Resistivity measurement of conductive asphalt concrete based on two-electrode method

The objective of this work is to develop a novel methodology for determining real resistivity of conductive asphalt concrete based on two-electrode method. Due to an influence of contact resistance, the measured resistivity is always not equal to the real resistivity. To determine the real resistivity, a linear relationship of the measured resistivity, contact resistance and the real resistivity was established. Then experiments for six specimens with varying graphite contents were designed and performed to validate the formulation. Results of experiments demonstrate that the slope of the line represents contact resistance, and the intercept indicates the real resistivity. The effects of graphite content on contact resistance and real resistivity are also revealed. Finally, results show that the influence of contact resistance on accuracy of resisitvity measurement becomes more serious if graphite content is beyond 3%. Hence, it is the time to choose this novel methodology to determine the real resistivity of asphalt concrete by taking account of contact resistance.