Life Cycle Impact Assessment (Cradle-to-Gate) of Fiber-Reinforced Concrete Application for Pavement Use: A Case Study of Islamabad City

It is well-know that PC is vulnerable to sudden failure under 'tensile' and/or 'flexural' loading; hence, it yields large structural dimensions when used for tensile load applications. A discrete fiber-reinforcement advances the ductility and tensile strength of Plain concrete (PC); therefore, Fiber-reinforced concretes (FRCs) require structural dimensions smaller than PC under same tensile loading conditions. In this study, the effect of fiber type and content is evaluated and analyzed on the life cycle cost and CO2-footprint of concrete pavement. Namely three types of fiber-reinforced concretes, i.e., Steel fiber-reinforced concrete (SFC), Glass fiber-reinforced concrete (GFC), and Polypropylene fiber-reinforced concrete (PFC) were considered for pavement application and three different fiber contents, i.e., 0, 0.5 and 1% (by volume). For the case study, location of design pavement was considered in the Islamabad city. Pavement thickness was designed for three types of streets, i.e., residential, collector, and major arterial (consideration for low to high traffic volumes). Analysis of results revealed that for different loading conditions or types of streets, PC pavement produces higher CO2-emission and is uneconomical compared to the FRC pavements. The results show the superiority of SFC over GFC and PFC in overall mechanical performance. SFC has higher associated footprint than other FRCs. Despite lesser mechanical performance compared to SFC; GFCs and PFCs show the highest reductions in the cost and CO2-footprint of the pavement (i.e., Cost per unit area of pavement (CPA) and Global warming potential per unit area of pavement (GWPPA)).

Automated summary

This study evaluates the impact of different fiber types and contents on the life cycle cost and CO2-footprint of concrete pavement. The results show that steel fiber-reinforced concrete performs better than glass fiber-reinforced concrete and polypropylene fiber-reinforced concrete in terms of overall mechanical performance, but it has a higher carbon footprint. In contrast, glass fiber-reinforced concrete and polypropylene fiber-reinforced concrete demonstrate the highest reductions in pavement cost and carbon footprint.