Interlacing the Evalation of Mechanical Properties of Concrete with Near-Infrared Spectroscopy and X-Ray Diffraction Using Multivariate Data Analysis.
Accurate evaluation of the compression strength of concrete is critical in the construction industry. It is the most common measure used by civil engineers to design and evaluate the material's structural performance. Naturally, greater accuracy is achieved by destructive tests. The objective of this research is to predict the said compression strength indirectly through near infrared spectroscopy (NIRS) and x-ray diffraction through a multivariate data analysis strategy. Thus, a novel non-destructive methodology will result. In preliminary studies, NIRS analysis of concrete samples allowed tracking the variation of the water band at early age of mature concrete. The x-ray diffraction spectra permitted to correlate the spectral variation with the compression strength of concrete at mature ages. Principal component analysis (PCA) and least squares (PLS) models were developed for qualitatively and quantitatively analysis, respectively.