Browsing by Author "Zouaoui R. Harrat"

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A Sustainable Multi-Criteria Optimization Approach for the Energy Retrofit of Collective Housing in Algeria Using the ELECTRE III Tool
(Springer Nature, 2025-05-08) Nahla Hilal; Nesrine Chabane; Abderahemane Mejedoub Mokhtari; Malika Kacemi; Zouaoui R. Harrat; Naida Ademovi´; Marijana Hadzima-Nyarko
Abstract: This study proposes a sustainable multi-criteria optimization framework for the energy retrofit of collective residential buildings in Algeria, particularly those constructed between the 1970s and 1980s. Through on-site surveys, energy consumption analysis, and seasonal temperature measurements, the high energy demand of these buildings was confirmed. Using EnergyPlus simulations based on Meteoblue weather data, 16 retrofit strategies were assessed—incorporating various insulating materials applied internally or externally (via rendering or cladding). The ELECTRE III decision-making tool was employed, supported by the Simos Revised Framework (SRF) for weighting environmental, economic, and social criteria. Results demonstrate that all strategies significantly reduce energy demand—by up to 72.5%, with reductions reaching 94.4% in winter and 43.5% in summer, depending on insulation type and placement. Improvements in indoor thermal comfort were also observed, with exterior insulation beneath cladding offering the best performance during winter, while exterior rendering also proved effective in the summer. The ELECTRE III analysis identified rock wool and polyurethane with fiber cement cladding as optimal insulation solutions. The proposed approach supports national energy policies and aligns with the Sustainable Development Goals (SDGs), offering a replicable model for large-scale building retrofits in similar climatic and architectural contexts.
Optimizing Urban Thermal Comfort Through Multi-Criteria Architectural Approaches in Arid Regions: The Case of Béchar, Algeria
(Sustainability, 2025-08-25) Nahla Hilal; Radia Benziada; Malika Kacemi; Abderahemane Mejedoub Mokhtari; Naima Fezzioui; Zouaoui R. Harrat; Walid Mansour; Mohammed Chatbi; Md. Habibur Rahman Sobuz
Abstract Urban planning in arid climates must overcome numerous nonclimatic constraints that often result in outdoor thermal discomfort. This is particularly evident in Béchar, a city in southern Algeria known for its long, intense summers with temperatures frequently exceeding 45 ◦C. This study investigates the influence of urban morphology on thermal comfort and explores architectural and digital solutions to enhance energy performance in buildings. This research focuses on Béchar’s city center, where various urban configurations were analyzed using a multidisciplinary approach that combines typomorphological and climatic analysis with numerical simulations (ENVI-met 3.0 and TRNSYS 16). The results show that shaded zones near buildings have lower thermal loads (under +20 W/m2), while open areas may reach +100 W/m2. The thermal comfort rate varies between 22% and 60%, depending on wall materials and occupancy patterns. High thermal inertia materials, such as stone and compressed stabilized earth blocks (CSEBs), reduce hot discomfort hours to under 1700 h/year but may increase cold discomfort. Combining these materials with targeted insulation improves thermal balance. Key recommendations include compact urban forms, vegetation, shading devices, and high-performance envelopes. Early integration of these strategies can significantly enhance thermal comfort and reduce energy demand in Saharan cities
Thermal Performance of Ferrocement Slabs Reinforced with Recycled PET Fibers
(Springer Nature, 2025-04-05) Nahla Hilal; Abdulkader I. Al-Hadithi; Jamal A. Khalaf; Farah A. Al-Fahdawi; Zouaoui R. Harrat; Taher A. Tawfik
This study aimed to identify the optimal ratio of polyethylene terephthalate (PET) fibers to enhance the structural performance of ferrocement slabs, particularly under varying high-temperature conditions. The research examines the effects of PET fibers on the hardened properties of ferrocement mortar, as well as how both PET fibers and elevated temperatures (25 °C, 100 °C, 200 °C, 400 °C, and 600 °C) influence the impact and mechanical behavior of the material. To achieve this, four volumetric proportions of PET fibers (0%, 0.5%, 0.75%, and 1%) were first used to identify the optimum PET content, which was found to be 0.75%. The impact and mechanical behavior of ferrocement slabs were then investigated using the optimized mix. To evaluate the impact behavior, a total of 25 two-way slabs of 500 mm × 500 mm × 50 mm were prepared and tested. The parameters were (a) fiber content (0% and 0.75%), (b) layers of steel wire mesh reinforcement (0, 2, and 4 layers), and (c) elevated temperatures (25 °C, 100 °C, 200 °C, 400 °C, and 600 °C). These were organized to have five different slab configurations: zero reinforcement layer (0L) and zero fiber (0F) (0L-0F); 2L-0F, 4L-0F, 2L-0.75F, and 4L-0.75F. Each of these slabs was tested under the five selected elevated temperatures, making the 25 specimens needed. The same parameters were repeated to evaluate the flexural behavior of ferrocement slabs using 25 one-way slabs with dimensions of 1200 mm × 150 mm × 50 mm. The results indicated that PET fibers decreased density and ultrasonic pulse velocity while increasing water absorption. At a PET fiber content of 0.75%, the compressive and flexural strengths increased by 17.85% and 5.79%, respectively, after 28 days. Strength loss was minimal up to 200 °C, but significant reductions were observed beyond 400 °C. The optimal performance was found in slabs with 0.75% PET and two layers of reinforcement at 200 °C, displaying improved flexural strength, toughness, and ductility. At 600 °C, the breakdown of the plastic fibers resulted in a substantial performance decline. Overall, the findings show that PET fibers enhance ferrocement performance up to 400 °C but experience degradation at higher temperatures.