Using interpolation and correlation to evaluate the quality of cement composites exposed to a thermally aggressive environment

Introduction. The article addresses the quality evaluation of cement composites after their exposure to the atmospheric environment that features a rapid change in positive and negative temperatures. The article has a numerical assessment of the quality of cement composites. The quality assessment method encompasses the Spearman’s rank correlation, the coefficient of determination, and the adjustment ratio. Materials and methods. Testable cement composites are the compositions numbered from one to eight. They differ in the concentration of various additives, including superplasticizers and aggregates. Testable compositions were exposed to cyclic changes in positive and negative temperatures, and four of their properties were checked in the points of control on Day 0, Day 15, and Day 45. Linear interpolation was used to expand the data array. Changes in the properties of composites were compared with the benchmark values; the Spearman’s rank correlation and the coefficient of determination were calculated. Moreover, arrays of interpolated values were reduced to relative units to calculate the adjustment ratios. Entry values were employed to develop the evaluation metrics and assess the quality of cement composites. Results. The proposed numerical metrics is used to rank the testable samples and identify the best compositions. Library functions and transformations, available in the MATLAB system, are applied to each action, which can be implemented in nearly any software programming language. Conclusions. The proposed method of heuristic quality evaluation of cement composites may be applied to the cases when testable samples are exposed to versatile adverse and aggressive operating conditions.