AN INVESTIGATION ON THE EFFECT OF HIGH TEMPERATURES ON MECHANICAL PROPERTIES AND MICROSTRUCTURE OF CONCRETE CONTAINING MULTI-WALLED CARBON NANOTUBES

In this paper, the eect of multi-walled carbon nanotubes on the properties of concrete was evaluated in the post-heat treated condition. Following this, a number of cylindrical specimens (10 x 20 cm) including multiwalled carbon nanotubes in dierent percentages of 0.5, 1 and 1.5% by weight of cement were cast. Later on, concrete specimens in the electric furnace were exposed to temperatures of 25, 100, 250,500 and 7000C and after cooling down, compressive and tensile strength tests were carried out on them. The results showed that by increasing multi-walled carbon nanotubes in concrete, compressive and tensile strengths of concrete were increased up to 138% and 88%, respectively. In addition, dissipation of energy and modulus of elasticity of concrete specimens were up to 2 times more than that of control concrete specimens. The SEM test results indicated that a strong bond between concrete particles exists at the room temperature and upper than that.