Paper Title
Digital Image Analysis for Assessment of Contact Angles and Stiffness of Fiber Reinforcement

Abstract
Accurate assessment of fibers used as reinforcement of cementitious composites is quite demanding. Conventional techniques often lack the required accuracy and the measurement and analysis of results can be rather laborious. To eliminate these drawbacks a user-friendly software has been developed to (i) automatically evaluate the contact angle of fibers partially submerged in fluid, and to (ii) analyze the elongation of fibers during tensile and pull-out tests. The first procedure exploits the binarization of images, identification of contours, and calculation of tangents. The latter is based on digital image correlation (DIC) and tracking of pixel subset displacements. The results demonstrate that both of these methods are capable of providing valuable and accurate information with relatively low computational cost and labor of a human operator. Keywords- Contact Angle Measurement, Digital Image Correlation, Image Analysis, Displacement Measurement, Fiber Reinforcement.