Evaluation of Marshall mix design of bituminous mixtures prepared with clinoptilolite

Abstract

Today, the production of asphalt has increased with the increase in demand for highway network. However, due to harmful effects of asphalt production on the nature, researchers have tried to explore new kinds of asphalt that are environmentally-conscious, cost lower production and that exhibit at least the same performance of conventional ASPHALT in terms of properties. The main objective of using warm mix asphalt (WMA) is to reduce emissions and improve the workability by lowering the mixing and compaction temperatures of ASPHALT through different mechanisms. Recent advances in WMA have spurred interests in the use of organic commercial waxes such as Sasobit (R), Asphaltan B (R) as well as synthetic zeolite such as Advera (R) WMA and Aspha-min (R) as additives in bitumen to achieve certain positive effects. There are over 50 billion tons of high quality natural zeolite reserves in Turkey. This means that natural zeolite can be utilized in the production of warm mix asphalt. This study targets the evaluation of clinoptilolite type natural zeolite as a warm mix additive. The bitumen samples have been produced by mixing 50/70 penetration grade base bitumen with clinoptilolite at five different contents. After determining the production temperature and time related to each sample, the properties have been evaluated by conventional bitumen tests. The impact of the reduction of mixing and compaction temperatures on the mechanical behavior of asphalt concrete samples involving clinoptilolite has also been determined and compared with the control samples.