ROLE OF CRACKS IN DELAYED ETTRINGITE FORMATION

摘要

The role of cracks in expansion due to delayed ettringite formation is controversial. Some researchers claim that expansion occurs throughout the paste and that cracks form as a consequence of the stresses created in the concrete due to the heterogeneous arrangement of the aggregates and that ettringite subsequently recystallises into these cracks. Others claim that the growth of ettringite in cracks, causing them to widen and extend, is the principal mechanism of expansion. This paper reviews some aspects of this question and presents some preliminary results of numerical simulation, illustrating how uniform expansion in the paste phase may lead to a complex crack pattern due to the propagation of existing cracks.