USE OF CRUMB RUBBER IN FLEXIBLE PAVEMENTS

Abstract

In the modern era, nationwide connectivity is a precondition for the economic and social development. In Bangladesh, flexible pavements count about 98% of paved roads. But these conventional bituminous pavements are highly susceptible to moisture damage, temperature variation and need routine maintenance. So, conventional bitumen modification is a crying need. Bangladesh generates about 90000 tons of non-biodegradable waste tires annually which creates a huge environmental problem. But this waste tires can effectively be incorporated with neat bitumen to make bituminous roads durable, less susceptible to temperature variation and highly resistant to moisture induced damage. Marshall mix design method was used to evaluate the performance of neat bitumen and crumb rubber modified bitumen (CRMB) mixtures whether they meet mix design requirements or not. Water sensitivity analysis was done for both bituminous sample. Loss of stability due to waterlogging was investigated by retained stability test. Resistance to lower temperature cracking and rutting was investigated by indirect tensile strength test. Stripping due to frost and thawing action was investigated by moisture induced damage test. After conducting all tests, it can be concluded that CRMB showed higher softening point and lower stripping value. Water sensitivity tests indicate modified bituminous mixes showed higher resistance to moisture induced damage, lower temperature cracking and rutting which in turn alludes less maintenance work is needed for CRMB road. So, it can be said that CRMB is a sustainable solution for durable and efficient road construction in Bangladesh considering economically and environmentally.