The modulus of elasticity, resistivity and capacitive reactance were determined for carbon nanotube reinforced mortars, near percolation. It is shown that the abrupt decrease of the resistivity values observed at the CNT content of 0.1 wt% is associated with the onset of percolation. Mortars reinforced with 0.1 wt% CNTs exhibit an 89% increase in Young's modulus. Values of resistivity and capacitance are 27% and 90% lower than that of the plain mortar, respectively. After the conductive network is formed, resistivity values show a little dependence on the CNT content, reaching a plateau. Capacitance on the other hand was increased by an order of magnitude, showing an amplified energy storage ability, probably due to the existence of small CNT agglomerates. The observed relationship between capacitance values and modulus of elasticity may provide valuable information on the actual CNT dispersion state in the matrix.