Experimental Behavior of Waste Polyethylene and PVC on the Compressive Strength of Bituminous Mixes
As a binding material, bitumen is widely used for the construction of wearing course of flexible pavement. The durability of the bituminous mix can be enhanced by use of a binder formed by modifying available bitumen with certain additives like sulphur and organic polymer. The modified binder also improve temperature susceptibility and viscosity characteristics and help alleviating some common problems like bleeding of binder during peak summer temperature and stripping of aggregate in moisture prone areas. The aim of this study is to use of polyethylene and PVC as admixture to bitumen to introduce high quality bituminous mixes for the road construction. This investigation presents some of the experimental results regarding the effect of water on the compressive strength of compacted bituminous mixes with waste polyethylene and PVC. In this investigation 10% waste polyethylene and 7.5% waste PVC was added to the pure bitumen as an admixture to study the compressive strength of the mix. Marshall mix design procedure specified by AASHTO T245-82 was followed in the design and testing of bituminous mixes. On the basis of experimental results of this investigation, optimum bitumen content (OBC) for pure bitumen, polyethylene modified bitumen and PVC modified bitumen were 5.3%, 5.2% and 5.27% respectively. To investigate the effect of water on the compressive strength of bituminous mixes with modified bitumen, specimens were prepared and tested according to the procedures specified by AASHTO T165-86. In this study, the index of the retained strength for both polyethylene and PVC modified bitumen were 89.89% and 85.06% respectively which satisfy the limiting value 75% specified by the ASTM.