Evaluation of modified bituminous mix parameters by adding plastic waste and Crumb-rubber waste

Abstract

These days, pavements are subjected to a wide range of loading conditions that affect the pavement's performance, resulting in a broad range of distresses. Innovating technologies such as the incorporation of waste plastic and waste tire rubber in the design of pavement have not only increased the strength of the road, but they have also increased the life of the roads. This study investigated the composite effects of waste plastic and crumb rubber (CR) as bitumen modifiers in improving the properties of flexible pavement. Various tests were carried out on aggregates, bitumen, and bituminous mixes as part of this investigation. Since Asphalt is visco-elastic in nature, change in the temperature and different loading condition has a substantial outcome on functioning of asphalt. Comparative study of conventional bituminous mix and modified bituminous mixes with replacement of crumb rubber for fine aggregate in varying percentages like 5%, 10% and 15% and raw coarse aggregate is completely replaced with LDPE coated aggregate at standard mixing and compaction temperature. Coarse aggregate is coated with LDPE in varying percentages like 5%, 7% and 10% and the physical properties like crushing, impact and abrasion values of plastic-coated aggregate is compared with the conventional aggregate. Bitumen binder of VG – 30 with aggregate coated with LDPE and CR shows significant enhanced results in stability, flow value, air voids and specific gravity. Various physical tests on bitumen binder such as Penetration, Viscosity, softening point, loss on heating, Ductility and Flash and Fire point test, were conducted. The bituminous mix using CR is as per the procedure of dry mixing. The optimum percentage of binder content was calculated based on the results of all these tests, which had produced acceptable results in all of the tests conducted. That optimum percentage binder was used in the preparation of bituminous mixes in the testing of pavement properties such as Compressive strength, Marshall Stability and indirect tensile strength. According to the test results, bitumen containing 10% replacement of crumb rubber outperforms conventional bitumen in terms of load-bearing capacity, while aggregates containing approximately 10% plastic coating outperform conventional aggregates. When compared to conventional mixes, it is discovered that the strength has been increased by 60%.