Assessment of Strength Characteristics of Bituminous Concrete Modified using HDPE

Abstract

Bituminous Concrete is composite material made by mixing aggregates and bitumen in fixed proportions used for construction of bituminous pavements. Bituminous pavements transfer wheel loads to subgrade by grain to grain transfer mechanism, to transfer loads by this mechanism the bituminous concrete should have high strength. To overcome the problems posed by increased traffic load and deteriorated environmental conditions different types of modifiers are being used in bituminous concrete. Modification of bituminous concrete is done to increase its stability and improve other characteristics. HDPE is one modifier which have been used and being used in bituminous construction. Bituminous concrete modified using HDPE is formed by mixing HDPE in bituminous concrete. In the present study HDPE is used as modifiers for bitumen as well as for bituminous concrete. HDPE were added to bitumen and physical properties of modified bitumen were assessed by conducting penetration value test, ductility value test, softening point, flash & fire point tests on bitumen modified using HDPE. After assessing the physical properties of modified bitumen cylindrical moulds were casted using BC modified by using HDPE, the amount of HDPE was varied from 8% to 10% by the weight of bitumen. Marshall Test was performed on the cylindrical moulds to find stability value and flow value of bituminous concrete modified using HDPE. Results of study revealed that, ductility value and penetration value of bitumen decreased with increment of HDPE content while softening point, Flash & Fire point increased with increment in HDPE content. When HDPE were used in BC and checked for Marshall Stability values, stability increased first reached maximum and then started decreasing. The maximum stability value was obtained for 9% content of HDPE by the weight of bitumen. Economic usage of HDPE in BC was evaluated for 1Km, 7m lane width and 50mm thickness of bituminous concrete pavement. Therefore, use of HDPE in bituminous concrete provides a viable solution for the disposal of waste HDPE, this factor alone makes use of HDPE in bituminous concrete very acceptable and admirable