RUTTING PARAMETERS OF MODIFIED ASPHALT BINDER WITH MICRO AND NANO-SIZE OF METAKAOLIN POWDER

This research studies the feasibility of using micro and Nano-size of Metakaolin powder to develop the characteristics of the asphalt binder by three contents (1 %, 3 %, and 5%) of asphalt weight with high shear mixer for a 60 min.set at 4000 rpm to prepare a homogeneous composite. Rheological properties were studied by the rotational viscosity value, penetration test, softening point temperature, penetration index, and ductility test. Rutting characteristics were determined also by the dynamic shear rheometer test on the control and the modified binder. Overall, the addition of Metakaolin has a helpful influence on the rheological properties of the modified asphalt binder. The greater percentages of improve the viscosity and softening point values at 6 % content of Nano (nMK) and micro (mMK) of Metakaolin were about (77, 40) % and (14, 9) %, respectively. Besides greater percentages of decrease in ductility and penetration values at 6 % content of Nano (nMK) and micro (mMK) of Metakaolin were approximately (18, 11) % and (30,16) %, respectively. Also, the complex shear modulus values increased and phase angle value reduced, attributable to the addition the micro (mMK) and Nano (nMK) of Metakaolin contents. The greater value of the complex shear modulus was detected at 5 % of the micro and Nano size of Metakaolin content. Furthermore, the results exhibited the greater values of complex shear modulus were at PG 76, PG 64 and PG 58 for types of Nano Metakaolin, micro Metakaolin, and control asphalt binder, respectively. It is an indication of improves the rutting performance as well as become appropriate for building the flexible pavements of the highways in hot weather circumstances.