Simulating chloride penetration in fly ash concrete by a fractal derivative model

Abstract

In the real engineering field, the chloride ions behave abnormal diffusion phenomena in concrete caused by different compositions of the concrete which lead to the complex physical and chemical properties. This paper utilizes a fractal derivative model and a fractional derivative model to describe the diffusion phenomena. Furthermore, according to actual experimental data in the field, the fractional and fractal model can simulate the diffusion behavior of chloride ions in concrete. In comparison to the fractional derivative model, the fractal derivative model gives a simpler mathematical expression and lower calculation costs. In addition, the linear regression analysis method is used to establish an effective relationship between the internal composition of concrete and the parameters of fractal model such as fractal order, α, and diffusion coefficient, D. As a result, the fractal model with the parameters estimated by previous relationship can predict the diffusion behavior of chloride ions.

Fractal Analysis of Cement-Based Composite Microstructure and Its Application in Evaluation of Macroscopic Performance of Cement-Based Composites: A Review

“…Cement-based composites (CCs) are the most widely used building materials nowadays, which play an indispensable role in engineering constructions such as roads, bridges, tunnels, and hydraulic projects [1]. The application of CCs largely depends on their macroscopic properties, including mechanical properties [2,3], impermeability [4,5], frost resistance [6][7][8], corrosion resistance [9][10][11], and high-temperature resistance [12][13][14]. These macroscopic properties are often closely related to the microscopic structure.…”

Shape reconstructions and morphing kinematics of an eagle during perching manoeuvres*

“…It is studied and extracted to reconstruct the bionic blades with improved aerodynamic performances by Qu and Liu. [21] It is impressive that the perching of steppe eagle Haliaeetus Albicilla was studied. [22] The aeroelastic deflections of the covert feathers of an eagle were investigated using onboard and high-speed digital video during wide-ranging free flight.…”