Journal of the Korean Asphalt Institute ISSN:2234-0785(Print) 2635-9553(Online) 한국아스팔트학회지

The area (A), from the origin to peak point under a curve, which was fit to the test data points of load (P) and deformation (p) for many strength tests on asphalt concrete, is used for assesment of the pseudo fi'acture toughness (PFT). The curves the indirect tensile strength (ITS) test and the deformation strength (SD) are relatively well fit to the regression curve of the 2nd degree polynomial. However, the data obtained from the flexural strength (FS) test of the beam under various temperature conditions show various types of curves. Since the exact computations of the PFT for those data were not easy, it was intended to develop a simple model for PFT calculation of the data which were well fit to the 2nd degree polynomial. It was also shown in this study that other types of data which were obtained from FS test at various temperatures should be fitted to the higher degree of polynomials. The simple model for the data, which were well fit to the 2nd degree polynomial, was developed as FT = 2Pu/39 in which P is the peak load (N) and u is the deflection (mm) at the P. It was found that the other data points from FS tests were well fit to the regression curves of 3rd, 4th, 5th or 6th polynomials with R2 > 0.99. Therefore, the Area by the integration firam 0 to D using the regression curve, which showed the nearest P value of test data P at was found to be a better assesment of PFT.