Influence of Mix Parameters on Development of Sulfur Modified Bituminous Paving Mixes with Sand

Abstract

Aggregates obtained from natural stone resources is the main source of infrastructure including road-pavement construction. To keep pace with economic development, rapid industrialization and urbanization, the natural stone resources are being depleted at an alarming rate, which is a major concern for future construction. Keeping this issue in mind, the use of alternative materials to aggregates for construction is a major research interest. Since sand is available abundantly in some places, such as: coastal deltaic plains and desert areas, it is necessary to evaluate the potential of sand as an alternative to the stone aggregates. But, because of its low stability, sand-bituminous mix was not found to be suitable for pavement construction. The advantageous effects of using sulfur with construction materials motivated the authors to develop sand-bitumen mixes modified by locally available commercial sulfur.

This research addressed the procedure to develop the sulfur modified bituminous mixes. Based on an earlier study, a Sand-Sulfur-Bitumen (S-S-B) mix comprising of poorly graded river sand, sulfur and VG 30 bitumen with proportion of 85:10:5 by weight was selected. The influence of mixing parameters such as: mixing sequences, mixing temperature and mixing time on performance characteristics of the mix was evaluated. The characterization of the mix was based on Marshall test due to its easy availability and widely usage for mix design. It was concluded that best results were obtained when the molten sulfur was added to heated sand and mixed for about 90s, followed by mixing of all the ingredients for about two minutes at a mixing temperature of 150°C.