laitance means A weak, milky layer of cement and aggregate fines on a concrete surface that is usually caused by an overwet mixture, overworking the mixture, improper or excessive finishing or combination thereof. Also, could be caused when a slurry mix is used on a deep foundation, where the slurry mix is not completely removed before placing concrete on top. Lexicurio rates it Sui generis — a strength score of 88 out of 100.
Etymology
From French laitance.
noun
- A weak, milky layer of cement and aggregate fines on a concrete surface that is usually caused by an overwet mixture, overworking the mixture, improper or excessive finishing or combination thereof. Also, could be caused when a slurry mix is used on a deep foundation, where the slurry mix is not completely removed before placing concrete on top.
- The weak top layer of cement and aggregate fines on a concrete surface that stands between a topical coating and the underlying substrate. This laitance layer prevents a bond forming between the topical coating and substrate, whereby it causes delamination of the topical coating as the laitance layer fails first.
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