Valorization of hazardous chrysotile by H3BO3 incorporation to produce an innovative eco-friendly radiation shielding concrete: Implications on physico-mechanical, hydration, microstructural, and shielding properties

Masoud, M.A.; El-Khayatt, A.M.; Mahmoud, K.A.; Rashad, Alaa M.; Shahien, Mohamed G.; Bakhit, Bottros R.; Zayed, Ahmed M.

doi:10.1016/j.cemconcomp.2023.105120

Cited by 21 publications

(3 citation statements)

References 132 publications

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“…The above-mentioned results were in agreement with the outcomes of the macromechanical tests, and the addition of excessive fly ash and red mud was rather detrimental to the subsequent development of the interfacial bond strength between the GPM and the concrete substrate. The categories of hydration gel products in the cement mortar in Figure 8d are mainly C-S-H and C-A-H, which were in accordance with the results of previous investigations [52][53][54] on the subject and will not be discussed in detail here.…”

Section: Xrd Analysissupporting

confidence: 89%

“…In order to elucidate the mechanism of chemical interaction between GPM and concrete substrate, the microstructural characteristics of the interfacial transition zone (ITZ) were determined by carrying out an SEM test with reference to previous research reports [52][53][54] on the one hand, and XRD test was undertaken to investigate the mineral crystalline phase composition of GPM to determine the main source of the interfacial bond strength between GPM and concrete substrate on the other hand. The ITZ core fragments and GPM fragments were collected at the end of the double-sided shear test, sealed in anhydrous ethanol for 24 h to terminate the hydration behavior of the silica-aluminate material, and then dried in a desiccator at low temperature to a constant weight.…”

Section: Characterization Methodsmentioning

confidence: 99%

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Interfacial Behavior of Slag, Fly Ash, and Red Mud-Based Geopolymer Mortar with Concrete Substrate: Mechanical Properties and Microstructure

Long,

Zhao,

Zhang

et al. 2024

Buildings

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Geopolymer, as a new type of solid waste-based inorganic cementitious material, exhibits outstanding behavior in terms of physical and chemical performance, macromechanical properties, long-lasting stability, and features potential application development tendency in the field of repair and reinforcement of existing concrete structures. This paper investigated the interfacial behavior of geopolymer mortar with OPC concrete substrate under different slag, fly ash and red mud mixing proportions, while cement mortar was used as a control group for the research. The interfacial bonding properties of the geopolymer mortar to the OPC concrete substrate were elaborated by carrying out split tensile test, double-sided shear test, and three-point bending test. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed to further analyze the microstructural characteristics and physical phase components of the interfacial transition zone between the geopolymer mortar and the OPC concrete substrate. The results indicated that the compressive strength of slag-fly ash-red mud-based geopolymer mortar under different mixing ratio conditions was consistently superior to that of cement mortar, where the optimum mixing ratio for the geopolymer mortar was S33F33R33. Overall, the interfacial bonding properties of the geopolymer mortar to the OPC concrete substrate gradually increased with the increment of the slag content, however, an evolutionary trend of minor enhancement followed by a gradual reduction was observed with the growth of the fly ash and red mud content.

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Section: Xrd Analysissupporting

confidence: 89%

Section: Characterization Methodsmentioning

confidence: 99%

Interfacial Behavior of Slag, Fly Ash, and Red Mud-Based Geopolymer Mortar with Concrete Substrate: Mechanical Properties and Microstructure

Long,

Zhao,

Zhang

et al. 2024

Buildings

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“…Due to the fast rise in the world's population as well as the gradual degradation of the world's infrastructure, there is an urgent requirement for the quick development of the construction sector. Ordinary Portland Cement (OPC) is a binder used frequently in concrete, one of the most common construction materials [1][2][3][4][5][6]. Using OPC-based concrete presents several environmental challenges, the most significant of which is the substantial quantity of cement that is required, which in turn results in an enormous amount of carbon dioxide (CO 2 ) emissions.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Framework for Geopolymer Gels Construction: An Optimized LSTM Technique to Predict Compressive Strength of Fly Ash-Based Geopolymer Gels Concrete

Shi,

Chen,

Wang

et al. 2024

Gels

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As an environmentally responsible alternative to conventional concrete, geopolymer concrete recycles previously used resources to prepare the cementitious component of the product. The challenging issue with employing geopolymer concrete in the building business is the absence of a standard mix design. According to the chemical composition of its components, this work proposes a thorough system or framework for estimating the compressive strength of fly ash-based geopolymer concrete (FAGC). It could be possible to construct a system for predicting the compressive strength of FAGC using soft computing methods, thereby avoiding the requirement for time-consuming and expensive experimental tests. A complete database of 162 compressive strength datasets was gathered from the research papers that were published between the years 2000 and 2020 and prepared to develop proposed models. To address the relationships between inputs and output variables, long short-term memory networks were deployed. Notably, the proposed model was examined using several soft computing methods. The modeling process incorporated 17 variables that affect the CSFAG, such as percentage of SiO2 (SiO2), percentage of Na2O (Na2O), percentage of CaO (CaO), percentage of Al2O3 (Al2O3), percentage of Fe2O3 (Fe2O3), fly ash (FA), coarse aggregate (CAgg), fine aggregate (FAgg), Sodium Hydroxide solution (SH), Sodium Silicate solution (SS), extra water (EW), superplasticizer (SP), SH concentration, percentage of SiO2 in SS, percentage of Na2O in SS, curing time, curing temperature that the proposed model was examined to several soft computing methods such as multi-layer perception neural network (MLPNN), Bayesian regularized neural network (BRNN), generalized feed-forward neural networks (GFNN), support vector regression (SVR), decision tree (DT), random forest (RF), and LSTM. Three main innovations of this study are using the LSTM model for predicting FAGC, optimizing the LSTM model by a new evolutionary algorithm called the marine predators algorithm (MPA), and considering the six new inputs in the modeling process, such as aggregate to total mass ratio, fine aggregate to total aggregate mass ratio, FASiO2:Al2O3 molar ratio, FA SiO2:Fe2O3 molar ratio, AA Na2O:SiO2 molar ratio, and the sum of SiO2, Al2O3, and Fe2O3 percent in FA. The performance capacity of LSTM-MPA was evaluated with other artificial intelligence models. The results indicate that the R2 and RMSE values for the proposed LSTM-MPA model were as follows: MLPNN (R2 = 0.896, RMSE = 3.745), BRNN (R2 = 0.931, RMSE = 2.785), GFFNN (R2 = 0.926, RMSE = 2.926), SVR-L (R2 = 0.921, RMSE = 3.017), SVR-P (R2 = 0.920, RMSE = 3.291), SVR-S (R2 = 0.934, RMSE = 2.823), SVR-RBF (R2 = 0.916, RMSE = 3.114), DT (R2 = 0.934, RMSE = 2.711), RF (R2 = 0.938, RMSE = 2.892), LSTM (R2 = 0.9725, RMSE = 1.7816), LSTM-MPA (R2 = 0.9940, RMSE = 0.8332), and LSTM-PSO (R2 = 0.9804, RMSE = 1.5221). Therefore, the proposed LSTM-MPA model can be employed as a reliable and accurate model for predicting CSFAG. Noteworthy, the results demonstrated the significance and influence of fly ash and sodium silicate solution chemical compositions on the compressive strength of FAGC. These variables could adequately present variations in the best mix designs discovered in earlier investigations. The suggested approach may also save time and money by accurately estimating the compressive strength of FAGC with low calcium content.

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Evaluation of Some Heavyweight Minerals as Sustainable Neutron and Gamma-Ray Attenuating Materials: Comprehensive Theoretical and Simulation Investigations

Zayed,

El-Khayatt,

Mahmoud

et al. 2024

Arab J Sci Eng

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This study comprehensively evaluates the radiation attenuation efficiencies of hematite and barite, commonly used materials in radiation shielding, using theoretical and simulation investigations. The MCNP-5 code was used to obtain the linear attenuation coefficient (LAC) within the energy range of 0.015–15 MeV, with validation by the XCOM program. Based on these LAC values, various gamma-ray shielding parameters were determined: mass attenuation coefficient, half-value layer, radiation protection capacity, mean free path, transmission factor, and equivalent thickness to lead (ETPb). Additionally, effective atomic number (Zeff) and electron density (Neff) were calculated, including both single-energy and energy-dependent forms for photon absorption and interaction. Furthermore, MCNP-5 simulations and NGCal program calculations were used to assess thermal neutron attenuation, while the NXcom program determined fast neutron behavior. This analysis revealed superior γ-ray shielding for barite compared to hematite. Similarly, the NXcom program indicated better fast neutron shielding for barite. However, interestingly, simulations validated a 210% higher effectiveness in thermal neutron attenuation for hematite. Finally, comparing the studied materials with other shielding materials demonstrated promising potential as environmentally friendly alternatives for effective shielding against various radiation types.

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Valorization of hazardous chrysotile by H3BO3 incorporation to produce an innovative eco-friendly radiation shielding concrete: Implications on physico-mechanical, hydration, microstructural, and shielding properties

Cited by 21 publications

References 132 publications

Interfacial Behavior of Slag, Fly Ash, and Red Mud-Based Geopolymer Mortar with Concrete Substrate: Mechanical Properties and Microstructure

Interfacial Behavior of Slag, Fly Ash, and Red Mud-Based Geopolymer Mortar with Concrete Substrate: Mechanical Properties and Microstructure

Mechanical Framework for Geopolymer Gels Construction: An Optimized LSTM Technique to Predict Compressive Strength of Fly Ash-Based Geopolymer Gels Concrete

Evaluation of Some Heavyweight Minerals as Sustainable Neutron and Gamma-Ray Attenuating Materials: Comprehensive Theoretical and Simulation Investigations

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