Tag Archive for Tag: DEF

Tag: DEF Microstructural features and proposed mechanisms of DEF expansion

Samples which have undergone DEF exhibit a characteristic microstructure after expansion, in which clear rims are seen around aggregate particles, largely filled with oriented ettringite. To some degree the thickness of the rims follows the size of the aggregate particles, although not all rims are continuous or filled and there are additional cracks through the cement paste. The diversity of

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Tag: DEF Factors affecting severity of DEF

DEF is a fairly weakly expansive mechanism, and so is likely to be less severe in dense flaw-free pastes and concretes. This is clearly seen by the significant effect of the constraint present around cement paste on the onset and magnitude of expansion. Grattan-Bellew et al. (1998) showed that, for ASR-inactive quartz aggregate, the rate of expansion was inversely proportional

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