Laboratory testing and investigations of delayed ettringite formation
MetadataShow full item record
Delayed ettringite formation (DEF) in concrete structures has recently damaged structures in the state of Texas, which has caused the state to investigate this new type of premature concrete deterioration. The research described in this thesis is part of a comprehensive research project, TxDOT Project 4085. The work described in this thesis focuses primarily on DEF, but also investigates the interplay between DEF and alkali-silica reaction. Significant accelerated laboratory testing was performed, and parallel exposure blocks were cast to evaluate realistic exposure conditions. The research included materials from throughout the state of Texas. The effects of material composition and dosage on DEF were investigated, and several mitigation measures were identified that can prevent DEF-induced expansion, even when concrete is heated above 70 °C. The key findings from this research have been implemented by TxDOT in new state specifications to prevent DEF in prestressed concrete elements.