Research Information System
Journal of Engineering Research (Kuwait), vol.11, no.3, pp.1-10, 2023 (SCI-Expanded, Scopus)
Asphalt recycling efforts are increasing in an effort to reduce the effects of high energy and raw material consumption in the asphalt sector. One of the most common methods for using old asphalt materials that still retain some value is recycling with foam bitumen. In practice, to prepare and evaluate cold mixes produced using foam bitumen, the indirect tensile strength (ITS) and resilient modulus (MR) methods are generally used. Among these methods, the ITS is mostly applied for the evaluation of the optimum percentages of materials, and the MR is used to evaluate the mixture performance. In these experiments, for cold mixes prepared with foam bitumen, the optimum foam bitumen values of the production series were first determined using ITS tests. Then, reproductions were created with these optimum values, and the MR values were determined. It was found that the ITS and MR values were significantly affected by the material gradation and showed the opposite trends for materials with the same gradation. The effect of the type of active filler was the same as the values of the mixtures on the ITS and MR. In particular, the MR results were affected by the bitumen grade. Based on the results of this study, evaluation limit values of 225 kPa for ITSDRY, 150 kPa for ITSWET, 70% for TSR, 400 MPa for MR, and 0.21 for the layer coefficient are recommended for foam bitumen stabilized material (FBSM).