Delayed ettringite formation (DEF) is a complex deterioration mechanism in concrete that can significantly affect the long‑term performance and serviceability of structures. This episode of Inside BG&E examines DEF from an engineering and research perspective, with a focus on practical implications for projects in Australia. 

Senior Materials Engineer Dr. Yogesh Ramu (BG&E, Perth) explains what DEF is, how it develops in concrete subjected to elevated temperatures during curing, and the conditions under which it becomes a durability concern. Drawing on his Australian‑specific PhD research, Yogesh discusses the distinction between deleterious and non‑deleterious DEF, the characteristics of local cements and aggregates, and why overseas research cannot always be applied directly to Australian projects. 

The conversation covers: 

• The mechanism of delayed ettringite formation in concrete 

• The influence of heat curing, moisture and material composition on DEF 

• Differences between Australian and overseas cement systems and exposures 

• How DEF can impact structural performance, service life and maintenance strategies 

• The role of BG&E’s materials team in durability planning, thermal control, mix optimisation and risk mitigation 

This episode is intended for asset owners, designers, specifiers and project managers seeking a clearer understanding of DEF and how specialist materials advice can support more durable, sustainable concrete infrastructure.