Ageing factor for fly ash cement concrete (FACC)

Area of Science:

• Civil Engineering
• Materials Science
• Durability of Concrete Structures

Background:

• Concrete durability in aggressive environments, particularly marine settings, is a significant concern.
• Chloride ingress is a primary cause of reinforced concrete degradation, impacting service life.
• The failure of structures like the Miami Building highlights the need for reliable service life modeling.

Purpose of the Study:

• To evaluate the performance of existing ageing factors in service life modeling of fly ash cement concrete (FACC).
• To address the discrepancies in predicted service life due to variations in ageing factors.
• To develop a new, more reliable ageing factor for FACC in chloride environments.

Main Methods:

• Literature survey to collect long-term chloride diffusion coefficient (D) values for FACC.
• Analysis of existing ageing factors used in service life modeling.
• Development and validation of a novel ageing factor for FACC.

Main Results:

• Significant variations were observed in predicted service life using different available ageing factors.
• The selection of ageing factors critically influences the accuracy of service life modeling.
• A new ageing factor was developed, showing potential for more reliable predictions.

Conclusions:

• Existing ageing factors provide inconsistent results for FACC durability modeling.
• The newly developed ageing factor offers improved reliability for service life modeling of FACC in chloride-rich environments.
• Accurate service life prediction is essential for ensuring the longevity of concrete structures.