DESIGN OF BITUMINOUS MIXES FOR HEAVILY TRAFFICKED ROADS – A BOON TO INDIAN ROADS

Abstract

Abstract-A large number of road construction projects are currently under design and construction stage in India. If these projects are constructed with high modulus bituminous mixes then there will be a huge amount of savings in materials, reduced maintenance cost and increased service life of the pavement. High modulus bituminous mixes can be produced by using hard grade bitumen. The present experimental study aims at production of hard grade bitumen with PPA as modifier for the preparation of high modulus bituminous mixes. Bituminous mixes were prepared with Dense Bituminous Macadam (D.B.M) gradation for both conventional and laboratory produced hard grade bitumen. The tests conducted on prepared mixes were Marshall stability, Indirect tensile strength (ITS) and Resilient modulus (Mr). From the test results the optimum binder content was found as 5.27 % and 5.46 % for virgin and hard grade bituminous mixes. The marshall stability and ITS of mixes prepared with hard grade bitumen was found as 1.14 and 1.32 times higher than the virgin bituminous mixes. Resilient modulus at 35 o C found as 3310 MPa for mix prepared with hard grade bitumen and 1746 MPa for the virgin mix. Further, a pavement section was designed for 300 msa as per IRC: 37-2018 guidelines by using IIT Pave. After conducting several trials in IIT Pave the thickness of the base course is decreased by 40 mm by considering the bituminous mix prepared with hard grade bitumen. KeywordsHard grade bitumen, High modulus mix, Marshall stability and Resilient modulus.