Mohamed H. Zakaria, Sabry Fayed, Mohammed T. Nagib
et al.
Abstract Centrally pull-out experiments were used to investigate the bond behaviour of steel rods implanted in steel fibre reinforced recycled aggregate self-compacting concrete (SSR). SSR, recycled aggregate concrete (RAC), and natural aggregate concrete (NAC) were all looked into. RCA replacement rates of 0, 30, 50, and 100% were investigated. Pull-out experiments were conducted with 12-mm-diameter ribbed steel rebars. The concrete cover thickness was established at 5.75 at the bar diameter ratio, and the embedding distance of the rebar was set to 10 times the rebar diameter. This work’s main objective is to improve SSR bonding performance by employing a steel mesh fabric (SMF) cylinder. This mesh was positioned concentrically at the same length as the bonding distance of the rebar. The diameters of the conducted SMF cylinders were different (4 and 6 time bar diameter). In addition, SMF was used in two distinct densities. SMF reinforcement ratios were calculated to be 0, 2.33, 3.04, 3.5, and 4.5%. The influence of RCA content, silica fume, steel fibre, and SMF ratio on ultimate bond strength, slip, local bond–slip response, failure mode, ductility, and stiffness of pull-out specimens was investigated. The steel rods implanted in SSR-samples exhibited higher peak ductility and bond strength at RCA = 100%, with maximum growth ratios of 284.7% and 70.2%, respectively, compared to RCA samples that were made of 100% RCA. In addition, when RCA in SSR samples increased, the ultimate slips at peak bond stresses decreased. Ultimate bonding capacity and ductility of steel rods embedded in SSR samples improved by about 45% when SMF ratio reached 4.5%. The bond stiffness decreased as RCA rose, with a falling ratio of 68.5% at 100% RCA. Bond stiffness enhanced as a result of silica fume and steel fibre, with a maximum increase ratio of 181.7% at RCA = 100%. Several models have been presented to predict the ultimate bond strength of RAC and SSR by analysing the effects of concrete type, RCA replacement ratio, concrete cover thickness, bonded length, bar surface qualities, and SMF confinement.
Systems of building construction. Including fireproof construction, concrete construction
Abstract Chlorine bypass dust (CBPD) from cement kilns shows significant heterogeneity due to variations in kiln operation and alternative fuels, hindering its reuse in construction materials. This study characterizes nine CBPD samples and applies water washing and mineral carbonation to evaluate their homogenization efficiency. The novelty of this study is that it (i) compares differently supplied CBPDs, (ii) quantifies the homogeneity of their physical, mineralogical, thermal and chemical properties, and (iii) identifies that mineral carbonation effectively stabilizes the metastable Ca-containing phase into CaCO3. While washing removed up to 89.6% of chloride, it increased heterogeneity in Ca-bearing phase content. In contrast, carbonation removed up to 96.1% of chloride and produced a uniform CaCO3-rich phase (> 96%), improving homogenization efficiency. Although lead (Pb) leachability remained inconsistent, other heavy metal leachabilities were lowered than the environmental limit. Thus, mineral carbonation effectively homogenized the metastability of CBPD.
Systems of building construction. Including fireproof construction, concrete construction
Mohammed Abdulkareem Adisa, Samuel Oshadare, Yassar Yusuf
Abstract The global accumulation of approximately 1.5 billion discarded tires annually presents a critical environmental challenge, necessitating innovative recycling strategies in the construction sector. This study investigates the valorization of Recycled Steel Fibers (RSF) recovered from waste tires as a sustainable mechanical reinforcement in concrete. While traditional concrete is limited by inherent brittleness and low tensile capacity, the incorporation of RSF aims to mitigate these deficiencies through a multi-scale crack-bridging mechanism. Concrete mixtures were prepared with RSF dosages of 0%, 1%, 2%, 4%, and 6% by weight of cement. The experimental results demonstrate that while workability decreases with higher fiber content, stabilizing at a slump threshold of 20 mm for dosages of 4% and 6% due to fiber interlocking, the mechanical enhancements are substantial. Compressive strength improved by up to 22.2%, while tension-dominated properties saw the most significant gains, with split tensile and flexural strengths increasing by 44.7% and 47%, respectively. Highly robust regression models (R 2 > 0.97) and error analyses (RMSE < 0.09 MPa) validate the predictive accuracy of the strength gains. Furthermore, a sustainability analysis reveals that substituting industrial fibers with RSF reduces the carbon footprint by 11.2% and enhances the Eco-Efficiency Index by 43.9%. These findings confirm that high-dosage RSF-reinforced concrete is a technically viable and environmentally responsible solution for resilient infrastructure, offering a net economic benefit of approximately USD 26,500 per 1000 m3.
Systems of building construction. Including fireproof construction, concrete construction
Currently, building construction planning has developed, including the precast system. A precast system is a system where some or all of the components are printed first in a factory or other place outside the project location according to their size and then placed and installed in the planned place. The conventional system is a system where all structures that use concrete construction, the concrete is cast directly on the spot.The aim of this research is to determine the cost of concrete construction when using conventional concrete construction systems and precast systems and to determine the time required for work from both systems. The method used in this research is qualitative descriptive research. The data in this research is secondary data in the form of supporting data collected through literature studies taken from literature, previous writings, data from the internet and so on. This secondary data is to obtain institutional data, this data is obtained from related parties, one of which is the Project Cost Budget Plan.From the results of calculations and data analysis that have been carried out, it is found that the total cost of implementing a conventional concrete system is IDR 327.868.106,03, while the total cost of implementing a precast concrete system is IDR. 380.058.394,38. The time difference between the two systems is 11 days. The comparison results of the two systems show that the costs for renting heavy equipment such as cranes are large, but in terms of time efficiency, the precast system is faster to implement than the conventional system because the components can be made or ordered before the construction project is implemented.
Mahboobeh Hemmati, Tahar Messadi, Hongmei Gu
et al.
The main purpose of this study is to quantify and compare the embodied carbon (EC) from the materials used or designed to build the Adohi Hall, a residence building located on the University of Arkansas campus in Fayetteville, AR. It has been constructed as a mass timber structure. It is compared to the same building design with a steel frame for this study. Based on the defined goal and scope of the project, all materials used in the building structure are compared for their global warming potential (GWP) impact by applying a life cycle assessment (LCA) using a cradle-to-construction site system boundary. This comparative building LCA comprises the product stage (including raw material extraction, processing, transporting, and manufacturing) plus transportation to the construction site (nodule A1–A4, according to standard EN 15804 definitions). In this study, GWP is primarily assessed with the exclusion of other environmental factors. Tally®, as one of the most popular LCA tools for buildings, is used in this comparative LCA analysis. In this study, the substitution of mass timber for a steel structure with a corrugated steel deck and concrete topping offers a promising opportunity to understand the GWP impact of each structure. Mass timber structures exhibit superior environmental attributes considering the carbon dioxide equivalent (CO2 eq). Emissions per square meter of gross floor area for mass timber stand at 198 kg, in stark contrast to the 243 kg CO2 eq recorded for steel structures. This means the mass timber building achieved a 19% reduction in carbon emissions compared to the functional equivalent steel structure within the building modules A1 to A4 studied. When considering carbon storage, about 2757 tonnes of CO2 eq are stored in the mass timber building, presenting further benefits of carbon emission delays for the life span of the structure. The substitution benefit from this construction case was studied through the displacement factor (DF) quantification following the standard process. A 0.28 DF was obtained when using mass timber over steel in the structure. This study provides insights into making more environmentally efficient decisions in buildings and helps in the move forward to reduce greenhouse gas (GHG) emissions and address GWP mitigation.
The increasing pressure on urban systems and buildings in South Africa caused by rapid urbanization and climate change necessitates innovative approaches, including Nature-based Solutions (NbSs), to address environmental and societal challenges. As such, this study aimed to determine the dynamic role of NbSs in shaping the sustainability of South Africa’s built environment. Using a quantitative approach, the data were collected via a questionnaire survey, which targeted built environment professionals. Data analysis involved reliability testing, confirmatory factor analysis, and Spearman rank order correlation. The survey showed that green roofs, rainwater harvesting, cool roofing and pavements, as well as living walls, have received above-average attention in the country, while agricultural byproducts from concrete construction, bioswales, rain gardens, and algae-based materials are yet to be explored in the delivery of green buildings and sustainable urban areas. Overall, deploying NbSs promises positive environmental, societal, and economic impacts. The findings emphasize the need for stronger policies and regulations that promote the adoption of underutilized NbSs within the South African built environment. Theoretically, this study contributes to the existing discourse on sustainable development in South Africa. As the nation grapples with diverse environmental and social issues, this study becomes timely, as it provides crucial insights into how NbSs can address some of these challenges.
The 6 February 2023 Kahramanmaraş earthquakes in Turkiye, which measured 7.8 and 7.5 moment magnitude (Mw) per the United States Geological Survey (USGS), affected 13 provinces and over 15 million people, according to the Turkish Government. The Earthquake Engineering Research Institute’s (EERI) Buildings Reconnaissance Team visited the populated centers as well as small towns in Turkiye that were most affected by these earthquakes. The team focused on understanding the overall structural performance of buildings, including correlation with maximum spectral acceleration and peak ground velocity at nearby ground motion recording stations. This article discusses the vulnerability of concrete buildings, which constitute most of the building stock in the region, performing an overall assessment of structural systems as well as components. More than 160 individual buildings at about 130 sites were observed. The construction period of these buildings varied from pre-2000s to as new as a few years old. Turkish building codes underwent significant changes after the 1999 Kocaeli earthquake and most recently in 2018. The findings in this article include not only the behavior of critical gravity and lateral structural elements but also the participation of non-structural elements in the seismic response of the structure, such as infills, non–load-bearing partitions, and perimeter unreinforced masonry infill walls. This article discusses the findings from field observations related to design, detailing, and construction practices. Findings illustrating the seismic performance of building systems and individual components such as floor slabs, beams, columns, shear walls, and foundations, with key takeaways to improve the seismic design guidelines, construction, and inspection practices, are summarized.
The Indian construction industry is grappling with an affordable housing crisis, prompting the exploration of alternative construction methods. Traditional techniques, such as brick and concrete, are increasingly labour-intensive and costly. This paper investigates the potential of Light Gauge Steel Frame (LGSF) construction, particularly when combined with Ferron, a composite material that enhances structural integrity while reducing costs and construction time. The LGSF-Ferron system eliminates the need for formwork and offers benefits like increased fracture resistance and sustainability, positioning it as a viable alternative to reinforced concrete. Despite its advantages, the adoption of LGSF-Ferron in India remains in its early stages, with critical quality and safety challenges that must be addressed. High-quality assurance and safety management standards are essential to mitigate risks such as financial losses and injuries during on-site construction. This study emphasises the importance of stringent quality control measures, including material quality checks, precision manufacturing, structural engineering compliance, and ongoing quality assurance throughout construction. Through a comprehensive analysis of the benefits, challenges and solutions associated with LGSF-Ferron modular construction, this research aims to provide insights into its role in promoting sustainable and affordable housing in India. Key findings highlight the necessity for pre-engineered components, rigorous on-site inspections and adherence to regulatory standards to ensure successful implementation. By addressing quality and safety concerns, LGSF-Ferron technology can significantly contribute to more efficient building practices and help alleviate the ongoing housing crisis in India. The paper's findings show that LGSF-Ferron is a sustainable, cost-effective alternative, requiring better quality control, safety, and workforce training for adoption in India. Major Findings: The study identifies LGSF-Ferron modular construction as a sustainable, cost-effective solution to India’s housing crisis, emphasizing the need for rigorous quality control, safety standards, and skilled workforce training for effective adoption.
Colonial architecture in Madiun City reflects a complex interaction between political power, technological development, and environmental adaptation during the Dutch colonial period. As an administrative center of the Madiun Residency, the city experienced architectural transformation from the monumental Indische Empire style to the more rational and functional Nieuwe Bouwen approach. This study examines architectural styles, building systems, and tropical adaptation strategies embedded in colonial buildings in Madiun. The findings indicate that early colonial architecture emphasized symmetry, massive walls, and classical proportions, while later developments adopted reinforced concrete structures and simplified forms. Despite technological modernization, colonial buildings consistently integrated passive design strategies, including wide verandas, high ceilings, large openings, and strategic orientation to optimize ventilation and thermal comfort. The use of local materials combined with European construction techniques demonstrates a pragmatic response to tropical climate conditions. These architectural characteristics position colonial buildings in Madiun as valuable historical artifacts and as relevant references for contemporary tropical architecture. Understanding their design principles contributes to heritage conservation efforts and offers insights into sustainable architectural practices rooted in historical experience.
Hussein M. Hamada, Alyaa Al-Attar, Mand Kamal Askar
et al.
Abstract Magnesium oxychloride cement (MOC) is a promising alternative to Portland cement due to its superior mechanical strength and lower carbon footprint. However, its poor water resistance remains a major barrier to widespread use. This review critically evaluates recent and emerging modification strategies to overcome this limitation, with a specific focus on improving water durability through chemical and physical enhancements. The novelty of this work lies in the comprehensive analysis of synergistic effects from compound additives, particularly combinations of organic acids and phosphates, on MOC performance. For example, integrating 1% tartaric acid (TA) and phosphoric acid (PA) was found to increase compressive strength to 87 MPa and 100 MPa, respectively, while significantly improving the softening coefficient and reducing degradation under prolonged water exposure. The study also highlights the role of nano-modifications, fiber reinforcements, and polymer emulsions in densifying the microstructure and enhancing long-term durability. These insights offer a quantitative and practical roadmap for optimizing MOC formulations and advancing its use in sustainable construction applications.
Systems of building construction. Including fireproof construction, concrete construction
Abstract The massive expansion of global construction projects has caused a shortage of river sand (RS) as a construction raw material, necessitating the development of alternative materials to alleviate this pressure. In this study, ferrochrome slag (FS) and dune sand (DS) were utilized as composite aggregates to completely replace RS in building materials. Systematic tests were conducted to evaluate the effect of gradation on the flowability and mechanical properties of mortars with composite aggregates, clarifying the influence mechanism through microscopic physical phase tests. The test results show that the grading optimization improves flowability by 12.8–15.9% and enhances the 28-day compressive strength of mortars by 20.5–23.2%. The optimized gradation with a DS proportion of 0.3 has the highest performance, with 28-day compressive and flexural strengths of 59.81 MPa and 8.30 MPa, which are 29.4 and 11.9% higher than those of RS aggregate mortar, respectively. Microstructural analysis reveals that optimized gradation reduces porosity by 7.4–10%, leading to denser structures with fewer cracks and pores. The optimal use of DS and FS as alternative aggregates significantly reduces costs and potential carbon emissions, as the cost efficiency (C P ) and ECO2 efficiency (CI) values of the optimized mixture decreased by 47.3 and 27.7% respectively, compared to the control group. The materials developed in this study exhibit excellent engineering application potential, and the performance-based material optimization method provides a theoretical basis and practical reference for the design of alternative building materials made with solid waste.
Systems of building construction. Including fireproof construction, concrete construction
In-situ compressive strength and rate of degradation over time are key factors in determining the longevity and dependability of reinforced cement concrete (RCC) constructions. The rebound hammer test and destructive core testing are two examples of traditional techniques that are time-consuming, expensive, and sometimes inappropriate for newly built or important buildings. This study describes the design and development of a small, inexpensive, and non-destructive concrete testing tool that may be used on-site to assess the strength and remaining service life of concrete components. In order to measure and visualise data in real time, the system interfaces a number of sensors, including piezoelectric vibration sensors, a temperature sensor, a capacitive moisture sensor, and an accelerometer-gyroscope module, with an microcontroller and an OLED display. In order to determine compressive strength, the device analyses vibration responses and ultrasonic pulse velocity (UPV) from the piezoelectric sensors. Temperature and moisture data are used as adjustment factors to increase accuracy. To evaluate material stiffness and ageing behaviour, the accelerometer-gyroscope module offers further vibration and damping data. Both the instantaneous strength and the predicted ageing factor of the tested RCC element are calculated by processing the recorded values using empirical and regression-based models. According to experimental validation, the suggested device offers improved mobility, shorter testing times, and easier operation while achieving near agreement with conventional non-destructive testing (NDT) techniques. The device's small size and multi-sensor fusion capabilities make it perfect for field engineers and construction workers to perform continuous inspections of concrete constructions in both new and existing buildings.
Daniel Obokhai Uduokhai, Baalah Matthew, Patrick Garba
et al.
The growing demand for affordable and climate-resilient housing in low-income communities across the Global South has intensified the need for innovative construction approaches that balance cost efficiency, environmental responsibility, and social welfare. This study presents a techno-economic evaluation of renewable-material construction systems—such as compressed stabilized earth blocks (CSEB), bamboo composites, recycled aggregates, and bio-based insulation—applied to low-income housing development. It investigates the performance, lifecycle costs, structural safety, and sustainability benefits of renewable materials relative to conventional concrete-based construction. Findings demonstrate that renewable-material technologies can reduce embodied energy, carbon emissions, and long-term maintenance costs, while enabling localized production and job creation within community-based supply chains. The analysis also highlights affordability advantages derived from reduced transportation requirements, modular prefabrication, and adaptive design approaches tailored to local climatic conditions. Despite these advantages, several techno-economic barriers persist, including limited industrial scaling, lack of standardized testing and certification, skill gaps in implementation, and market skepticism regarding durability and performance. The study emphasizes the importance of supportive policies—such as green building codes, tax incentives, and microfinance innovations—to enhance market competitiveness and drive broader adoption. A multi-criteria evaluation framework is proposed to guide decision-makers in assessing material choices across technical, economic, and socio-environmental dimensions. Ultimately, renewable-material construction provides a viable pathway to expand safe, sustainable, and dignified housing access for low-income populations while contributing to national climate goals and circular economy strategies. Strengthening research, capacity building, and public-private partnerships will be essential to accelerating this transition and unlocking widespread socio-economic benefits.
Portland cement concrete (PCC) is a versatile and widely used construction material renowned for its strength and durability. The mechanical properties of PCC, including compressive strength, flexural strength, and splitting tensile strength, play a pivotal role in ensuring the safety and sustainability of structures such as buildings, bridges, and dams. Traditionally, the determination of PCC's compressive strength involves destructive testing of standard-size concrete cylinders until they fail. While nondestructive evaluation (NDE) techniques are available for assessing these properties, they often require direct contact between the sensor and the concrete surface, making them less efficient and practical compared to remote sensing techniques. In this paper, we applied three NDE techniques for estimating the mechanical properties of concrete, including synthetic aperture radar (SAR), ultrasonic pulse velocity (UPV), and a rebound hammer. We manufactured a total of 48 laboratory concrete cylinders (diameter = 3", height = 6"). These cylinders were created with different water-to-cement ratios (0.4, 0.45, 0.5, and 0.55) with a mix design ratio of 1:2:3 for cement: sand: gravel (by mass). Four dates of compressive testing were considered (7-day, 14-day, 28-day, and 96-day). Before these cylinders were tested by destructive compression test, they were measured by three NDE techniques. A 10GHz SAR system with a 1.5 GHz bandwidth, a 54kHz UPV system, and a Schimdt rebound hammer were used to inspect those cylinders. Our experimental results reveal a discernible relationship between the compressive strength of concrete and the NDE data. The increase of cylinder age resulted in the increase of compressive strength of PCC cylinders. SAR image parameters, UPV curves, and rebound hammer curves showed correlated patterns. This technique has the potential to provide a nondestructive and efficient means of assessing concrete strength and durability, with significant implications for the construction industry in ensuring the safety and sustainability of various structures.
Dmitry V. Fedotkin, Arkady S. Tarbeev, Vladimir N. Baklykov
et al.
Methods and means for extinguishing the most common flammable liquids such as diesel fuel, gasoline, etc. (water-insoluble hydrocarbons), in most cases are not effective in extinguishing fires of water-soluble polar liquids. Their physico-chemical properties have a great influence. Modern regulatory documents define methods and means for extinguishing polar flammable liquids, but there are no scientifically confirmed normative numerical values or they are based on small-scale fire foci. Based on the analysis of foreign and domestic regulatory and technical literature, as well as research conducted in this field, there are determined the main postulates for the fire tests methodology. The scientifically based data obtained during the research will form the basis for the provisions of the regulatory document «Storage warehouses for water-soluble liquids. Fire safety requirements».
Systems of building construction. Including fireproof construction, concrete construction