Abstract
Effectively managing stormwater runoff is crucial for minimizing the adverse impact of heavy rainfall events such as flooding and irrecoverable damages in asphalt pavements. To optimize stormwater management strategies and prevent flooding of roads and streets, it is essential to understand the structural, functional and durability behavior of both dense and open graded bituminous pavements under adverse rainfall conditions. The present study aimed to investigate a trial/Selected Grade (SG), Open Graded Friction Course (OGFC) as per IRC: 129-2019 and Bituminous Concrete Grade-2 (BC-2) with VG-40, PMB-40, and CRMB-55 as binders. Additionally, pelletized cellulose fibers (0.3% by weight of aggregates) and induction sensitive steel fibers (5% by weight of aggregates) were used only in SG and OGFC mixes for the study. The Marshall specimens prepared for the mentioned mixes were subjected to various laboratory tests to investigate and compare the structural, functional and durability characteristics. The laboratory results obtained were later used to compare, simulate and observe the behavior of the mentioned mixes to manage surface runoff and curb urban flooding using SCS Curve Number Method and QSWAT3-1.6.5 software. Koramangala in Bangalore city was selected as the potentially flood prone zone among 10 severely vulnerable zones and 19 moderately vulnerable zones for simulation based on Bruhat Bengaluru Mahanagara Palike’s (BBMP’s) urban flood report for the year 2020-21. The research findings indicates that BC-2 possessed 25.11% better Marshall Stability and 2.65% better Indirect Tensile Strength (ITS) compared to the open graded mixes (OGFC and SG) with CRMB-55 as binder. It was also observed that BC-2 had 7.11% more resistance to moisture compared to open graded mixes (OGFC and SG) with CRMB-55 as binder. On the contrary, among the open graded mixes, OGFC indicated 91.66% and 81.26% better permeability and abrasion resistance respectively compared to BC-2 mix. Based on the rainfall simulation conducted it was observed that the surface runoff on BC-2 mix using SCS Curve Number Method was 42.18% and using QSWAT3-1.6.5 software was 31.25% more than the open graded mixes considered for the study. The simulation also indicated that BC-2 mix had 30.07% more discharge than the open graded mixes. It was also observed that open graded mixes had 65.70% more infiltration compared to BC-2 mix. The research concludes that the open graded mixes are comparatively less strong than BC-2 mix but, on the contrary performs better in curbing urban floods and hence could be considered as a sustainable infrastructure solution.