Influence of the multifractal characteristics of a macrostructure on cement mortar strength.

The multiparametricity of the production technology of mortar determines its complex structure. The multifractal analysis of a plasticized cement mortar macrostructure was carried out. By analyzing statistical dimensions of the multifractal Renyi spectrum, it was found that the mortar macrostructure has inhomogeneous areas with a predominance of sand or cement stone. Models for predicting bending strength are obtained with a regression analysis of the statistical dimensions values. A relatively high correlation of R² = 0.75 and R² = 0.81 among the models under consideration is observed between the fractal dimensions D₀ of sand sites and pores. Also, a correlation with strength for the dimension of the structure light sections with sand D₁₀₀ (R² = 0.77) and the structure dark sections with a predominance of cement stone D_-100 (R² = 0.66) was established. The sensitivity coefficient between these characteristics was determined to assess the degree of influence of the spectrum of dimensions on bending strength. According to the sensitivity values, the dimensions were ranked to the determining parameter (strength): 1). 0.76 for D_o of pores, 2). 0.61 for D₁₀₀ of sand, 3). 0.60 for D_-100 of cement stone, 4). 0.59 for D_o of sand, 5). 0.44 for Do of cement stone, 6). 0.41 for D1 of cement stone, 7). 0.40 for D₂ of cement stone. Establishing the sensitivity between the dimensions of elements of the mortar structure and the criteria of its quality gives the opportunity to filter out the experiment results, which do not allow us to predict the determining parameter with accuracy acceptable for practical purposes. [ABSTRACT FROM AUTHOR]