Thermomechanical Properties of Epoxy Mortars

Three epoxy mortar materials are subjected to failure tests in compression and split‐cylinder tension over a temperature range of −35°–200°F. The tests are completed using 76.22‐mm‐ (3‐in.) diameter, 152.4‐mm‐ (6‐in.‐)long cylinders and failed specimens are examined using a microscope. Axial and radial strains are measured during the compressive tests to determine the compressive modulus and Poisson's ratio. All three mortar materials exhibit an apparent linear relationship between ultimate compressive strength and temperature. The split‐cylinder tensile test results show that tensile strength varies linearly with temperature at temperatures below the glass transition region. The compressive modulus is found to increase with decreasing temperatures. The mode of failure also varies with temperature, and microscopic examination of fracture surfaces reveals that fracture occurs at the epoxy‐aggregate interface and within the epoxy itself. Brittle failure specimens show the formation of a powdery residue on the fracture face. The testing and examination suggests that temperature has a significant effect on the ultimate strength and behavior of epoxy mortars.