducted partial compression tests perpendicular to the grain of hardwoods to clarify the effects of the edge distance and wood species on the characteristic values. The relationships between the partial compression performance perpendicular to the grain and the edge distance perpendicular to the grain of hardwoods were similar to those of softwoods. A significant correlation was observed between the density and the characteristic values of partial compression perpendicular to the grain. There were differences in the fracture morphologies and stress–strain curves between diffuse and ring-porous woods. However, factors other than density and whether the wood is diffuse- or ring-porous are responsible for the differences in the effect of the edge distance on the characteristic values between wood species.

Global Perspectives on Laterite Mining and Extraction and its Environmental Implications for Nigeria

This paper explores the economic, environmental and social aspects of laterite mining techniques in Nigeria and around the world. Tropical and subtropical climates are home to the rich iron and aluminium oxide-containing soil and rock known as laterite. The article examines the several kinds of laterite deposits found in Nigeria, such as siliceous, bauxitic and ferruginous laterites. The economic significance of laterite mining is derived from its contribution to the construction, steel, iron and aluminium sectors. But there are also serious environmental problems associated with laterite mining like soil erosion, water contamination and deforestation. The energy-intensive character of mineral processing may increase emissions of greenhouse gases. Uncontrolled mining operations have the potential to uproot communities, worsen social injustices and fuel violence. This paper highlights the weaknesses of the regulatory framework in Nigeria, including weak enforcement, inadequate community engagement and limited financial provisions for mine closure and rehabilitation, Laterite mining offers economic benefits through the provision of materials for building and road construction as well as the production of aluminium, iron and other valuable minerals. Finally, governments should implement stricter enforcement mechanisms for existing mining regulations.

Enhancing the Mechanical Properties of Green Concrete Blocks Mixture

Abstract Concrete is a very abundant building material and flexible in construction. Yet cement is the main material used in concrete mixture, which consumed a lot of energy and money. Cement is a very un-eco-friendly material when it comes to production and is a main contributor to global warming. On the other hand, Polymers can be toxic to people, fauna, and flora. In the last century, Egyptian citizens complained that the waste has increased, and the inappropriate waste disposal effect the Egyptian health and quality of life. The alternative is to burn the polymers; however, it will produce toxic emissions that will break down the ozone layer. Previous researchers tried to replace cement with an alternative in the concrete mixture. Therefore, this research intends to create a green concrete block with cement-less mixture and use polymers as a binding material in the blocks. This research will follow the experimental method after discussing the properties of the materials. Then a concrete mix will be created, and a percentage of cement will be replaced; thus, making a cheap concrete mixture that has less cement and is more ecological and economical. Tests will be performed to determine if the proposed concrete mixture is suitable for mass production and doesn’t violate the international standards. The performed tests will include compressive strength, tensile strength, and abrasion. finally, a cost analysis will be calculated to compare the construction costs before and after using the proposed concrete mixture.

The Effect of Iron Sand (Wale) On The Compressive Strength of Quality ConcreteF'c 26.4 Mpa

Concrete is the most widely used building material in construction, both building and bridge construction. This is supported by the ease of the concrete making process that can be made by various groups, both those who understand concrete mix design and those who have no understanding of concrete at all. The difference between the two is only in the quality and quality of the concrete made. The effect of iron sand on normal concrete constituent materials is carried out using percentages of 0.5%, 5% and 20% of the total volume of natural sand used. In this study, iron sand additives were used to determine the most optimal percentage that affects the compressive strength of concrete with the addition of iron sand material of 0.5%, 5% and 20% of the total volume of natural sand. The review of the analysis of this study is compressive strength with a cylindrical test piece with a diameter of 15 cm and a height of 30 cm. From this study, it can be known that the strength of the concrete produced by the use of iron sand mixture is 0.5%, 5% and 20% of the total volume of natural sand.

Inverse problem method application in building physics numerical optimization: new insight into ideal envelope properties determination

ABSTRACT Building thermal design optimization is pivotal for energy efficiency and built environment improvement. The optimal thermophysical properties for building walls remain ambiguous. This ambiguity stems from the constraints of traditional building physics, which: (1) disjoins the enhancement of wall thermal performance from the building service system management; and (2) relies on the forward method that fails to identify the ideal variable thermophysical property, the solution to which is inherently a function. This study elucidates the optimal temperature-dependent volumetric specific heat ( ρ c p ( t ) ) and thermal conductivity ( k ( t ) ) through the inverse problem and variation method. Illustrative example indicates that the optimal ρ c p ( t ) closely resembles a combination of two ‘ δ ’ functions, while the optimal k ( t ) mirrors a square wave function. Utilizing these ideal thermophysical properties, the building energy consumption can be significantly reduced by 77.1% with the optimized ρ c p ( t ) and 79.9% with the optimized k ( t ) . The ideal thermophysical properties for active buildings differ significantly from those recommended for passive buildings, underscoring that minimal energy consumption does not necessarily imply minimal discomfort. Therefore, the thermophysical properties of active and passive buildings should be optimized distinctly. This research offers valuable insights for defining ideal thermophysical properties of active building walls and construction materials.

Pick the butt up! Upcycling cigarette butts in road building material for sustainable road construction.

Abstract Roads are the lifeline of any nation. They are vital in passenger and freight transportation. Over usage and heavy loads put a lot of stress and strain on the health of the roads. On the other hand, cigarette butts (CB) are discarded unsafely after smoking and persist in nature as the cellulose acetate content in them, which is a microplastic, that does not decompose easily leading to a lot of littering, pollution and toxin dispersal in the environment. This proposed research utilizes the discarded cigarette butts into road construction material increasing its strength, durability and resistance against rutting while reducing costs and thermal conductivity to maintaining better surface temperatures. The utilization of discarded cigarette butts in road construction is a sustainable solution to not only strengthen the roads, but also reduce the negative environmental impact of improper cigarette butt disposal. In contrast to conventional bitumen roads, these roads possess superior toughness along with broad level durability. Multi-pronged approach to research was implemented here that included firstly a thorough literature review, conceiving the research design, conduct of research steps, evaluation of experimental results, and finally drawing conclusions from them. These experiments included retrieval of cellulose acetate from CBs, traditional physical and rheology tests, sieve analysis by Rothfuch’s technique and Marshall stability test. This paper aims to contribute to sustainable development goals by utilizing CBs to strengthen roads and clean the environment by eliminating this litter.

Sustainable Building Construction Materials in the United Arab Emirates: A Review

The construction industry, a major player in economic development, is facing increased pressure to address sustainability concerns amidst rapid population growth and urbanization. With global projections indicating a significant rise in building demand by 2050, sustainability has emerged as a crucial focus area and paradigm shift to enhance environmental friendliness, quality, and project outcomes. The UAE, renowned for its vibrant construction industry, offers a unique context for examining the integration of sustainable practices. The use of sustainable construction practices is growing in the UAE, where the built environment plays a key role in economic growth and environmental stewardship. The United Arab Emirates (UAE) aims to foster long-term sustainability while enhancing the standard of living for current and future generations by integrating social, environmental, and economic aspects within construction projects, while also reevaluating conventional sustainable development frameworks and embracing a triple bottom line approach. This research was conducted to explore sustainable construction material usage and evaluation in the United Arab Emirates. The literature was reviewed for sustainable building construction materials across the UAE in the SCOPUS index from 2014 to 2024, as well as the regional regulations concerning the subject. This study evaluated the increasing trend of sustainable construction material research works, as well as the sound regional parameters of sustainable construction materials implemented across the country. Through an exploration of the significance of sustainable construction materials, this research underscores the multifaceted benefits of locally sourced, recyclable, and renewable materials in reducing environmental impacts, fostering economic and social well-being, and improving overall project performance and project management practices. The construction sector’s role in economic development and its substantial environmental impact are discussed in alignment with sustainable construction materials, sustainable construction practices, and the need to enhance environmental sustainability and create healthier built environments. In the realm of sustainable construction materials, project management knowledge areas encompass a range of factors. These include the properties of materials sourced regionally; the incorporation of recycled content; considerations for indoor air quality, energy, and water efficiency parameters; and how these properties relate to project scopes, scheduling constraints, and challenges. Additionally, the availability of resources and competency levels, quality control standards, specifications, communication strategies, and stakeholder involvement play crucial roles. It is important to assess both the positive and negative risks associated with these elements across construction projects.

Current Developments and Future Directions in Energy-Efficient Buildings from the Perspective of Building Construction Materials and Enclosure Systems

The need to design buildings in compliance with the Paris Agreement goal requirements is urgent, and architects and engineers need to consider energy use and operational and embodied carbon requirements in doing so. Building envelopes will be an important element in the next generation of high-performance buildings and there have been significant advancements in recent years to develop building envelopes that help mitigate the building carbon emissions through energy-conserving low-embodied carbon or carbon-sequestering solutions. The key objective of this article is to present an overview of the state-of-the-art in the field of energy-efficient low-carbon buildings with a focus on envelope systems. This article provides a survey of the literature on energy use and carbon emissions of the United States building stock, presents recent advancements in energy-conserving building envelopes, and highlights reuse–reduce–sequester strategies that mitigate the embodied carbon of buildings. As materials are critical in reducing the energy consumption and carbon emissions of buildings, this paper also presents developments on diverse materials and building envelope solutions that have been effective in creating high-performance buildings, from insulation materials to phase-change materials and aerogels. Finally, the characteristics of a selected number of progressive net-zero-energy guidelines such as Passive House Institute (PHI) standards, Passive House Institute US (Phius) standards, the PowerHouse standard, and the BENG standard are discussed. The findings of this work highlight the increased focus on the design, construction, and engineering strategies that aim to mitigate the carbon emissions of buildings based on a holistic whole-life carbon mitigation approach.

Experimental assessment of modal properties of hybrid CFRP-timber panels

Hybrid timber composites are becoming increasingly widespread to efficiently enhance timber performance. While carbon fibre reinforcement has been explored for strength in timber structures, its impact on vibration performance remains understudied and is crucial as mass timber buildings extend their spans and heights. This work explores the effect of carbon fibre reinforcement on the vibration performance parameters of CLT floor systems. Natural frequency, mode shape, damping and stiffness parameters are evaluated from experimental testing using the Natural Excitation Technique (NExT) combined with the Eigensystem Realization Algorithm (ERA) and robust techniques for selection of physical dynamic properties, verified against numerical finite element models. The findings reveal that, in the case of three-ply Cross-laminated Timber (CLT) panels with depths ranging from 115 mm to 135 mm, introducing reinforcement at ratios below 0.67% led to an enhancement in frequencies, registering an increase of 6% to 11%, although not explicitly accounting for changes in environmental conditions. Moreover, these reinforced panels showed a relevant increase in effective flexural stiffness, ranging from 15% to 22%, when compared to their unreinforced counterparts. This means an improved maximum span of around 4%–6% within current design limits for timber floors influenced by vibration performance. These findings enhance the understanding and design of high-performance composite timber floors, promoting the use of renewable building materials in construction.