Evaluation of Delayed Ettringite Formation through Physical, Mechanical, and Microstructural Assays

摘要

This experimental study evaluated the influence of delayed ettringite formation (DEF) on physical and mechanical properties and also microstructural characteristics of concretes cast in laboratory for 6 months. The results show that DEF can generate high expansions, in the order of 1%, and reduce mechanical properties, such as compressive strength, tensile strength, and the modulus of elasticity by more than 50%. Already in the 28th day, the presence of ettringite could be identified in the concrete matrix. The results of the study indicate high premature deterioration of the concrete and, consequently, its disqualification for use after the thermal cure adopted.