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Item Durability and hardened characteristics of cement mortar incorporating waste plastic and Polypropylene exposed to MgSO 4 attack(Elsevier, 2024-12) Nahla Hilal; Osamah Mohammed G. Al-Kerttani; Sheelan Mahmoud Hama; Nadhim Hamah Sor; Qais Sahib Banyhussan; Taher A. TawfikAnnual waste plastic disposal has grown, harming nature. Utilising this waste in concrete production may help preserve building resources. This study tested cement mortar with polyvinyl chloride (PVC) and polypropylene (PP) substituted for sand aggregate at 0, 5, 10, 15, and 20 %. The samples were nevertheless exposed to a 10 % and 20 % MgSO4 solution for a month. The properties of both fresh and hardened materials under these cir cumstances have been evaluated and contrasted with those evaluated under typical circumstances. For mixes including PP and PVC, the flow diameter increased. The rounded plastic particles provided fewer contact surfaces and less friction among mixtures, which reduced water consumption and improved workability, leading to an increase in slump flow. As the amount of plastic aggregate increases, the compressive strength decreased. Moreover, this pattern might be explained by the weakening of the bond between the surfaces of the plastic aggregate and cement paste. The hydration of cement may also be hampered by the hydrophobic properties of plastic aggregate. Like compressive strength, the splitting tensile strength decreased as the replacement level of plastic ratio increased regardless of its type under all conditions (normal and exposing to MgSO4 ). PP and PVC fine aggregate in mortar increases sorptivity under all situations. Following screening, those circumstances and PVC have the most impact on compressive strength. increasing PVC and PP at 10 % for each of them leads to lower values of compressive and tensile strength. An optimization process was implemented to determine the optimum value of PVC, PP, and MgSO4 . It shows that using PVC of 3.9 %, PP of 10.1 %, and MgSO4 leads to maximum compressive and tensile strength with the minimum cost and CO2 emissions.Item Studying the usability of recycled aggregate to produce new concrete(Faculty of Engineering, Cairo University (CUFE), 2024-06-11) Nahla Hilal; Ola Adel Qasim; Mohammad I. Al Biajawi; Nadhim Hamah Sor; Taher A. TawfikOne of the most significant environmental issues worldwide is garbage, particularly waste from construction materials, which is generated in substantial numbers. How ever, in the building industry, the significant extraction of natural resources such as cement, natural sand, and natural gravel poses a critical environmental challenge, depleting these resources at an alarming rate. There are some solutions that devel oped countries are resorting to, namely the division of construction waste into groups, where it is reused under the name of recycling construction waste to produce new, environmentally friendly building materials. The aim of this research includes a labora tory process study as it includes the use of the following ratios: 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100%, under the process of replacing coarse plain aggregates includ ing coarse recycled aggregates and studying the most important mechanical proper ties of concrete. This research was carried out using fresh concrete properties such as workability tests and hardened concrete properties such as compressive strength, splitting, and flexural tensile strength examined at the durations of 7, 14, and 28 days. The research includes the investigation of the three main properties of concrete. After conducting the tests, the results have shown that the main property of recycled concrete is lower strength than that of conventional concrete, but it can be said that it is within the limits that can be used for construction. The results also showed that com pared to normal aggregates, development in the recycled aggregate percentage rates reduces the operational workability of concrete. The research proved that the maxi mum decrease in compressive, flexural, and tensile strength, density and the slump were 19.4, 18.3, 19.6, 19.5, and 25.0% respectively compared to the control concrete samples. Keywords: Compressive strength, Flexural strength, Tensile strength, Natural aggregate, Concrete, Recycled material, Waste materialsItem Mechanical performance of eco-friendly self-compacting concrete (SCC) mixtures and two-way slabs partially containing cement kiln dust as cement replacement and internally reinforced with waste plastic mesh(Elsevier, 2024-08) Nahla Hilal; Ayad S. Aadi; Sheelan Mahmoud Hama; Weiwen Li; Nadhim Hamah Sor; Walid MansourA large quantity of cement kiln dust (CKD) is produced annually during the production of Portland cement. The majority of the produced CKD remains unused except in specific cases related to soil stabilization projects. The current research investigates the production of self-compacting concrete (SCC) mixtures, in which CKD is used as a substitute for cement in different weight proportions, 3 %, 6 %, 9 %, 12 %, and 15 %. The hardened mechanical properties of SCC, such as compressive strength, splitting tensile strength, and flexural strength, as well as the fresh state characteristics (i.e., slump flow diameter, T500, V-funnel, and L-box tests), were recorded and compared with the control mixture which was entirely cast using cement. Results revealed that with an increase in the CKD content beyond 6 %, the slump flow diameter of SCC mixtures significantly decreased. Also, the increase ratios in the V-Funnel flow time for self-compacting concrete mixtures, when replacing cement with CKD ratios of 3 %, 6 %, 9 %, 12 %, and 15 %, were 13.3 %, 30 %, 46 %, 58 %, and 66.7 % respectively, compared with the reference mixture. Additionally, the impact behavior of two-way SCC slabs cast using CKD ratios ranging from 3 to 15 % and internally strengthened using various patterns of recycled plastic mesh was inves tigated. Strengthening the SCC slabs using two layers of recycled plastic grids proved to be effective in preventing the projectile from penetrating the whole thickness of the SCC slabs, regardless of the CKD content.Item The Impact Resistance of Fire Shooting for Self-Compacted Concrete Slabs Containing Ceramic Powder and Reinforced by Novel Waste Nylon Fiber(Annales de Chimie - Science des Matériaux, 2024-08-04) Nahla Hilal; Aseel S. Mansi; Ayad S. Aadi; Taghreed Khaleefa Mohammed Ali; Haider A. AbdulhameedIn the present study, nylon waste fibers (NWF) were utilized for the first time to improve the impact resistance of self-compacting concrete (SCC) slabs against pistol shooting. Six ratios of NWF were used in the range of (0.25- 1.5 at an increment of 0.25) % with three different lengths (50, 70, and 90) mm for each ratio. The fresh properties, compressive strength, and Utara sonic pulse velocity (UPV) of SCC were also measured. The results indicate the positive role of NWF in improving compressive strength. However, the fresh properties are affected negatively by using NWF. The best impact resistance of the slab occurred when 1% of NWF with a length of 90 mm was utilized.Item Characterization and use of activated carbon synthesized from sunflower seed shell in the removal of Pb(II), Cd(II), and Cr(III) ions from aqueous solution(Springer Nature, 2024-03-13) Nahla Hilal; Ibtihal A. Mawlood; Wahran M. Saod; Ahmed S. Al‑Rawi; Abdulsalam M. AljumialyIn this work, carbon-based nanomaterials such as active carbon which is prepared from com mon sunflower (Helianthus annuus) seed shell, and the characterization of the activated carbon NPs were studied using FTIR (Fourier transform infrared spec troscopy), XRD, SEM, EDS, and DTA techniques. Activated carbon NPs have been used in the adsorp tion of Pb(II), Cd(II), and Cr(III) ions from the aque ous phase. The results showed the highest adsorption efficiency was 99.9%, 92.45%, and 98% for Pb(II), Cd(II), and Cr(III) ions respectively at a tempera ture of 25 °C, pH = 7–9, and a time of 60 and 180 min, in addition to the accordance of the adsorption models for activated carbon with the Freundlich iso therm model at the value of R2 (0.9976, 0.9756, and 0.9907) and Langmuir isotherm model (0.966, 0.999, and 0.9873) of the Pb(II), Cd(II), and Cr(III) ions,Item The influence of nanosunflower ash and nanowalnut shell ash on sustainable lightweight self‑compacting concrete characteristics(Springer Nature, 2024-04-24) Nahla Hilal; Nadhim Hamah Sor; , Marijana Hadzima‑Nyarko; Dorin Radu; Taher A. TawfikThe absence of biodegradability exhibited by plastics is a matter of significant concern among environmentalists and scientists on a global scale. Therefore, it is essential to figure out potential pathways for the use of recycled plastics. The prospective applications of its utilisation in concrete are noteworthy. The use of recycled plastic into concrete, either as a partial or complete substitution for natural aggregates, addresses the issue of its proper disposal besides contributing to the preservation of natural aggregate resources. Furthermore, the use of agricultural wastes has been regarded as a very promising waste-based substance in the industry of concrete manufacturing, with the aim of fostering the creation of an environmentally sustainable construction material. This paper illustrates the impact of nano sunflower ash (NSFA) and nano walnut shells ash (NWSA) on durability (compressive strength and density after exposure to 800 °C and sulphate attack), mechanical properties (flexural, splitting tensile and compressive strength) and fresh characteristics (slump flow diameter, T50, V-funnel flow time, L-box height ratio, segregation resistance and density) of lightweight self-compacting concrete (LWSCC). The waste walnut shells and local Iraqi sunflower were calcinated at 700 ± 50 °C for 2 h and milled for 3 h using ball milling for producing NSFA and NWSA. The ball milling succeeded in reducing the particle size lower than 75 nm for NSFA and NWSA. The preparation of seven LWSCC concrete mixes was carried out to obtain a control mix, three mixtures were created using 10%, 20% and 30% NWSA, and the other three mixtures included 10%, 20% and 30% NSFA. The normal weight coarse aggregates were substituted by the plastic waste lightweight coarse aggregate with a ratio of 75%. The fresh LWSCC passing capacity, segregation resistance, and filling capability were evaluated. The hardened characteristics of LWSCC were evaluated by determining the flexural and splitting tensile strength at 7, 14 and 28 days and the compressive strength was measured at 7, 14, 28 and 60 days. Dry density and compressive strength were measured after exposing mixes to a temperature of 800 °C for 3 h and immersed in 10% magnesium sulphate attack. The results demonstrated that the LWSCC mechanical characteristics were reduced when the percentages of NWSA and NSFA increased, except for 10% NWSA substitution ratio which had an increase in splitting tensile strength test and similar flexural strength test to the control mixture. A minor change in mechanical characteristics was observed within the results of LWSCC dry density and compressive strength incorporating various NSFA and NWSA` contents after exposing to temperature 800 °C and immersed in 10% magnesium sulphate attack. Furthermore, according to the findings, it is possible to use a combination of materials consisting of 10–20% NSFA and 10–20% NWSA to produce LWSCC.Item Durability and Hardened Characteristics with SEM Analysis of Eco‑Efficient Self‑Compacting Concrete Partially Contained Waste Walnut Shell Particles as Fine Aggregate(Springer Nature, 2023-07-23) Nahla Hilal; Hadi H. Edan; Nadhim Hamah Sor; Taher A. TawfikSubstituting waste materials for natural aggregate in SCC can lead to the discovery of ecological building materials. Walnut shell (WS) is one of the agricultural byproducts that can be substituted for aggregate in SCC. In this study, WS was used as a replacement for fine aggregate in SCC by employing five different volume fractions ranging from 8 to 40% in incre ments of 8% while maintaining a constant percentage of limestone powder (10% by weight of cement). All SCC mixtures were evaluated for the fresh properties (slump flow, slump flow duration, V-funnel, L-box, and wet density) tests, hardened characteristics (compressive strength, splitting tensile strength, flexural strength, Schmidt rebound hammer, and ultrasonic pulse velocity) tests, scanning electron microscopy (SEM) analysis, and the effect of H2SO4 and MgSO4 solution with 5% concentration for one month period on the density, compressive and splitting tensile strengths. The hardened properties were performed at 28 and 56 curing periods. The results revealed that the workability and hardened properties of SCC mixtures decreased with increasing WS content, but the workability outcomes were within the standard specifications of SCC, except for the L-box test. The lowest compressive strength of 23.7 MPa was recorded for the mix containing 40% of WS, greater than the lower strength required for structural purposes. On the other hand, the density, compressive and splitting tensile strengths of all SCC mixes decreased after exposure period for both sulphate attacks. The investigation with SEM reveals that the increasing amount of WS produced more voids and less dense concrete compared to the control mix.Item On the Post-Heat Behavior of Cement Mortar Containing Mechanically Modified Ground Coal Bottom Ash(Salud, Ciencia y Tecnología – Serie de Conferencias., 2024-05-31) Nahla Hilal; Fadzli Mohamed Nazri; Haneen Abdel Jabar; Khairunisa Muthusamy; Rahimah Embong; Mohammad I. Al BiajawiCoal is widely recognized as a significant and essential fuel source due to its capacity to undergo combustion and produce heat in many different regions worldwide. Over the course of many decades, there has been a notable rise in power usage among individuals, thus resulting in an upsurge in the utilization of coal. The growth of mankind has a parallel rising trajectory with the utilization of cement in the building industry, as well as a corresponding rise in cement manufacturing. These two phenomena significantly contribute to the escalation of carbon dioxide (CO2 ) emissions and the improper disposal of coal ash, both of which pose significant environmental hazards. Coal-fired thermal power plants generate many waste products from industry, including coal-bottom ash (CBA), which may be effectively used in the production of mortar or concrete. This practice not only promotes the adoption of sustainable construction materials but also encourages the utilization of these wastes. In contrast, it is worth noting that cement manufacture yields a significant quantity of carbon dioxide emissions, so exerting a detrimental influence on the ecosystem. The reduction of environmental deterioration may be achieved by substituting cement with waste products. The substitution of Portland cement with reutilized coal combustion products has the potential to provide significant environmental and infrastructural advantages. This study presents an experimental investigation into the post-heat performance of cement mortars including ground coal bottom ash (CBA). To achieve this objective, an investigation was conducted to assess the strength qualities, residual strength, and mass losses of mortar specimens. These specimens comprised varying proportions (10 %, 20 %, 30 %, and 40 %) of CBA as a substitute for cement. To perform the heating procedure, samples were subjected to temperatures of 200°C, 400°C, and 600°C, which corresponded to room temperatures. The findings indicate that the use of ground CBA up to a proportion of 20 % yields mortar with the maximum value of compressive strength compared with the control sample. The use of a substantial amount of ground CBA has been shown to produce the most significant reduction in mass and decrease in strength when subjected to high temperatures. As a result, the residual strength of concrete experiences a decrease of 33,65 % when exposed to a temperature of 600°C in conventional concrete while for CBA in concrete decreases around 40,9 %. In general, the integration of ground CBA alternatives as an alternative to cement would result in a decrease in the need for the manufacture of cement and the environmental pollution associated with CBA discharge.