Toughness improvement of epoxy resin mortar by incorporation of ground calcium carbonate

• The impact toughness of ERM had greatly improved with GCC addition.
• GCC induced lots of crazes and triggered extensive plastic deformation in ERM.
• The interface boundary between epoxy matrix and fillers (sand and GCC) was perfect.
• The high-performance repair mortar is obtained through orthogonal experiment.

In this paper, ground calcium carbonate (GCC) was selected to improve the properties of epoxy resin mortar (ERM). The results indicated that the flexural strength and ratio of flexural strength to compressive strength of ERM got great increase by incorporation of GCC. At the same time, the impact toughness of ERM had greatly improved with GCC. To some extent, it increased with increasing addition of GCC. Scanning electron microscope (SEM) analysis illustrated the toughening mechanism of ERM filled with GCC. Through orthogonal experiment, the optimal combinations of the process parameters for a high-performance repair mortar are obtained.