Research Projects

Emerging technologies that reduce emissions and utilize fewer natural resources contribute to sustainable pavement construction. The use of cold bituminous technology in pavement construction is the better alternative pavement construction technology in terms of safety and sustainability compared to hot bituminous technology. However, to resist pavement deformation, cold bituminous mixes must satisfy paving mixture requirements, such as rut resistance, fatigue life, and durability under adverse temperature conditions. Cold bituminous mixes comprise aggregates, bitumen emulsion or foamed bitumen, and water. These are considered sustainable paving materials because, in pavement construction, all activities such as prewetting of aggregate, the addition of bitumen emulsion, production, laying, and compaction mixes are carried out at ambient temperature (Doyle et al. 2013; Fang et al. 2016). Cold bituminous mix perks include the ability to pave in cold weather, substantially reducing greenhouse gas emissions, improved working conditions, and economic cost-effectiveness (Dulaimi et al. 2016). In India, more than 90% of the existing road pavements are constructed as bituminous pavements (MoRTH, 2023). Generally, the paving mix is produced and constructed with hot mix technology. However, despite its general acceptance, hot mix technology has a lot of shortcomings, such as pollution, higher energy consumption, an increase in carbon footprint, lower mix production output, significantly reduced laying work in rainy and cold weather, a short construction season per year, oxidative hardening of the binder, risks to worker health and safety, etc. (Pundhir, 2012). The behaviour of a rheological viscoelastic bituminous binder depends on the temperature and loading rate (Kim et al., 2009). How bitumen emulsion interacts with filler particles, chemical reactions, hydration processes, hydration product formation rate, and the mastic's subsequent stiffening can influence the performance of cold bituminous mixes. Rheological characterization aids in determining how the filler type and content affect the mastic stiffness and corresponding mix performance. The mixture of binder and filler with particle size smaller than 75 μm is termed mastic (Little et al., 2018; Chen et al., 2019; Gundla et al., 2017). A thorough understanding of micro-structural and rheological properties enables researchers and engineers to develop solutions that mitigate the issues related to cold bituminous mixes, ultimately leading to better-quality road surfaces. This study proposes a laboratory-based investigation of the microstructural and rheological characteristics of emulsified bitumen-filler mastic on cold bituminous mixes. The main aim of this project is to evaluate the performance of cold bituminous mixes with blended fillers mastic under adverse weather conditions. This study is applicable to lay roads with cold bituminous mixes at low, medium, and heavy traffic conditions.