Mechanical Properties of Warm Mix Asphalt–Stone Matrix Asphalt Modified with Nano Zeolite Material

ABSTRACT The purpose of this article is to present an experimental study to characterize the mechanical performance of modified warm mix asphalt mixtures with synthetic zeolite in nano and granule form. The effects of 0.1, 0.2, and 0.3 % of zeolite in nanocrystal powder and granule form have been evaluated by conducting indirect tensile strength (ITS) for conditioned and unconditioned specimens and wheel track tests. The tensile strength (TS), compressive stress at failure (CSF), equivalent modulus, toughness index, and moisture susceptibility (tensile strength ratio [TSR]) parameters have been calculated by ITS test. Also, rutting depth has been calculated by the wheel track test. According to the results, using zeolite material in nanocrystal powder and granule form has a similar effect on decreasing the TSR content and increasing the moisture susceptibility. Moreover, zeolite decreased the rutting depth, and because of the results, it should be noted that nanocrystal powder material reduced the rutting depth by about 40 % more than granule form. Furthermore, zeolite caused an increase in all the parameters obtained from the ITS test about 21–70 %. Overall, the results show that zeolite had a good effect on the physical properties of the mixture; however, zeolite in granule form caused a reduction in TS (dry condition) and CSF (wet condition).