Effect of Mixture Design Parameters and Cover Depths on the Durability of Concrete Members under Climate Change

Abstract

Climate change is one of humankind’s most important challenges in the 21st century. Carbon dioxide emissions are one of the most critical factors that cause this phenomenon. On the other hand, the penetration of carbon dioxide and its diffusion in the concrete lead to the carbonation phenomenon, which threatens the durability of concrete constructions. The shift toward sustainable construction by extending the operational life span of concrete constructions necessitates a thorough comprehension of factors influencing durability and careful consideration of various uncertainties. To this end, the present research utilizes the capabilities of the Monte Carlo simulation method to investigate the durability of concrete structures against climate change, taking into account a broad range of existing uncertainties. Based on numerical and probabilistic studies conducted on this topic for 100 years, it was observed that by reducing the water-to-cement ratio from 0.7 to 0.45, the durability of concrete increased by more than 40%. Also, using 411 kg of cement instead of 336 kg per cubic meter of concrete increased the durability of a structure by about 8%. Meanwhile, by increasing the effective depth of the cover from 20 to 30 mm, the durability of the concrete member increased by about 80%. Limitations of this study include its focus on specific mix design variables and climate change scenarios, potentially overlooking other factors affecting concrete durability. Future research could explore the impact of alternative materials and more complex climate change scenarios on the carbonation process and corrosion initiation probability. Furthermore, validation through laboratory investigations is essential to ensure the accuracy of numerical simulations.