Shielding and strength tests of silica fume concrete

Computational AI Models for Investigating the Radiation Shielding Potential of High-Density Concrete

Concrete is an economical and efficient material for attenuating radiation. The potential of concrete in attenuating radiation is attributed to its density, which in turn depends on the mix design of concrete. This paper presents the findings of a study conducted to evaluate the radiation attenuation with varying water-cement ratio (w/c), thickness, density, and compressive strength of concrete. Three different types of concrete, i.e., normal concrete, barite, and magnetite containing concrete, were prepared to investigate this study. The radiation attenuation was calculated by studying the dose absorbed by the concrete and the linear attenuation coefficient. Additionally, artificial neural network (ANN) and gene expression programming (GEP) models were developed for predicting the radiation shielding capacity of concrete. A correlation coefficient (R), mean absolute error (MAE), and root mean square error (RMSE) were calculated as 0.999, 1.474 mGy, 2.154 mGy and 0.994, 5.07 mGy, 5.772 mGy for the training and validation sets of the ANN model, respectively. Similarly, for the GEP model, these values were recorded as 0.981, 13.17 mGy, and 20.20 mGy for the training set, whereas the validation data yielded R = 0.985, MAE = 12.2 mGy, and RMSE = 14.96 mGy. The statistical evaluation reflects that the developed models manifested close agreement between experimental and predicted results. In comparison, the ANN model surpassed the accuracy of the GEP models, yielding the highest R and the lowest MAE and RMSE. The parametric and sensitivity analysis revealed the thickness and density of concrete as the most influential parameters in contributing towards radiation shielding. The mathematical equation derived from the GEP models signifies its importance such that the equation can be easily used for future prediction of radiation shielding of high-density concrete.

Radiation Shielding Concrete with alternate constituents: An approach to address multiple hazards

Radiation Shielding Concrete (RSC) is a superior alternative to many conventional and modern shields against gamma and neutron radiation hazards. The present work is the first comprehensive review on utilization of alternate materials, emphasizing hazardous industrial byproducts, as constituents of RSC. Such usage enhances the performance, sustainability, and affordability of RSC. Added advantages are the immobilization of wastes and the conservation of natural resources for RSC. The review analyses incorporation of ferrous and non-ferrous slags, mines wastes, plastics, red mud, cathode ray tube's glass, metallic wastes, fly ash, silica fume, and miscellaneous residues. Besides, utilization of fibers, nanoparticles, and calcined clay is investigated. The influence on shielding efficiency is adjudged by scrutinizing changes in parameters such as half-value layer and linear attenuation coefficients. Similarly, variations in mechanical and durability properties are investigated and compared. The underlying responsible factors related to the physical, chemical and morphological characteristics of materials and their consequences on RSC's behavior are correlated. In association with alternatives, the advantages, disadvantages, and possible treatment methods are discussed. The country-wise, material-specific, and progressive research trends are revealed to facilitate future work in this upcoming field. Finally, conclusions are drawn with exposition of current bottlenecks and scope of future research.

Properties of Cement-Based Composites Modified with Magnetite Nanoparticles: A Review

Despite the many available studies on the evaluation of the influence of nanomaterials on the properties of cement-based composites, the effects of some nanoparticles have not yet been fully recognized. Among the unrecognized nanomaterials are magnetite nanoparticles (MN). The literature devoted to this subject is limited. This paper reviews state-of-the-art research carried out on the effect of MN on the properties of cement-based composites. Detailed descriptions of the processing, microstructures (hydration products), properties (hydration, workability, mechanical and functional properties, and durability), and probability applications of MN-engineered cementitious composites are presented. Particular attention has been paid to MN application methods to the cement composite. Finally, the risks, challenges, and future development of MN-modified cement-based composites is discussed.