Study on Comparision of Life Cycle Cost Between White Topping and Btiuminuos Overlays

Abstract

Abstract: The focus of the present study is on construction of long-lasting and better performing pavements. Usually, with respect to the rehabilitation of the pavement, the construction agencies go with the bituminous overlays as their first priority without considering the condition of the existing pavement structure. But the advantages of cement concrete (CC) pavements that have proved to perform better and are considered to be long-lasting must be explored. The use of Thin White Topping (TWT), and Ultra-Thin White Topping (UTWT) pavements is currently gaining popularity in the area of pavement construction.. And hence it is the era where the Thin and Ultra-Thin White Topping methods are gaining their popularity. The present study provides details on the approaches adopted in measuring the performance of TWT and UTWT pavement surfaces built of plain cement concrete, cement in cement concrete replaced by 50% ground granulated blast furnace slag, cement in cement concrete replaced by an admixture called Conplast NC, and 50% of cement in cement concrete replaced by GGBS and Conplast NC. The study also includes comparison of strength of composite beams of various thicknesses when subjected to repeated wheel loads under Modified Immersion Wheel Tracking Equipment when supported by a 50mm thick bituminous layer below. The performance results on the tests on the specimens of 150mm thick admixture-added CC beam and the 100mm thick GGBS-cumAdmixture-added CC beam were almost the same. This indicated that the thickness of cement concrete slabs could be reduced by 50mm by replacing 50% of cement in cement concrete with GGBS-cum Admixture-added CC beam. Based on the study on cement concrete, and composite beams, and the study of life cycle costs, it was observed that a road surface with cement concrete overlay would be more appropriate when compared to a bituminous concrete (BC) overlay. Together, these findings suggest that the concrete overlay acts as the most economic method.