Engineering and microscopic characteristics of natural rubber latex modified binders incorporating silane additive

Asphalt pavement structures in countries with tropical climates are prone to experience distress, mainly due to water related damage. This study aims to evaluate the effects of ZycoTherm on the behaviour of natural rubber latex (NRL) modified asphalt binders. The morphology of the modified asphalt binders was also investigated. Two different percentages of NRL were incorporated in this study, at 3% and 6% respectively based on the weight of the asphalt binder. The modified asphalt binders (with or without ZycoTherm) were analysed based on softening point, penetration value, rotational viscosity, complex modulus, phase angle, rutting potential, and torsional recovery (T-R). Subsequently, the spreadability of NRL in the asphalt binder was observed using a polarising optical microscope. The results indicate that the addition of NRL improved the performance of the asphalt binder in terms of its G*/sin delta parameter. An agglomerated network of mixed microstructures was formed in the modified asphalt binder matrix irrespective of the aging condition. Meanwhile, the morphology structure of virgin and short term-aged binders prepared with ZycoTherm indicates uniform dispersed network monographs. From the modified asphalt binder test results, it can be deduced that asphalt binders prepared with ZycoTherm exhibit superior resistance towards rutting potential.