For decades, there has been an increasing interest in the development of Additive Manufacturing (AM) in both the construction industry and civil engineering. The rapid evolution of this field requires a review to maintain a global vision. This has led to the emergence of large robotic arm and gantry systems capable of printing building components using various materials such as concrete, including supplementary cementitious materials or natural fibres. Other less recent technologies, such as Fused Deposition Modelling and Laminated Object Manufacturing contribute to the production of components for construction. AM offers several advantages including automated production processes and design flexibility for complex geometry. This article provides an overview of the current state of AM in construction, including an examination of engineering and AM processes, concretes and reinforced materials, advanced materials, and the development of new applications. Additionally, the article discusses recent standards for 3D Concrete Printing. It is aimed at those seeking a comprehensive understanding of AM and its applications in construction 5.0.
Composite materials use combinations of materials that cannot meet the desired structural performance in the architectural field alone. The new Atatürk Cultural Centre had to be reconstructed on a site in Taksim Square where there are heavy vehicle and pedestrian traffic, and close to the city's rail transport network. This congestion compelled the entire construction team to adopt construction technologies that diverged from traditional techniques. The new building had to remain within some of the references of the old building, while at the same time making a new architectural and engineering step forward. A construction technology using a combination of reinforced concrete and steel components was the solution to many problems. The objective of this study is to evaluate the benefits of the reinforced concrete-steel composite system, to show that it is a more suitable construction technology for buildings with unique architecture under special conditions such as restricted building sites, large spans, seismic risk zones, and thus to draw the attention of the construction sector to the advantages of this system. To this end, an examination of the projects of the New AKM building was conducted, encompassing the collection of data through interviews with static and architectural offices, as well as electronic sources. The structural system of the building was then analysed using the 'illustrative case study' method. The study concluded that the utilisation of composite construction systems offers numerous advantages, including enhanced building load capacity, seismic resilience, accelerated construction processes, and reduced labour errors in special-use buildings located in urban centres.
Concrete for ambitious engineering projects, including bridges, must meet certain requirements related to strength, water resistance, frost resistance and plasticity. The objective of the article is to improve the efficiency of concrete for bridge structures. The compositions of high-strength building composites have been optimized with a reduction in the proportion of the clinker component. The densest packing of filler particles has been achieved, providing a self-compacting effect during hardening. The compositions of building composites have been optimized at the macro-, micro- and nanolevels to obtain a high-density matrix packing and increase the strength of the composite (including taking into account the granulometric analysis of fillers and the choice of superplasticizer). New properties of high-strength building composites (rheology of highly concentrated dispersed systems, shrinkage deformations, workability, setting time, etc.) have been studied. The results of fresh properties of the developed mixtures showed their compliance with the P5 grade, which indicates that they have good transportability to the place of manufacture of bridge structures. The study of the physical and mechanical characteristics of cement composites (average density, porosity, compressive and bending strength, elastic modulus, frost resistance, shrinkage, Poisson's ratio) showed that the obtained materials can be effectively used for the construction of critical structures, including bridges.
Abstract The long-term durability of concrete is essential for sustainable construction and reducing carbon emissions. A key factor affecting durability is the ingress of hazardous substances, making the understanding of ionic diffusion in concrete crucial. While ionic diffusion is significantly affected by the microstructure of cement paste, existing diffusion models often oversimplify this microstructure by neglecting particle internal pores (PIPs). This simplification can lead to inaccuracies in predicting ionic diffusivity and, consequently, the long-term performance of concrete structures. This study addresses this critical gap by developing a hydration-diffusion simulation method to investigate the effects of PIPs on ionic diffusion in hydrated tricalcium silicate (C3S), a primary constituent of cement clinker. Our simulations revealed that: (1) the effects of PIP size distribution and particle porosity (PP) on ionic diffusion depended on the water content, water-to-solid ratio, solid C3S content, and hydration age; (2) at early ages, in hydration systems with a fixed C3S content or water-to-solid ratio, higher PP would result in lower ionic diffusivity in hydrated C3S paste. However, contrasting conclusions emerged under conditions of fixed water content; (3) the effects of PIPs on the ionic diffusion in hydrated C3S also varied with hydration age and water-to-solid ratio.
Systems of building construction. Including fireproof construction, concrete construction
Abstract Sudden failure of reinforced concrete (RC) beams with substandard tension lap splices due to low resistance to flexure is a critical issue that needs to be addressed. Accordingly, a novel pre-stressing technique is presented in this paper, which offers a promising solution for strengthening RC beams with substandard tension lap splices. The technique involves the use of external steel bolts, load-transferring brackets, and bearing plates. Eleven test specimens sized 100 × 200 × 1500 mm3 were utilized in a series of experimental investigations to assess the effectiveness of the suggested approach. These specimens consisted of one specimen without a tension lap splice, one with a sufficient tension lap splice equal to 60d b, and nine beams with insufficient tension lap splices equal to 25d b. The investigation considered three main variables for eight strengthened specimens: the length of the strengthening plate (L s = 60d b, 80d b, and 100d b), the number of bolts (N b = 2, 3, and 4 pairs), and the pre-stress level in the bolts (PL = 0.1f y, 0.2f y, and 0.3f y). The effects of the proposed strengthening technique on ultimate load (P ult), first cracking load (Pc), deformation behavior, failure pattern, cracks distribution, deflection ductility, flexure toughness, and elastic stiffness were investigated. The findings demonstrated that the pre-stress approach considerably enhanced the ultimate load (61.52–218.65%) and first crack load (80.15–106.40%) of the strengthened specimens compared with the control specimen. In addition, there was a notable improvement in flexural toughness and elastic stiffness, with an average value of 205.5% and 101.35% for all strengthened specimens, respectively. Also, strengthened RC beams showed considerable improvements in ductility, with an average increase in peak (μ p) and ultimate deflection (μ uf) indices of 120.16% and 94%, respectively. In general, the novel pre-stressing technique enhances the structural performance of the beams by increasing their load-carrying capacity, improving ductility, and enhancing crack resistance.
Systems of building construction. Including fireproof construction, concrete construction
During the war, more than 160,000 buildings were damaged as a result of military operations in Ukraine, including 125 railway stations. This determines the importance of the task of restoring damaged construction sites. The primary important stage of restoration work is the inspection of such sites. At the same time, the necessary volume of work is established, as well as capital costs for its restoration. In most such sites, reinforced concrete structures are important components, the reliability of the structure as a whole depends on the condition of the concrete. Therefore, the quality of restoration, economic costs for restoration also depend on the accuracy and reliability of the results of the concrete inspection. In Ukraine, a methodological basis has been developed for the System for Ensuring the Reliability and Safety of Construction Sites. According to the provisions of the System, suitability, in our case, for restoration work is established through compliance with the technical condition of the structures. The conditions of compliance are also determined by regulatory documents. For the examination and study of the characteristics of concrete in structures, the ultrasonic pulse method is determined, along with others. The main advantages of this method are: the possibility of studying the characteristics of concrete in almost any part of the structure, the necessary accuracy and reliability of the measurement results. The main disadvantage of devices that implement this method is the impossibility of conducting measurements in the case of operating construction machines, during the operation of which elastic vibrations are excited in the concrete under study. This is due to the fact that by their physical nature such extraneous vibrations are similar to ultrasonic ones. As a result of superimposing extraneous vibrations on ultrasonic ones, both the reliability and accuracy of the measurement results may decrease. Based on the need to adhere to the schedule of restoration work carried out under the current state of war, it is undesirable to stop them for the duration of the study of concrete. Existing ultrasonic measuring devices produced both in Ukraine and in foreign countries do not have protection against extraneous elastic vibrations. In order to ensure the conduct of concrete research using the ultrasonic method in conditions of operating construction equipment, an improved device has been developed that is free from such a drawback.
Global warming and climate change are pressing issues caused by human activities, including those in the construction industry. The use of building materials, utensils, and unprofessional techniques is threatening both human health and environmental health. In response, the sustainable green building design approach is essential to mitigate these adverse impacts, aiming to reduce energy consumption and greenhouse gas emissions compared to traditional buildings. The present study aimed to assess the design of sustainable green buildings using discrete approaches, including eco-friendly building materials, solar energy, and rainwater harvesting system focusing on a site of 262 m2 in Vempalli Mandal, Andhra Pradesh, India. The study was conducted in a selected suitable building area, considering the key resources of material, energy, and water. The project aimed to enhance the opportunities for building sustainability from various perspectives to achieve optimal results compared to conventional buildings. The assessment includes the use of GGBS and fly ash in concrete, resulting in a reduction in cement usage, and the implementation of solar panels that can generate required energy annually. The study found that sustainable green buildings can significantly reduce energy consumption, with potential energy savings of Rs. 1,15,200 annually, greenhouse gas emissions, and environmental degradation. The use of eco-friendly building materials, solar energy, and water harvesting can reduce energy costs, improve indoor air quality, and promote sustainable development. Incorporating eco-friendly materials and systems can lower carbon dioxide emissions by up to 295 tons over 25 years, equivalent to planting 472 teak trees. The present study contributes to the existing literature on sustainable green buildings by assessing the design of sustainable green buildings using discrete approaches. The study’s findings highlight the importance of incorporating eco-friendly building materials, solar energy, and water harvesting into building design to promote sustainability. The study’s results have implications for policy-makers, architects, engineers, and construction companies seeking to develop sustainable buildings that minimize environmental impacts. The study’s novelty lies in its comprehensive approach to assessing sustainable green buildings by considering multiple factors, including material selection, energy efficiency, and water harvesting. The study’s findings have practical applications in the construction industry, as they provide a framework for designing sustainable green buildings that can reduce environmental impacts and promote sustainable development.
The overall aerial building formwork is an independently invented support equipment in China, specifically designed for the construction of concrete structures in super high‐rise buildings over 200 m. The integration of a concrete placing‐boom and integrated aerial building formwork equipment plays a crucial role in this new type integrated system. This article provides a comprehensive summary and analysis of the integrated connection structure between the existing concrete placing‐boom and the overall aerial building formwork equipment. It also presents an innovative design for a lightweight unit‐type formwork concrete placing‐boom integrated platform, along with detailed explanations of its structure design and construction process. Furthermore, calculations and analyses were conducted to determine maximum stress and deformation under various conditions such as climbing, steel bar binding and formwork synchronization operation and concrete pouring by using MIDAS finite element software. The results demonstrate that the maximum stress and deformation meet the control requirements effectively. This article invents a novel overall aerial building formwork equipment integrated with a concrete placing‐boom, compared to the existing integrated platform, the lightweight unit‐type formwork concrete placing‐boom integrated platform offers advantages including flexible assembly, strong structural applicability, excellent safety performance, high construction efficiency, superior load‐bearing capacity as well as overall performance enhancement. These features make it more suitable for meeting the specific construction needs of super high‐rise buildings over 200 m, and provided a new equipment for the construction of super‐high‐rise reinforced concrete core.
Alam Alhuda Ali Albalula Mukhtar, Abdelhameed Hammed Mohammed Ali
This study evaluates the structural behavior of a 20-story concrete office building with a rigid frame system under varying wind loads. The analysis is conducted using ETABS software at wind speeds of 40, 60, 80, and 100 mph. The internal forces, including deflection, shear, and overturning moments, are assessed under these conditions. The results demonstrate compliance with ACI318-19 code requirements and address critical factors like deflection limits and stability. The study further highlights environmental impacts, neighboring building effects, and wind movement in the width direction, ensuring safe and efficient high-rise building designs. It has been concluded that deflection, shear forces and overturing moments increase at a similar rate with the increase in wind speed. Additionally, the drift caused by wind does not pose a significant risk compared to that caused by earthquakes, for this reason, the American code does not specify a limit for wind induced drift as the H/500 limit is an approximate value derived form previous experiences. This Study recommends that future studies on this system continue, taking into account seismic loads. And should include a comparison between this system and other systems resistant to wind and seismic loads focusing just on cost and method of construction in our country Sudan.
The demand for rapid, cost-effective, and sustainable infrastructure solutions has driven significant advancements in prefabricated concrete technology over the past decade. This study explores recent innovations in the design, production, and implementation of prefabricated concrete components within modern infrastructure projects, including bridges, buildings, and transportation systems. Emphasis is placed on modular construction techniques, high-performance materials, digital fabrication methods, and connection systems that enhance structural efficiency, durability, and construction speed. Case studies from urban infrastructure developments illustrate how prefabrication reduces construction time, minimizes on-site labor, improves quality control, and decreases environmental impact through material optimization and waste reduction. Furthermore, the integration of Building Information Modeling (BIM) and automation in precast fabrication facilities has streamlined the design-to-production workflow, enabling greater precision and customization. The paper concludes that prefabricated concrete technology plays a pivotal role in addressing the growing infrastructure needs of rapidly urbanizing societies while supporting the global transition toward more sustainable construction practices.
In this article, we give a construction of the (un-)stable motivic homotopy category of an algebraic stack in the spirit of Morel-Voevodsky. We prove that this new construction agrees with the stable motivic homotopy category defined by Chowdhury and D'Angelo. As an application, we extend Bachmann's spectral rigidity theorem to algebraic stacks. Moreover, we extend the construction of the framed motivic homotopy category to algebraic stacks and prove Hoyois' Reconstruction Theorem in this setting. Finally, we discuss an extension of the formalism of cocomplete coefficient systems à la Drew-Gallauer to algebraic stacks.
Structural fireproof classification is vital for disaster risk assessment and insurance pricing in Japan. However, key building metadata such as construction year and structure type are often missing or outdated, particularly in the second-hand housing market. This study proposes a multi-task learning model that predicts these attributes from facade images. The model jointly estimates the construction year, building structure, and property type, from which the structural fireproof class - defined as H (non-fireproof), T (semi-fireproof), or M (fireproof) - is derived via a rule-based mapping based on official insurance criteria. We trained and evaluated the model using a large-scale dataset of Japanese residential images, applying rigorous filtering and deduplication. The model achieved high accuracy in construction-year regression and robust classification across imbalanced categories. Qualitative analyses show that it captures visual cues related to building age and materials. Our approach demonstrates the feasibility of scalable, interpretable, image-based risk-profiling systems, offering potential applications in insurance, urban planning, and disaster preparedness.
Construction robotics increasingly relies on natural language processing for task execution, creating a need for robust methods to interpret commands in complex, dynamic environments. While existing research primarily focuses on what tasks robots should perform, less attention has been paid to how these tasks should be executed safely and efficiently. This paper presents a novel probabilistic framework that uses sentiment analysis from natural language commands to dynamically adjust robot navigation policies in construction environments. The framework leverages Building Information Modeling (BIM) data and natural language prompts to create adaptive navigation strategies that account for varying levels of environmental risk and uncertainty. We introduce an object-aware path planning approach that combines exponential potential fields with a grid-based representation of the environment, where the potential fields are dynamically adjusted based on the semantic analysis of user prompts. The framework employs Bayesian inference to consolidate multiple information sources: the static data from BIM, the semantic content of natural language commands, and the implied safety constraints from user prompts. We demonstrate our approach through experiments comparing three scenarios: baseline shortest-path planning, safety-oriented navigation, and risk-aware routing. Results show that our method successfully adapts path planning based on natural language sentiment, achieving a 50\% improvement in minimum distance to obstacles when safety is prioritized, while maintaining reasonable path lengths. Scenarios with contrasting prompts, such as "dangerous" and "safe", demonstrate the framework's ability to modify paths. This approach provides a flexible foundation for integrating human knowledge and safety considerations into construction robot navigation.
We present explicit quantum channels with strictly sub-additive minimum output Rényi entropy for all $p>1$, improving upon prior constructions which handled $p>2$. Our example is provided by explicit constructions of linear subspaces with high geometric measure of entanglement. This construction applies in both the bipartite and multipartite settings. As further applications, we use our construction to find entanglement witnesses with many highly negative eigenvalues, and to construct entangled mixed states that remain entangled after perturbation.
Abdalwhab Abdalwhab, Ali Imran, Sina Heydarian
et al.
The construction industry has long explored robotics and computer vision, yet their deployment on construction sites remains very limited. These technologies have the potential to revolutionize traditional workflows by enhancing accuracy, efficiency, and safety in construction management. Ground robots equipped with advanced vision systems could automate tasks such as monitoring mechanical, electrical, and plumbing (MEP) systems. The present research evaluates the applicability of open-vocabulary vision-language models compared to fine-tuned, lightweight, closed-set object detectors for detecting MEP components using a mobile ground robotic platform. A dataset collected with cameras mounted on a ground robot was manually annotated and analyzed to compare model performance. The results demonstrate that, despite the versatility of vision-language models, fine-tuned lightweight models still largely outperform them in specialized environments and for domain-specific tasks.
Building construction requires important amounts of freshwater, thus depleting the already stressed natural water resources. This issue could be addressed by using recycled water in construction and in building systems. However, integrating greywater recycling systems is limited by complexity, costs, vulnerability to environmental fluctuations, and coordination of policymakers, developers, and construction practitioners. Here, we review recycled water systems in buildings with focus on case studies of successful implementations, policies, recycled water treatment in buildings, and health aspects. Compared to conventional tap water, the incorporation of recycled water enhances the consistency and workability of reclaimed water concrete by 12–14%, and it increases concrete viscosity by 11% and yield stress by 25%. We discuss the intricacies of building water recycling systems, with emphasizing on conserving water, mitigating environmental impact, and enhancing economic efficiency. Challenges include water quality assurance, dual piping infrastructure, and regulatory compliance. Government interventions, including incentives, mandates, and subsidy policies, emerge as drivers for widespread adoption. Technological advancements, such as membrane filtration and advanced oxidation processes, are examined for strengths and limitations.
This paper presents an overview of the scholarly works employing the life cycle assessment (LCA) approach to evaluate the environmental impact of construction and demolition waste (CDW) fine fractions derived from concrete elements throughout their life cycle. Unlike conventional studies, this work addresses the challenge of reducing the carbon footprint associated with CDW-based building materials, emphasizing environmental impact mitigation. The study highlights that approximately 30% of CDW is landfilled, 50% is recycled, and 20% is used as fill material, underscoring the potential for increasing recycling rates through improved processing techniques and management practices. In the reviewed studies, most research has been conducted in Europe, Asia, the USA, and China. The primary and secondary data sources for the life cycle inventory (LCI) vary depending on the study region and locality. By exploring innovative practices and critical stages in CDW fine fractions utilization for concrete components, the study aims to contribute to greener construction practices and sustainable resource management. The distinctive aspect of this research lies in its comprehensive review of CDW-based aggregates, binders, and alternative cementitious materials, highlighting the significance of sustainable energy resources and transportation strategies in enhancing the sustainability of CDW-derived concrete. Key findings highlight the necessity of sustainable energy for pretreatment and optimized transportation strategies, including route planning and vehicle selection, to produce greener CDW fine fraction-based building materials. Additionally, the study suggests key steps and parameters required for defining the system boundary and preparing the inventory for conducting an LCA of building materials based on CDW fine fractions. Through a detailed analysis of environmental burdens at each production stage, this study seeks to promote the adoption of greener concrete solutions worldwide. The use of CDW in concrete production promotes environmental sustainability and greener concrete regardless of the region.
Caroline Silva Araújo, E. A. M. Ferreira, D. Costa
Purpose Tracking physical resources at the construction site can generate information to support effective decision-making and building production control. However, the methods for conventional tracking usually offer low reliability. This study aims to propose the integrated Smart Twins 4.0 to track and manage metallic formworks used in cast-in-place concrete wall systems using internet of things (IoT) (operationalized by radio frequency identification [RFID]) and building information modeling (BIM), focusing on increasing quality and productivity. Design/methodology/approach Design science research is the research approach, including an exploratory study to map the constructive system, the integrated system development, an on-site pilot implementation in a residential project and a performance evaluation based on acquired data and the perception of the project’s production team. Findings In all rounds of requests, Smart Twins 4.0 registered and presented the status from the formworks and the work progress of buildings in complete correspondence with the physical progress providing information to support decision-making during operation. Moreover, analyses of the system infrastructure and implementation details can drive researchers regarding future IoT and BIM implementation in real construction sites. Originality/value The primary contribution is the system proposal, centralized into a mobile app that contains a Web-based virtual model to receive data in real time during construction phases and solve a real problem. The paper describes Smart Twins 4.0 development and its requirements for tracking physical resources considering theoretical and practical previous research regarding RFID, IoT and BIM.