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Item 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. TawfikThis 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.Item The influence of waste polypropylene fibers on the behavior of sustainable reinforced concrete beams(John Wiley & Sons, 2025-02-04) Nahla Hilal; Sulaiman Nayef Ahmed; Ayad S. Aadi; Mohammed Nawar; Salih Taner Yildirim; Nadhim Hamah SorPlastic waste has recently become one of the most important environmental issues. Plastic fibers in concrete provide a long-term solution to plastic waste management. Concrete is a rigid material and has superior compressive strength but has poor tensile strength. Using waste plastic fibers in concrete can address its brittleness and low tensile strength. In this study, waste polypropylene fiber (WPF) prepared from discarded plastic tapes in reinforced concrete (RC) beams was used. WPF of 5 mm width was added to the concrete at a volumetric percentage of 1%. The fibers were added at different lengths (50, 70, and 90 mm) individually, and then all lengths were mixed randomly. This study provides the results of laboratory tests conducted to evaluate the mechanical properties of the WPF-RC. Additionally, a comparison of RC beams with the same percentage of reinforcement but varying lengths of WPF in the tensile zone was provided. The criteria for the flexural test were determining the ultimate load, the yield, and the first cracking as well as the deflections associated with these loads. Evaluations of the energy absorption index, ductility, and failure modes were also carried out. The WPF enhanced the ultimate load by 5%, the deflection at the ultimate load by 33.26%, and the splitting tensile strength by 51.47% for the concrete. Additionally, the load– deflection relationships demonstrated that concrete beams reinforced with WPF tend to deflect more before failing. The energy absorption index capacity is increased by 94.36% and ductility by 25.83% for the beam reinforced with 1% WPF, mixed randomly at mixing randomly lengths. This possible enhancement of RC beam performance based on the WPF can promote the use of sustainable concrete in many structural applications based on the WPF.Item Compared Efect of Nano Date Pits and Nano Sunfower Seed Shells on Properties of Green Cement Mortar(Springer Nature, 2025-01-14) Nahla Hilal; Ahmed A. Alani; Meyyada Y. Alabdulhady; · Zouaoui R. Harrat; · Faisal G. AL‐MaqateAgricultural waste, generated in massive quantities each year, poses environmental challenges and ofers an opportunity to enhance eco-friendly practices in construction. The current study aimed to address the concerns of minimizing agricultural waste and reducing the environmental impact associated with traditional cement production, including shortage in resources and carbon emissions. Thus, the feasibility of incorporating nano date pits and nano sunfower seed shells as sustainable additive materials in cement mortar were investigated. Three diferent nanomaterials content were used: (1, 3, and 5%), these nano additives were added into mortar mixtures to assess their infuence on fresh and hardened characteristics, as well as on the microstructure. Fresh density and fowability were used as a measure to evaluate workability, while hardened properties such as density and compressive strength were utilized to evaluate the structural integrity. Microstructural analyses were also conducted through scanning electron microscopy (SEM) and X-ray difraction (XRD). The experimental results revealed that nano sunfower seed shells decreased fowability by 8–42%, while nano date pits had a lower impact, with reductions from 4 to 25%. Fresh density decreased with the increasing of nanomaterial content, particularly with the sunfower seed shells due to their lighter weight and higher porosity. For hardened characteristics, dry density dropped by approximately 20% in sunfower seed shell mixtures, while date pit mixtures density was reduced gradually, supporting the development of lightweight mortars. Furthermore, the mixture with 1% nano date pits has enhanced compressive strength by up to 22% at 28 days, attributed to the pozzolanic activity of nano date pits that refned the microstructure. SEM and XRD analyses revealed considerable interactions between the nano additives and the cement matrix. Furthermore, these analyses showed dense hydration products and enhanced contact zones between cement and aggregates, promoting structural integrity. The current study fndings assure the potential of nano agricultural waste materials to improve sustainable mortar formulations, ofering lightweight, durable, and eco-friendly alternatives to traditional cement-based mortars.Item Effect of glass and nylon fibers on drying shrinkage of alkali activated blast furnace slag mortars(Taylor & Francis, 2024-08-13) Nahla Hilal; Salih Taner Yildirim; Ahmet Kaan YildirimThe environmental consequences of Portland cement (PC) manufacturing have prompted the exploration of alternative binders, such as the alkali activation of blast furnace slag (BFS), which is generated as a byproduct during the extraction of iron. While alkali-activated blast furnace slag (AAS) binders have some benefits over regular PC binders, they also suffer from disadvantages such as significant drying shrinkage. The study investigated the impact of Na dosage and curing conditions on alkali-activated blast fur nace slag mortar (AASM). The consistency of the specimens was tested for fresh, hardened properties, and was conducted. The optimum Na dosage and curing conditions were selected. In the second stage, 0.1% and 0.2% glass and nylon fibers were added to the selected optimum mortar. Consistency, fresh, mechanical, and durability properties tests were con ducted on the fiber mortars. The results showed that increasing the Na content increased the compressive and flexural strengths of AASM speci mens. Thermal curing provided high compressive and flexural strengths, whereas fiber addition reduced water absorption and drying shrinkage. The drying shrinkage value was reduced by 26.82 % for AASM specimens with 0.2 % nylon fibers by volume compared to AASM without fibers.Item SEM analysis, durability and hardened characteristics of eco-friendly self-compacting concrete partially contained bentonite and waste walnut shells(Taylor & Francis, 2024-12-09) Nahla Hilal; Nadhim Hamah Sor; Meyyada Y. Alabdulhady; P. Jagadesh; Kadhim Z. NaserReusing waste materials as aggregate in self-compacting concrete (SCC) may reveal green construction materials. Walnut shell (WS) can be used in place of aggregate in SCC. This study utilized five dissimilar volume fractions of WS as fine aggregate ranging from 8% to 40%, containing bentonite clay powder constant as 10% of cement weight. The SEM analysis, fresh proper ties and hardened characteristics of all SCC mixtures were assessed. Additionally, the impact of a 5% concentration of H2SO4 and MgSO4 solution for a month on the compressive and splitting tensile strengths and density were studied. The workability of all the LWSCC mixes satisfied standard requirements except of L-Box result; nevertheless, as the WS content increased, the workability of the LWSCC mixtures declined. Following the exposure period for both sulphate attacks, all characteristics of LWSCC mixes were reduced. In contrast to the control mixture, the SEM analysis shows that when WS was added in greater amounts, the concrete became less dense and had more voids. Furthermore, the statistical analysis was per formed by using two-way variance (ANOVA) technique which revealed that the effects of all independent variables on the strength and other properties of cement mortar were significant under all experimental conditions.