Geopolymers are a sustainable alternative to Portland cement, with the potential to significantly reduce the carbon footprint of conventional cement production. This study investigates the valorization of industrial waste iron powder (IP) as a fine filler in geopolymers synthesized from volcanic tuff (VTF). Composites were prepared with IP substitutions of 5%, 10%, and 20% by weight, using sodium hydroxide and sodium silicate as alkaline activators. Microstructural and phase analyses were conducted using scanning electron microscope coupled with energy dispersive X-ray spectroscopy (SEM-EDS), X-ray fluorescence (XRF), X-ray diffraction (XRD), and differential scanning calorimetry (DSC), while rheological properties, compressive strength, and flexural strength were assessed. The impact of curing temperatures (25 °C and 80 °C) on mechanical performance was evaluated. Results revealed that air content increased to 3.5% with 20% IP substitution, accompanied by a slight rise in flow time (0.8–2 s). Compressive and flexural strengths at 25 °C decreased by up to 22.48% and 28.39%, respectively. Elevated curing at 80 °C further reduced compressive and flexural strengths by an average of 45.30% and 64.68%, highlighting the adverse effects of higher temperatures. Although these formulations are not suitable for load-bearing applications, the findings suggest potential for non-structural uses, such as pavement base layers, aligning with sustainable construction principles by repurposing industrial waste and reducing reliance on energy-intensive cement production.

Construction and public works sites generate a significant amount of waste that is often costly to dispose of. To reduce the environmental impact and promote sustainability, recycling and recovering this waste is increasingly being recognized as a viable solution. This paper presents the findings of an experimental program investigating the feasibility of using brick and road demolition waste as concrete components. By substituting a portion of sand and cement with recycled materials, this study compares the properties of the reference concrete with concrete containing varying amounts of brick waste and road demolition debris. The obtained results demonstrate that the produced concrete with up to 40 % recycled content achieved a compressive strength exceeding 20 MPa after 28 days. This study suggests that recycled brick and road demolition waste could be a sustainable and economical substitute for conventional aggregates. Incorporating these materials into concrete reduces the cement content while maintaining or even improving the fresh and hardened properties of the concrete. However, it is crucial to limit the use of road demolition sand to 10 %, crushed brick fines to 20%, and brick sand (CBS) to 30% to ensure optimal performance.

The recycling of waste in civil engineering is important as long as it reduces costs and protects the environment. In several countries of the world, different wastes have been used to replace cement or aggregates, such as mineral admixtures, powders and fibers. The aim of this work is to study the influence of fibers from factories and lathing workshops on concrete slump, compressive strength and 3-point flexural strength. The tests have been carried out on concretes containing different types of fibers: stretched steel fibers, fine steel fibers, looped steel fibers and looped aluminium fibers, in proportions varying from 1% to 3% by weight of aggregate. The results show that the behaviour of the concrete in the fresh and hardened state is different depending on the fiber type and content. Fiber distribution analysis was carried out to support the discussion of the results using Gwyddion software.

The development of the building materials industry in Algeria and worldwide has opened up new commercial opportunities for waste recovery. Using recycled materials and natural resources such as expanded clay aggregates are increasingly seen as a solution for the future to meet the gap between production, consumption and environmental protection. The present study investigates the effect of expanded clay aggregate (ECA) on a concrete slump, porosity, softening coefficient, compressive strength, and Freeze-thaw durability. Tests were conducted according to Russian National State Standard (GOST) 10060-2012 of concrete mixtures with expanded clay aggregate (ECA). A total of 7 mixtures were prepared. One is considered a reference mixture based on limestone aggregates. The other six mixtures were prepared by replacing the limestone aggregates with expanded clay aggregates, using two substitution rates (15%, 30% by weight) and three aggregates sizes (Sand 0/4, Gravel 8/16, and 16/25) while maintaining the same w/b ratio. The results indicate that ECAs can be used for concrete production. Furthermore, concrete containing 30% ECA (0/4) has the best properties and is the most freeze-thaw resistant than the other mixtures with ECA.

Sciendo provides publishing services and solutions to academic and professional organizations and individual authors. We publish journals, books, conference proceedings and a variety of other publications.

In the field of metal construction, cellular beams represent an attractive solution to meeting the various technical and economic constraints, especially for large-span buildings. In particular, they allow components linked to the construction to pass through their openings (ventilation ducts, electrical threads, etc.) and thus contribute to significantly reducing the thickness of the floors. However, the use of such beams requires special attention to comply with the regulations in force, in order to guarantee stability and behavior in line with the challenge of preserving the structures. This article focuses on the analysis of the measures of agreement between experiment and computation programs (strength of materials, Robot structures, and Inflexion-EF) results of the beams with circular cuts in their webs (IPE A 100), supported simply and subjected to a concentrated load. The experimental results show that the vertical displacement resulting from transverse compression is induced by various factors: length, cuts in their webs, location of the load, and stiffening of the beams. The comparison of experimental and theoretical results demonstrates the importance of experimental tests in validating theoretical results.