Improvement of performance properties of bitumen and bitumineous mixtures by adding sugar beet molasses

As in Turkey, in many other countries the most prevalent and preferred type of superstructure is observed to be the flexible pavements. Due to the special properties of materials used in the flexible pavements, costs pertinent to both construction and maintenance are quite exorbitant. Owing to important, yet, costly investments, besides, because of the incessant growth in traffic volume, implementation of flexible pavements necessitates substantial funding. It is obvious that disposal of various waste products in the nature would yield major problems including environmental pollution. Thus, numerous studies in several different contexts have hitherto been conducted to address application of by-products or waste products that are produced during or as a result of diverse manufacturing processes. Wastes are being used to produce novel products or are applied as additives to the existing ones. Treatment of by-products and waste products not only reduces application of scarce natural resources, but also prevents accumulation of materials intended to dump, which in turn impedes environmental destruction. In recent years, for the sake of waste elimination, a tendency toward utilization of industrial waste in preparation of road layers has emerged. Being a by-product of sugar mills, molasses is a dark, viscous, water-soluble, and carbohydrate-rich substance obtained from either sugar beets or cane sugar. This by-product is being added to bitumen as an additive in order to improve its rheological properties. In the same direction, the ultimate resolution of this study is to enhance performance of bitumen and bituminous mixtures by adding two different additives of sugar beet molasses and mixture of molasses and boric-oxide (hailed as MEBSA). In the course of this study, different samples containing varied percentages of additives were prepared. For both molasses and MEBSA, samples were prepared by gradually increasing the percentage of additives in the bitumen as 1, 2, 3, 5, 7.5 and 10 percent. Experimentations on efficacy evaluation of the aforestated additives on the rheology of the bitumen were initiated by conducting viscosity tests, carried out by the Brookfield Viscometer. Ensuing identification of the optimum viscosity ratios, comparisons among the original bitumen and bituminous mixtures were carried out through exertion of penetration tests, softening point tests, ductility tests and performance related tests such as Marshall Stability and stripping resistance tests. Furthermore, efficiency of the noted additives throughout both preparation and application processes of bituminous hot mixtures have been investigated with regard to some additional criteria, viz., energy saving, short-term aging of bitumen, and their workability. Ultimately, cost analyses were carried out to compare unit-prices of both the molasses and MEBSA additives to that of Styrene Butadiene Styrene, and to assess their impact on price per ton of asphalt mixtures.