A Study on the Design of Sustainable Bituminous Concrete Pavement with Subgrade Soil Stabilization

The design and construction of sustainable bituminous concrete pavements are playing a critical role across countries with the rapid growth of transport infrastructure. Transporting subgrade soil having good engineering properties with more lead distances is not a sustainable option. The main aim of the research paper is to study the effect of stabilized subgrade soil in the Mechanistic-Empirical design with two cross sections of traditional aggregate bases subbase (Type-I) and cement-treated subbase layers (Type-II). The life cycle cost analysis and life cycle analysis of the bituminous concrete pavement were carried out to assess the economic viability and carbon footprint estimation using the Net Present Value method and Cradle to Grave approach respectively. From the recent literature, two stabilized subgrade soils (a) CL soil stabilized with 7.5% Flyash and Eko soil enzyme (Case-I) and (b) CL with 5% Lime stabilized (Case-II) were considered for pavement design. All other required data for pavement design and the density of materials used for construction were assumed. From the results, it is observed that the life cycle cost of Type II bituminous concrete pavement with Case-II subgrade soil is 37% less compared with Type-I pavement with Case-I subgrade soil. In the case of Type-II pavement with Case-II, subgrade soil the carbon footprint reduces up to 53% compared with Type-I pavement with Case-I subgrade soil. From this, it can be concluded the Type-II bituminous concrete pavement designed with Case-II subgrade soil is more sustainable improving the long-term life of the pavement without critical failures like fatigue cracking and wheel path rutting.