摘要
Abstract
Digital image correlation (DIC) method is a novel non-contact full field optical method for the measurement of deformation of specimens. Compared to the conventional methods for the deformation measurement that usually involve sensors being directly in contact with the samples, the DIC method has some advantages of easy operation, large scale and high accuracy deformation measurement, and flexible selection of the analysis area, etc.. In addition, polymer latexes are widely used in cementitious materials to improve their toughness and impermeability. This paper was to apply the DIC method to investigate the mechanical properties of polymer modified mortar (PMM). The full stress-strain curves of PMMs at different polymer contents were obtained under a compressive load by the DIC method and the conventional contacting method. The results show that besides the full stress-strain curves, the DIC method provides the additional information on cracking and fracturing of the specimens, which is more advantageous than the contacting methods. Compared to the full stress-strain curves obtained by the DIC method and the contacting method, the strain provided by the DIC methods that represents the deformation of the selected intermediate testing area is generally lower than that measured by the contacting method at a given stress load, which stands for the deformation of the whole sample. This phenomenon is due to the constriction effect of the surroundings for the selected intermediate testing area. A greater polymer content reduces the constriction effect of the surrounding material to the intermediate part. The failure mode of polymer modified mortar changes from brittle failure to ductile failure when the polymer content increases. Moreover, the 1st crack strain, peak strain and fracture energy of polymer modified mortar increase with the increase of polymer content.At low polymer dosages (i.e., <5％), the Poisson ratio of polymer modified mortar increases with the increase of polymer content.关键词
数字图像相关法/聚合物改性砂浆/变形/力学性能Key words
Digital image correlation method/polymer modified mortar/deformation/mechanical property分类
建筑与水利
