From waste to high-performance cement: enhancing mechanical and microstructural characteristics with iron-rich industrial by-products Ahmed S. Ouda, Samah A. Sanad International Journal of Construction Management, 2026 This research explores the valorization of iron-rich industrial waste as a sustainable partial substitute for OPC, aiming to reduce clinker dependence and carbon emissions while enhancing microstructural performance. Cement pastes containing 10–50% iron waste micro-powder were evaluated under water and oven-dried curing to assess mechanical, physical and morphological evolution. The results showed that low substitution levels (≤10%) enhance the filler-nucleation synergy, refining the microstructure by promoting C-S-H formation and pore refinement. In contrast, over-inclusion (≥20%) resulted in dilution and retardation effects, reducing Ca(OH)2 formation and weakening the cementitious matrix. The scanning electron microscopy (SEM) investigation confirmed the transition from dense and continuous OPC gels to porous and discontinuous structures at higher waste content. Among all studied composites, the 10% improved formulation revealed superior strength, microstructural integrity and sustainability potential. This research demonstrates an innovative pathway for the circular utilization of iron-rich waste, contributing to the development of low-carbon, high-performance binders for eco-friendly construction applications.
Novel approach to enhance the efficiency of mortar against radiations by co-incorporation of lead and boron compounds with calcium chloride Hussein Al-kroom, Ahmed S. Ouda, Wageeh Ramadan, Mahmoud Gharieb, Mudar Hamsho, Hamdy A. Abdel-Gawwad Scientific Reports, 2025 Fabrication of heavy density mortar using aggregates reinforced with available solid inorganic chemical additives is of a great importance as a protective layer to mitigate radiations in nuclear facilities. The effect of lead oxide and borax decahydrate on the hydration kinetics was evaluated by determining setting time, leachability and compressive strength. To speed up the reaction, 0.5% calcium chloride was added to all formulations, and then the results were compared to their blank counterparts. Once, the optimal compositions were explored, another batch of mortar were designed to increase efficiency against radioactive sources with different photon energies. After 28 days, bulk density, linear attenuation coefficient, half-value layer, tenth-value layer, and mean-free path in the field of 137Cs and51Co were considered. Similarly, macroscopic effective removal cross-section was evaluated using radioactive source-239Pu-α-9Be. According to the previous literature, adding 0.2% PbO to cement is the optimal ratio without affecting hydration kinetics and phase composition. The study explored that, co-incorporation of PbO with 0.5% CaCl2 increases the ratio to 2.5%, while enhancing physico-mechanical and radiological characteristics against radioactive sources. Also, formulation incorporating 0.5% borax with 0.5% CaCl2 had superior attenuation against neutrons compared to other competitors.
Effect of ceramic tile waste addition on the performance of slag-based geopolymer upon exposure to marine conditions: Physico-mechanical characteristics, and shielding proficiency against ionizing radiation A.M. Abdelmonem, Abdelhalim Azam, Abdalziz Alruwaili, Ahmed S. Ouda, Mohamed Abd Elrahman Sustainable Chemistry and Pharmacy, 2025 The effect of ceramic waste powder (CWP) on the performance of slag-based geopolymer prior and after exposure to marine conditions was evaluated by determining the physical, mechanical and radiological properties. Geopolymers were designed upon partial replacing slag with waste in the range of 5–30%. Bulk density and compressive strength of mixtures in line with ASTM standards were investigated. The radiation parameters, including μ m , μ, HVL, Z eff , N eff , and C eff for photons were verified through Phy-X/PSD in a wide energy range. Fast Neutrons Effective Removal Cross-Sections (FNRCS) and Macroscopic Removal Cross-Section (MRCS) values for fast neutrons were verified through Phy-X/PSD and MRCS software. While, thermal neutron total removal cross-section factors were calculated by NGcal software. However, the energy range was investigated by SRIM (Monte Carlo) software for H + , He ++ and Au + ions. The results revealed that, the mix containing 20% waste immersed in seawater is the most suitable composition for mitigating photons and fast neutrons. In the same vein, the formulation containing 15% waste is the better candidate under normal conditions compared to its counterparts. At the same gamma ray energy, the performance of the seawater-immersed mixtures as photon attenuators is higher than that of their counterparts treated under normal conditions.
Photocatalytic performance of Nb2O5-graphene heterojunction for the degradation of methylene blue Abdulhadi Hamad Al-Marri, Ali Moulahi, Amal T. Mogharbel, Amal M. Al-Mohaimeed, Fatma Janene, Ahmed S. Ouda, Eida S. Al-Farraj, Musaad N. Almaslamani, Mohamed A. Almaslamani, Issam Mjejri Polyhedron, 2024 In this study, a facile hydrothermal method has been successfully applied to elaborate a Nb 2 O 5 and Nb 2 O 5 /reduced graphene oxide photocatalyst with uniform spheres structure for the degradation of methylene blue (MB) under UV irradiation . The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) analysis confirm the formation of the Nb 2 O 5 /reduced graphene oxide heterostructure with high surface area (S BET = 69.21 m 2 .g −1 ). The optical properties shows that the Nb 2 O 5 /reduced graphene oxide exhibited the lower bandgap value of 2.88 eV as compared to Nb 2 O 5 (3.14 eV) with significant redshift and enhance visible light absorption . The photo-catalytic activity of the Nb 2 O 5 and Nb 2 O 5 /reduced graphene oxide photocatalyst for the removal of the methylene blue (MB) under UV–visible illumination was evaluated. The electrochemical impedance spectroscopic (EIS) measurements further elucidate the suppression of photogenerated electrons/holes as the radius of the semicircle significantly decreased in case of heterojunction formation. It was found that the Nb 2 O 5 decorated with reduced graphene oxide sheet showed significantly better photocatalytic efficiency in the removal of methylene blue dye (99.5 % degradation after 1 h of irradiation) than commercial Nb 2 O 5 (20 % degradation after 1 h of irradiation). This result comes from the effective formation of heterojunctions between the reduced graphene oxide and Nb 2 O 5 semiconductor which facilitate the transfer of the photoelectrons from the surfaces of the nanoparticles to the reduced graphene oxide sheets, nanoporous structure with numerous catalytically active sites, superior charge transfer efficiency, and stronger oxidation property of the synthesized nanoparticles .
Characterization, physico-mechanical properties, thermal performance, and adsorptive capacity of porous cement blends containing construction and demolition waste: Deep … AS Ouda, MM Abou-Krisha, EA Abdelrahman, M Gharieb, MM Mokhtar, ... Journal of Building Engineering, 115644 , 2026 2026
From waste to high-performance cement: enhancing mechanical and microstructural characteristics with iron-rich industrial by-products AS Ouda, SA Sanad International Journal of Construction Management, 1-18 , 2026 2026
Examination of thermal loads in M-60 grade high-performance heavy-density concrete for potential use in nuclear facility designs ZA Zaki, AS Ouda, MS Meddah, M Abd Elrahman Progress in Nuclear Energy 192, 106129 , 2026 2026
Towards sustainable radiation protection: hydration, gamma-ray, and neutron shielding of OPC–limestone composites from diverse geological origins AS Ouda Environmental Science and Pollution Research, 1-20 , 2026 2026
Environmental valorization of iron-laden waste: dual application in wastewater treatment and evaluation of the physico-mechanical and microstructural performance of … AS Ouda, SA Sanad, SM Abdel-Moniem Environmental Science and Pollution Research 32 (40), 23009-23028 , 2025 2025 Citations: 2
Anthracite/talc-based porous activated composite loaded with DTAB surfactant for Cr (VI) adsorption: Characterization, performance, and mechanism EA Abdelmonem, ASAAA Sharib, AS Ouda, E Al-Olayan, SH Kenawy, Z Li, ... Journal of the Indian Chemical Society, 101945 , 2025 2025 Citations: 2
Effect of ceramic tile waste addition on the performance of slag-based geopolymer upon exposure to marine conditions: Physico-mechanical characteristics, and shielding … AM Abdelmonem, A Azam, A Alruwaili, AS Ouda, M Abd Elrahman Sustainable Chemistry and Pharmacy 43, 101886 , 2025 2025 Citations: 6
Novel approach to enhance the efficiency of mortar against radiations by co-incorporation of lead and boron compounds with calcium chloride H Al-Kroom, AS Ouda, W Ramadan, M Gharieb, M Hamsho, ... Scientific Reports 15 (1), 929 , 2025 2025 Citations: 2
Insights into the physico-mechanical characteristics and corrosion behavior of high-performance heavy density concrete used in the construction of electro-nuclear power facilities AS Ouda Construction and Building Materials 443, 137838 , 2024 2024 Citations: 7
Effect of activator type and Pozzocrete waste on the mechanical and microstructural properties of eco-friendly geopolymer incorporating electric arc furnace slag AS Ouda, AM Rashad, M Gharieb Geosystem Engineering 27 (4), 171-185 , 2024 2024 Citations: 2
Evaluating the role of feldspar on the resistivity of alkali-activated slag towards seawater attack AS Ouda, M Gharieb Environmental Science and Pollution Research 30 (1), 127-144 , 2023 2023 Citations: 8
Effect of high temperature on physical, mechanical and microstructure properties of alkali-activated slag pastes blended with ceramic waste material AS Ouda European Journal of Environmental and Civil Engineering 26 (10), 4827-4846 , 2022 2022 Citations: 7
An investigation on the performance of lightweight mortar-based geopolymer containing high-volume LECA aggregate against high temperatures AS Ouda, AM Rashad Environmental Science and Pollution Research 29 (18), 26631-26647 , 2022 2022 Citations: 17
Effect of tidal zone and seawater attack on high-volume fly ash pastes enhanced with metakaolin and quartz powder in the marine environment AM Rashad, AS Ouda Microporous and Mesoporous Materials 324, 111261 , 2021 2021 Citations: 40
Behavior of alkali-activated pozzocrete-fly ash paste modified with ceramic tile waste against elevated temperatures and seawater attacks AS Ouda, M Gharieb Construction and Building Materials 285, 122866 , 2021 2021 Citations: 39
A preliminary investigation on gamma-rayattenuation of alkali-activated concrete waste based-geopolymer modified with pozzocrete-fly ash AS Ouda Progress in Nuclear Energy 134, 103681 , 2021 2021 Citations: 32
Effect of Superplasticizer Dosage on Compressive Strength and Microstructure of High Volume Basic-Oxygen Slag Mortar Exposed to Sea Water Attacks AS Ouda Journal of Civil Engineering and Construction 10 (1), 11-20 , 2021 2021 Citations: 2
Development the properties of brick geopolymer pastes using concrete waste incorporating dolomite aggregate AS Ouda, M Gharieb Journal of Building Engineering 27, 100919 , 2020 2020 Citations: 81
Effect of concrete waste on compressive strength and microstructure development of ceramic geopolymer pastes AS Ouda, KL Abdel-Aal Transactions of the Indian Ceramic Society 78 (3), 146-154 , 2019 2019 Citations: 18
Thermal resistance of alkali-activated metakaolin pastes containing nano-silica particles. AM Rashad, AS Ouda Journal of Thermal Analysis & Calorimetry 136 (2) , 2019 2019 Citations: 54
MOST CITED SCHOLAR PUBLICATIONS
Development of high-performance heavy density concrete using different aggregates for gamma-ray shielding AS Ouda Progress in Nuclear Energy 79, 48-55 , 2015 2015 Citations: 417
The effect of replacing sand by iron slag on physical, mechanical and radiological properties of cement mortar AS Ouda, HA Abdel-Gawwad HBRC journal 13 (3), 255-261 , 2017 2017 Citations: 89
Preparation and characterization of one-part non-Portland cement HAA Gawwad, S Abd El-Aleem, AS Ouda Ceramics International 42 (1), 220-228 , 2016 2016 Citations: 88
Development the properties of brick geopolymer pastes using concrete waste incorporating dolomite aggregate AS Ouda, M Gharieb Journal of Building Engineering 27, 100919 , 2020 2020 Citations: 81
Physico-mechanical properties of high performance concrete using different aggregates in presence of silica fume SA Abo-El-Enein, HA El-Sayed, AH Ali, YT Mohammed, HM Khater, ... HBRC Journal 10 (1), 43-48 , 2014 2014 Citations: 76
Behavior of alkali-activated metakaolin pastes blended with quartz powder exposed to seawater attack AM Rashad, AS Ouda, DM Sadek Journal of Materials in Civil Engineering 30 (8), 04018159 , 2018 2018 Citations: 56
Thermal resistance of alkali-activated metakaolin pastes containing nano-silica particles. AM Rashad, AS Ouda Journal of Thermal Analysis & Calorimetry 136 (2) , 2019 2019 Citations: 54
An investigation on alkali-activated fly ash pastes modified with quartz powder subjected to elevated temperatures AM Rashad, AS Ouda Construction and Building Materials 122, 417-425 , 2016 2016 Citations: 52
Assessing the physical, mechanical properties, and γ-ray attenuation of heavy density concrete for radiation shielding purposes AS Ouda, HS Abdelgader Geosystem Engineering 22 (2), 72-80 , 2019 2019 Citations: 47
Effect of tidal zone and seawater attack on high-volume fly ash pastes enhanced with metakaolin and quartz powder in the marine environment AM Rashad, AS Ouda Microporous and Mesoporous Materials 324, 111261 , 2021 2021 Citations: 40
Behavior of alkali-activated pozzocrete-fly ash paste modified with ceramic tile waste against elevated temperatures and seawater attacks AS Ouda, M Gharieb Construction and Building Materials 285, 122866 , 2021 2021 Citations: 39
A preliminary investigation on gamma-rayattenuation of alkali-activated concrete waste based-geopolymer modified with pozzocrete-fly ash AS Ouda Progress in Nuclear Energy 134, 103681 , 2021 2021 Citations: 32
Effect of concrete waste on compressive strength and microstructure development of ceramic geopolymer pastes AS Ouda, KL Abdel-Aal Transactions of the Indian Ceramic Society 78 (3), 146-154 , 2019 2019 Citations: 18
An investigation on the performance of lightweight mortar-based geopolymer containing high-volume LECA aggregate against high temperatures AS Ouda, AM Rashad Environmental Science and Pollution Research 29 (18), 26631-26647 , 2022 2022 Citations: 17
Hydration characteristics of limestone filled cement pastes AH Ali, AM Kandeel, AS Ouda Chemistry and Materials Research 5, 68-73 , 2013 2013 Citations: 16
Estimation of radiation properties of high-performance concrete for use in nuclear installations AS Ouda Journal of Materials in Civil Engineering 28 (11), 04016121 , 2016 2016 Citations: 15
Evaluating the role of feldspar on the resistivity of alkali-activated slag towards seawater attack AS Ouda, M Gharieb Environmental Science and Pollution Research 30 (1), 127-144 , 2023 2023 Citations: 8
Insights into the physico-mechanical characteristics and corrosion behavior of high-performance heavy density concrete used in the construction of electro-nuclear power facilities AS Ouda Construction and Building Materials 443, 137838 , 2024 2024 Citations: 7
Effect of high temperature on physical, mechanical and microstructure properties of alkali-activated slag pastes blended with ceramic waste material AS Ouda European Journal of Environmental and Civil Engineering 26 (10), 4827-4846 , 2022 2022 Citations: 7
Effect of ceramic tile waste addition on the performance of slag-based geopolymer upon exposure to marine conditions: Physico-mechanical characteristics, and shielding … AM Abdelmonem, A Azam, A Alruwaili, AS Ouda, M Abd Elrahman Sustainable Chemistry and Pharmacy 43, 101886 , 2025 2025 Citations: 6