Non-Destructive Evaluation of Cement Mortar Quality with Hyperspectral Remote Sensing Methods

Abstract. Cement mortar is a fundamental material in construction, with its strength and durability influenced by mix proportions and curing conditions. This study investigates the spectral characteristics and compressive strength of cement mortar mixes with varying cement-to-sand ratios (1:3, 1:4, and 1:6) over curing periods of 7 and 14 days. Utilising an SVC HR-1024i field spectroradiometer, spectral reflectance measurements were conducted to assess the surface properties of mortar cubes, while compressive strength tests were performed using a Universal Testing Machine. Results demonstrate a strong correlation between mix composition, curing duration, and both reflectance and strength developed with time. Higher cement content resulted in increased compressive strength and reflectance, particularly on the top surfaces of the samples. Further, spectral reflectance values increased with curing time. It may indicate the influence of hydration and microstructural densification on surface characteristics. Overall, this research introduces spectral analysis as a non-destructive method for evaluating mortar quality. It also offers a practical alternative to hectic and time-consuming traditional strength testing approaches. By highlighting the significant differences in reflectance based on mix proportions and curing conditions, the findings can contribute to improved quality control in construction materials. It can promote further exploration of non-destructive testing methodologies in this field.